jansz-io drilling environment plan

MOBIL AUSTRALIA RESOURCES COMPANY PTY LIMITED

JANSZ-IO DRILLING

ENVIRONMENT PLAN

For and on behalf of the Proponent

Document No: AUJZ-EDD-07-DR-511-R01-0071 Revision: 1

Revision Date: November 2011

Development

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN

AUJZ-EDD-07-DR-511-R01-0071 Jansz-Io EP Rev 1.doc iii

Development

CONTENTS

1 INTRODUCTION 9

1.1 Gorgon Project 9

1.2 Proponent 9

1.3 Jansz-Io Work Operator Scope 10

1.4 Environmental Approvals 10

1.5 Purpose of this Environment Plan 11

1.6 Objectives 11

1.7 Reference to Requirements 11

1.8 Operations Integrity Management System 12

2 RELEVANT ENVIRONMENTAL LEGISLATION 14

3 PROJECT DESCRIPTION 16

3.1 Programme Overview 16

3.2 Well Locations 18

3.3 Typical Jansz-Io Well Operations Sequence 18

3.4 Jansz-4 Re-Entry 20

3.5 Project Timing 20

3.6 Previous Exploration and Production 20

3.7 Drilling Activity 20

3.8 Drilling Safety 33

3.9 Shallow Gas 33

4 EXISTING ENVIRONMENT 34

4.1 Physical Environment 34

4.2 Benthic Species 38

4.3 Sea snakes 39

4.4 Turtles 39

4.5 Mammals 40

4.6 Seabirds 43

4.7 Fish 43

4.8 Conservation and Heritage Status 46

4.9 Social Environment 46

5 ENVIRONMENTAL IMPACTS, RISK ASSESSMENT AND MANAGMENT 49

5.1 Hazard Identification 49

5.2 Risk Scenario 49

5.3 Risk Matrix 51

5.4 Risk Reduction Measures 51

5.5 Environmental Hazard and Risk Assessment 51

5.6 Environmental Risk Register 52

6 DESCRIPTION OF ENVIRONMENTAL EFFECTS AND RISKS 53

6.1 Disturbance to Marine and Benthic Communities 53

6.2 Use of Chemicals and Radioactive Materials 54

6.3 Discharges Associated with the MODU 56

6.4 Well Test Emissions and Discharges 69

6.5 Deck Drainage 70

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN

AUJZ-EDD-07-DR-511-R01-0071 Jansz-Io EP Rev 1.doc iv

Development

6.6 Waste Management 75

6.7 Introduction of unwanted aquatic organisms via ballast water and hull fouling 76

6.8 Interference with Commercial Fisheries 76

6.9 Interference with Shipping 77

6.10 Interference with Recreational Users 78

6.11 Exhaust Gas, Fuel Use and Incinerator Emissions 79

6.12 Acoustic Noise including Seismic Profiling 79

6.13 Accidental Discharges 81

6.14 Environmental Risk Summary 86

7 PERFORMANCE OBJECTIVES, STANDARDS AND CRITERIA 87

7.1 Environmental Goals 87

7.2 Performance Measures 87

7.3 Review and update of the Environment Plan 87

8 IMPLEMENTATION STRATEGY 95

8.1 Systems, Practices and Procedures 95

8.2 Third Party Contractor Management 98

8.3 Roles and Responsibilities 99

8.4 Training, Communications and Awareness 103

8.5 Performance Measurement and Reporting 103

8.6 Consultation 107

8.7 Emergency Preparedness and Response 108

9 REFERENCES 110

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN

AUJZ-EDD-07-DR-511-R01-0071 Jansz-Io EP Rev 1.doc v

Development

FIGURES

Figure 1-1 Location of Jansz-Io Area 10

Figure 1-2 ExxonMobil OIMS Framework 13

Figure 3-1 Jansz Drill Centre locations 16

Figure 3-2 Transocean Deepwater Frontier 22

Figure 3-3 Jansz-Io Generalised Well Design 23

Figure 3-4 Jansz-Io Cement Programme Design 27

Figure 3-5 Well Bore Schematic 30

Figure 4-1 Wind Direction 37

Figure 4-2 Whale Migration Paths (DEWHA, 2006) 42

Figure 6-1 Representative Cuttings Processing System and NADF Recovery System 64

Figure 6-2 Shipping routes and ports in North West Region (GA, 2007) 78

Figure 8-1 Transocean-ExxonMobil/Contractor Interface 100

Figure 8-2 Organisational Chart 101

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN

AUJZ-EDD-07-DR-511-R01-0071 Jansz-Io EP Rev 1.doc vi

Development

TABLES

Table 1-1 EPBC Reference 2005/2184 requirements for Jansz-Io Drilling Activities 12

Table 3-1 Jansz-Io drilling programme and reservoir conditions 17

Table 3-2 DC-1 Wells – Seafloor Coordinates 18

Table 3-3 DC-2 Wells – Seafloor Coordinates 18

Table 3-4 Transocean Deepwater Frontier Specifications 21

Table 3-5 Summary of Discharges from Drill Centre 1 25

Table 3-6 Summary of Discharges from Drill Centre 2 26

Table 3-7 Support Vessel Specifications 31

Table 3-8 Jansz-Io Field Proximity and Travel Time 32

Table 4-1 Wave Dominant (non-cyclonic) Return Period – Summer (Oct to Mar) 35

Table 4-2 Wave Dominant (non-cyclonic) Return Period – Winter (Jun – Aug) 35

Table 4-3 Wave Dominant (non-cyclonic) Return Period – Transition Period (Sep/ Apr / May) 35

Table 4-4 Wind Dominant (non-cyclonic) Return Period – Summer (Oct to Mar) 35

Table 4-5 Wind Dominant (non-cyclonic) Return Period – Winter (Jun to Aug) 36

Table 4-6 Wind Dominant (non-cyclonic) Return Period – Transition Period (Sep/ Apr/ May) 36

Table 4-7 Cetaceans of national environmental significance that may occur in the Jansz-Io well area 41

Table 4-8 Invertebrates likely to be found near the Jansz-Io well area 43

Table 4-9 Oceanic Fishes 45

Table 4-10 Commercial Fisheries in Commonwealth Waters 47

Table 5-1 Environmental Impact Consequence Levels 50

Table 5-2 Probability Ranges 50

Table 5-3 Risk reduction philosophy 51

Table 6-1 Constituents of Drilling Fluid 58

Table 6-2 List of Non-rated Chemicals (Jansz-Io drill campaign) 59

Table 6-3 Typical noise levels associated with drilling activities 80

Table 7-1 Summary of Performance Objectives, Standards and Criteria 88

Table 8-1 Summary of Management Actions 96

Table 8-2 Third Party Contractors and Equipment Inventory for Jansz-Io 99

Table 8-3 Roles and Responsibilities 102

Table 8-4 Summary ExxonMobil environmental monitoring/recording requirements 104

APPENDICES

1. Environmental Risk Register

2. Jansz-Io Drilling Chemicals list

3. ExxonMobil Environment Policy

4. EPBC Act Protected Matters Report

5. Qualitative Risk Matrix

6. Jansz-Io Oil Spill Contingency Plan

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN

AUJZ-EDD-07-DR-511-R01-0071 Jansz-Io EP Rev 1.doc vii

Development

ABBREVIATIONS/ACRONYMS

ABBREVIATION/ ACRONYM

DESCRIPTION

AEMT (Chevron Australia) Asset Emergency Management Team

ALARP As Low As Reasonably Practical

AMSA Australian Maritime Safety Authority

APPEA Australian Petroleum Production and Exploration Association

ARI Assessment on Referral Information

BHA Bottom Hole Assembly

BoM Bureau of Meteorology

BOP Blowout Preventer

Chevron Chevron Australia Pty Ltd ( Jansz-Io Unit Operator (JIUO))

CHARM Chemical Hazard and Risk Management Model

CMS Computerised Management System (Transocean)

CTLF Coiled Tubing Lift Frame

CVX Chevron Australia Pty Ltd

DA Designated Authority

DC Drill Centre

DH Down-hole

DMP Department of Mines and Petroleum (Western Australia)

DP Dynamic positioning

DWF (Transocean) Deep Water Frontier (MODU)

EMDC ExxonMobil Development Company

EP Environment Plan

EPBC Environmental Protection, Biodiversity and Conservation Act

ERM Emergency Response Manual

ERP Emergency Response Plan

FIV Formation Isolation Valve

FSIV Fast Supply and Intervention Vessel

FWHP Flowing Wellhead Pressure

GP Gravel Pack

IMS International Maritime Safety

JA Joint Authority

JIWO Jansz-Io Work Operator

MARC Mobil Australia Resources Company Pty Limited (Jansz-Io Work Operator (JIWO))- ExxonMobil Subsidiary

LAO Linear alpha olefins

LWD Logging While Drilling

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN

AUJZ-EDD-07-DR-511-R01-0071 Jansz-Io EP Rev 1.doc viii

Development

ABBREVIATION/ ACRONYM

DESCRIPTION

MODU Mobile Offshore Drilling Unit (refers to the Transocean Deep Water Frontier Drill Ship)

NADF Non-Aqueous Fluid (low-toxicity)

NAFPac Non Aqueous Fluid Pack

NGER National Greenhouse Emissions Reporting Scheme

nm Nautical mile

NOPSA National Offshore Petroleum Safety Authority

NWS North West Shelf

OCNS Offshore Chemical Notification System

OHGP Open hole gravel pack

OIM Offshore Installation Manager

OIMS Operational Integrity Management System (ExxonMobil)

OPGGSA Offshore Petroleum and Greenhouse Gas Storage Act 2006

OSCP Oil Spill Contingency Plan

PBR Polished Bore Receptacle

POOH Pull Out Of Hole

Proponent Chevron Australia Pty Ltd

ROC Retained on Cuttings (oil)

ROV Remotely Operated Vehicle

SEWPAC Department of Sustainability, Environment, Water, Population and Communities (Commonwealth)

SHE Safety, Health and Environment

SIMOPS Simultaneous Operations

SIWHP Shut-in Well Head Pressure

SSTT Subsea Test Tree

TH Tubing Hanger

TO Transocean International (Deepwater Frontier MODU Owner and Operator)

TD Total Depth

TR-SCSSV Tubing Retrievable Surface Controlled Subsurface Safety Valve

UUOA Jansz-Io Unitisation and Unit Operating Agreement

VSP Vertical Seismic Profiling

WA Western Australia

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN

AUJZ-EDD-07-DR-511-R01-0071 Jansz-Io EP Rev 1.doc Page 9 of 120

Development

1 INTRODUCTION

1.1 Gorgon Project

Construction activities have commenced for the Gorgon Project which will develop gas reserves of the Greater Gorgon Area including the Jansz-Io field.

Subsea gathering systems and subsea pipelines will be installed to deliver feed gas from the Gorgon and Jansz–Io gas fields to the west coast of Barrow Island. The feed gas pipeline system will be buried as it traverses from the west coast to the east coast of the Island where the system will tie into the Gas Treatment Plant located at Town Point. The Gas Treatment Plant will comprise three Liquefied Natural Gas (LNG) trains capable of producing a nominal capacity of five Million Tonnes Per Annum (MTPA) per train.

The Gas Treatment Plant will also produce condensate and domestic gas. Carbon dioxide (CO2), which occurs naturally in the feed gas, will be separated during the production process. The separated CO2 will be injected into deep formations below Barrow Island. The LNG and condensate will be loaded from a dedicated jetty offshore from Town Point and then transported by dedicated carriers to international markets. Gas for domestic use will be exported by a pipeline from Town Point to the domestic gas collection and distribution network on the mainland (Figure 1-1).

1.2 Proponent

Chevron Australia Pty Ltd (Chevron) is the proponent of EPBC 2005/2184 (in relation to Environment Protection, Biodiversity & Conservation Act, 1999, the unit operator under the Jansz-Io Unitisation and Unit Operating Agreement (UUOA)1 [Ref 33] and operator under all other related Gorgon Project commercial agreements. Mobil Australia Resources Company Pty Limited (referred to in this document as “ExxonMobil”2) is delegated operator responsibility by the parties to the UUOA, including Chevron, for certain Jansz-Io work activities which are described in paragraph 1.3 below..

As the Jansz-Io work operator (JIWO), ExxonMobil has the primary responsibility (as between the parties to the UUOA), using ExxonMobil systems and procedures, to prepare and submit all necessary documents and applications for drilling and to fulfil the requirements of all applicable legislation and obligations of the conditional environmental approvals granted to the Gorgon Project as they apply to the Jansz-Io development drilling activities.

Therefore, in preparing this Jansz-Io Drilling Environment Plan (EP) ExxonMobil as JIWO, has the delegated responsibility as;

operator of the Jansz-Io Production Licences WA-36, 39 and 40-L (in relation to Offshore Petroleum & Greenhouse Gas Storage Act, 2009), and as

proponent of EPBC 2005/2184 (in relation to Environment Protection, Biodiversity & Conservation Act, 1999).

Once the drilling and completion of the Phase 1 Jansz-Io wells is complete, in accordance with the UUOA, all further operator responsibility for the Jansz-Io wells and the Jansz-Io development will be the responsibility of Chevron as UUOA Operator..

Close coordination and alignment between ExxonMobil and Chevron will be maintained on all aspects of the work including simultaneous operations, logistics and emergency response.

.

1 The parties to the UUOA are: Chevron Australia Pty Ltd, Chevron (TAPL) Pty Ltd, Mobil Australia Resources Pty Ltd, Shell Development (Australia) Pty Ltd, BP Exploration (Alpha) Pty Limited, Osaka Gas Gorgon Pty Ltd, Tokyo Gas Gorgon Pty Ltd and Chubu Electric Power Australia Pty Ltd.

2 The term “ExxonMobil” as used in this EP may also refer to Exxon Mobil Corporation, or to one of its affiliates, in addition to Mobil Australia Resources Company Pty Limited and is used merely for convenience and simplicity.

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

1.3 Jansz-Io Work Operator Scope

ExxonMobil, as the Jansz-Io Work Operator, will undertake the activities as set out of the UUOA. In summary, these activities consist of the Phase 1 drilling and completion of the 10 Jansz-Io development wells and the conversion of the Jansz-4 appraisal well to a pressure monitoring well, as set out in the Jansz-Io Field Development Plan submitted to the Joint Authority in support of the application for Jansz-Io Production Licences. Details of the project are described in Section 3.

This EP forms part of the work activities and covers the environment management measures required for the Jansz-Io Phase 1 drilling activities.

1.3.1 Location

The Jansz-Io field is situated on the western flank of the Kangaroo Syncline, in the Carnarvon Basin on the North West Shelf of Australia. It is 70 km North West of the Gorgon Gas Field, 140 km North West of Barrow Island, 140 km east of the Scarborough Gas Field and 239 km from Dampier, which is the nearest port on the coast of Western Australia. Water depths vary from 1200 to 1400m. Figure 1-1 shows the location of the field.

Figure 1-1 Location of Jansz-Io Area

1.4 Environmental Approvals

The Jansz Feed Gas Pipeline was assessed via Environmental Impact Statement/Assessment on Referral Information (ARI) and EPBC Referral assessment processes (Mobil Australia-2005-2006). The Jansz Feed Gas Pipeline was approved by the Western Australian State Minister for the Environment on 28 May 2008, by way of Ministerial Implementation Statement No. 769 (Statement No. 769) and the Commonwealth Minister for the Environment and Water Resources on 22 March 2006 (EPBC Reference: 2005/2184). The proponent of Statement No. 769 was transferred from Mobil Australia Resources Company Ltd to Chevron Australia Pty Ltd on 26th August, 2009. Similarly, the EPBC Reference: 2005/2184 approval was transferred from Mobil Exploration & Producing Company to Chevron Australia Pty Ltd on 9th September, 2009.

This EP covers the Jansz Feed Gas Pipeline as approved by Ministerial Implementation Statement No. 769 and EPBC Reference: 2005/2184, as it relates to the Jansz-Io Work Operator scope.

Jansz-Io FieldJansz-Io Field

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

1.5 Purpose of this Environment Plan

1.5.1 Legislative requirements

1.5.1.1 Petroleum Legislation

This EP has been prepared for submission to the Western Australian Department of Mines and Petroleum (DMP), in accordance with the provisions of the Offshore Petroleum and Greenhouse Gas Storage (Environment) Regulations, 2009 (Commonwealth).

1.5.1.2 Commonwealth Ministerial Conditions

This EP has been prepared for approval by the Commonwealth Minister for Environment (or delegate) in accordance with the provisions of the Environment Protection and Biodiversity Conservation Act, 1999 (Commonwealth) and satisfies the requirements of EPBC Reference: 2005/2184 quoted below:

1) The person taking the action must submit, for the Minister’s approval, a plan (or plans) for managing the offshore impacts of the action.

1.6 Objectives

The objective of this EP is to describe the measures taken to ensure that the Jansz-Io drilling activities are undertaken in a manner that protects environmental values and reduces impacts to the environment as far as practicable.

This EP provides the following:

A description of the proposed drilling activities.

A description of the environment in the vicinity of the proposed drilling activity.

A description of the potential environmental effects and risks associated with the proposed drilling activity.

A description of the planned management measures to minimise the risk of environmental impact which may arise from the drilling activities.

The technical aspects of the Jansz-Io wells are similar to those for wells previously drilled in the permit area. The potential environmental effects are expected to be consistent with these previous wells; however the drilling activities will occur over a longer period. Accordingly, the assessment of the environmental effects of this drilling operation considers the experience gained from the drilling of previous wells in the area, including reviews of the environmental and geological features of the area.

1.7 Reference to Requirements

This EP is required to meet all the EPBC Reference: 2005/2184 conditions relevant to the Jansz-Io Work Operator work scope. Those conditions which are relevant to the Jansz-Io Work Operator work scope are listed in Table 1-1. The remaining conditions (1(b), (c), (g), (j) and 2-5 and 7&8) are not relevant to the scope of this EP and will be covered under separate approval applications.

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

Table 1-1 EPBC Reference 2005/2184 requirements for Jansz-Io Drilling Activities

Condition No. Requirement Section Reference

1.(a) Design and construction of facilities to allow for the complete removal of all structures and components (except flow-lines) above the sea floor

Section 3

1.(d) A schedule of works Section 3.3 and 3.5

1.(e) Managing the impacts on cetaceans, including interaction procedures for aircraft, supply and construction vessels that are consistent with Part 8 of the Environment Protection and Biodiversity Conservation Regulations 2000

Section 6.11 and

Appendix 1

1.(f) Cetacean sightings reporting Section 6.11 and

Appendix 1

1.(h) Ballast water management for international construction vessels arriving in Australia in accordance with Australian Quarantine and Inspection Service Australian Ballast Water Management Requirements

Section 6.5 and

Appendix 1

1.(i) The use and disposal of drilling muds Section 3.3, 3.7, 6.3.1 and

Appendix 1

6. If the person taking the action wishes to carry out any activity otherwise than in accordance with the plans referred to in conditions 1, 2 and 3, the person taking the action may submit for the Minister’s approval a revised version of any such plan. If the Minister approves a revised plan so submitted, the person taking the action must implement that plan instead of the plan as originally approved

Section 7.3

1.8 Operations Integrity Management System

This plan will be implemented using the proprietary ExxonMobil Operations Integrity Management System (OIMS). OIMS is adopted by all ExxonMobil subsidiaries worldwide. It contains 11 Elements each of which has globally defined corporate expectations. These are implemented through formally designed and documented Management Systems. This provides for all the standard recognised requirements of safety management systems, including a process for continuous assessment and improvement and managed overall through management leadership, commitment and accountability [Ref 29]. Figure 1-2 shows the 11 Elements of OIMS.

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

Figure 1-2 ExxonMobil OIMS Framework

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

2 RELEVANT ENVIRONMENTAL LEGISLATION

The Jansz-Io field (Figure 1-1) is located in Commonwealth waters on the North West Shelf (NWS) of Australia, and is subject to Commonwealth jurisdiction. The principal Commonwealth Act to regulate the offshore petroleum industry is the Offshore Petroleum and Greenhouse Gas Storage Act, 2006 (OPGGS Act). The Offshore Petroleum and Greenhouse Gas Storage (Environment) Regulations, 2009 (Commonwealth) define the specific environmental requirements under this Act.

The objective of the Offshore Petroleum and Greenhouse Gas Storage (Environment) Regulations, 2009 is to ensure that offshore petroleum operations are performed in a way that is consistent with the principles of environmentally sustainable development through an accepted Environment Plan (EP) with agreed environmental performance objectives, standards and criteria for determining environmental performance. The EP is assessed and approved by the Department of Mines and Petroleum (DMP) also referred to as the Designated Authority (DA).

In addition to the OPGGS Act, the Environment Protection and Biodiversity Conservation Act, 1999 (EPBC Act) applies in cases where matters of national environmental significance can potentially be affected. A referral for the development of the Jansz-Io deepwater gas field was submitted under the EPBC Act. The referral was assessed and an approval decision was granted (subject to conditions) on the 22 March 2006 in the form of EPBC 2005/2184. EPBC Reference: 2005/2184 approval was transferred from Mobil Exploration & Producing Company to Chevron Australia Pty Ltd on 9 September 2009. The conditional approval requires the preparation of a plan (this EP) for managing the impacts of the action. This EP is assessed and approved by the Department of Sustainability, Environment, Water, Population and Communities (SEWPAC).

Other principal acts and codes of practice relevant to the environmental aspects of the proposed project under Commonwealth jurisdiction include:

Australian Heritage Commission Act 1975

Historic Shipwrecks Act 1976

Protection of the Sea (Prevention of Pollution from Ships) Act 1983

Australian Maritime Safety Authority Act 1990

Environment Protection (Sea Dumping) Act 198.

Hazardous Waste (Regulation of Exports and Imports) Act 1989

National Greenhouse and Energy Reporting Act 2007 (NGER Act)

Navigation Act 1976

Ozone Protection and Synthetic Greenhouse Gas Management Act 1989

Protection of the Sea (Oil Pollution Compensation Fund) Act 1993

Wildlife Protection (Regulation of Exports and Imports) Act 1982

Quarantine Act 1908

Environment Protection (Sea Dumping) Act 1981

Protection of the Sea (Harmful Antifouling Systems) Act 2006

The principal international agreements relevant to the environmental aspects of the proposed project in Commonwealth waters are:

United Nations Convention on the Law of the Sea 1982.

International Convention for the Prevention of Pollution from Ships 1973 (commonly known as MARPOL 73/78) and implemented in Australia through the Protection of the Sea (Prevention of Pollution from Ships) Act 1983.

International Convention on Oil Pollution Preparedness, Response and Co-operation 1990.

Protocol to International Convention for the Prevention of Marine Pollution by Dumping of Waste and Other Matter 1972 (commonly known as the 1996 Protocol).

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

Agreement between the Government of Australia and the Government of the People’s Republic of China for the Protection of Migratory Birds and their Environment (commonly referred to as CAMBA).

Agreement between the Government of Australia and the Government of Japan for the Protection of Migratory Birds and Birds in Danger of Extinction and their Environment (commonly referred to as JAMBA).

Convention on Migratory Species (commonly known as the Bonn Convention).

The Code of Environmental Practice relevant to the Jansz-Io drilling is the Australian Petroleum Production and Exploration Association (APPEA) Code of Environmental Practice 2008, which provides guidance on a set of recommended minimum standards for petroleum industry activities offshore. These standards are aimed at minimising adverse impact on the environment, and ensuring public health and safety by using the best practical technologies available.

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

3 PROJECT DESCRIPTION

3.1 Programme Overview

The Jansz-Io field is predominantly a gas reservoir. The composition of hydrocarbon in the Jansz-Io field has been assessed during the drilling of Jansz-1, 2, 3 & 4 and Io 1 & 2. Dry gas was found with minor volumes of associated liquid hydrocarbon (gas to oil ratio (m3:m3) of 35,213:1).

Fifteen production gas wells have been planned for Jansz-Io depletion. The wells will be phased, with an initial ten wells, Phase 1 operated by ExxonMobil as JIWO (covered by this EP), followed some years later by five additional wells, Phase 2, which will be operated by Chevron as Unit Operator under the UUOA. The Phase 1 wells will be drilled from two, six well-slot drill centres. Five wells will be located at drill centre 1 (DC-1), which is located near the Jansz-3 well location, and five wells will be located at DC-2, located near the Io-1 well location. Each drill centre contains a spare slot. Also as part of the Phase 1 drilling programme, the Jansz-4 appraisal well will be re-entered and converted to a pressure monitoring well.

The five Phase 2 wells will be located at the six well-slot Jansz DC-3 drill centre, which is near the Jansz-4 location and 3.3km ESE of the Jansz-1 well location. Phase 2 drilling is currently planned for approximately five years after commencement of production from the Gorgon Project.

Figure 3-1 provides an overview of the drill centre locations.

Figure 3-1 Jansz Drill Centre locations

All wells are designed with 2-D double-build and hold directional profiles with 80º penetrations of the reservoir to provide the desired well deliverability, with reservoir targets that fall within a 2.5km drilling radius from the mudline location. Sand control technology will be incorporated in the well completions due to the shallow, unconsolidated nature of the reservoir and the potential for sand production. All wells will be completed as open-hole gravel packs.

Following is a summary of the Jansz-Io drilling programme and reservoir conditions.

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

Table 3-1 Jansz-Io drilling programme and reservoir conditions

Location Specific Details

Designated Authority for Drilling Area (Environment)

WA Department of Mines and Petroleum

Met Forecaster Bureau of Meteorology

Operations Base Mermaid Supply Base Australia – Dampier

Permit Area Jansz-Io Production Licences WA-36, 39 and 40-L, located in Commonwealth waters

Name and Type of Well Jansz-Io (production gas wells)

Location Carnarvon Basin North West Shelf

Maximum Horizontal Displacement 2500 m

Type of Well Production

Water Depth 1200-1400 m

Drilling

Two x 6 well drill centres 5 wells each + 1 spare slot

Phasing Drill / complete drill centre 1&2 wells prior to start-up Drill/ / complete drill centre 3 wells – approximately 5 years after start-up

MODU Transocean Deepwater Frontier (DP Vessel)

Casing Programme 36” (914mm) structural, 20”(508mm) surface, 13-5/8” (346mm)production 9-5/8” (245mm) production liner

Directional Profile 2-D Double build 800 B&H

Drilling Fluids Seawater + sweeps to 20” (508mm) shoe. NADF to total depth (TD)

Wellbore Stability 10.5 ppg max required for wellbore stability

Completion Open hole gravel pack (NAFPac)

9-5/8” (245mm) 13 Cr VAM Top Tubing

7”(178mm) Tubing Retrievable – surface controlled, sub surface safety valve (TR-SCSSV)

Permanent Down-hole (DH) pressure and Temperature gauges (PDPT)

Down-hole chemical injection mandrel

7” (178mm) horizontal subsea trees

Production (Phase 1) 130-320 Mscf/d production rates

4200 psi SIWHP: 3850 psi FWHP

115-145 degF (43-63degC) FWHT

Estimated Drill Period 2- 3 years

Estimated Spud Date December 2011 to February 2012

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

3.2 Well Locations

Table 3-1 show the Jansz-Io development plan for each of the Phase 1 drill centres. At each drill centre, five wells will be drilled out from mudline locations near the manifold to bottom-hole targets contained within a 2.5 km radius circle centred on the manifolds. The approximate seafloor coordinates of the wellheads are provided in Table 3-2 and Table 3-3.

Table 3-2 DC-1 Wells – Seafloor Coordinates

DC-1 Manifold – Water Depth 1338m

Seafloor Coordinates

Well Easting Northing

Manifold 245 540.00 7 805 895.00

JZ1-1A (spare slot) 245 545.55 7 805 841.13

JZ1-1B 245 529.95 7 805 853.58

JZ1-1C 245 501.40 7 805 856.45

JZ1-1D 245 486.28 7 805 885.49

JZ1-1E 245 500.31 7 805 910.53

JZ1-1F 245 499.05 7 805 930.45

Table 3-3 DC-2 Wells – Seafloor Coordinates

DC-2 Manifold – Water Depth 1349m

Seafloor Coordinates

Well Easting Northing

Manifold 253 210.00 7 809 865.00

JZ1-2A 253 204.45 7 809 918.87

JZ1-2B 253 220.05 7 809 906.42

JZ1-2C 253 248.60 7 809 903.55

JZ1-2D 253 263.71 7 809 874.51

JZ1-2E 253 249.69 7 809 849.47

JZ1-2F (spare slot) 253 250.95 7 809 829.55

3.3 Typical Jansz-Io Well Operations Sequence

The following provides a description of the typical Jansz-Io well operations sequence (subject to optimization as operational considerations dictate).

Jansz-Io well construction activities have been planned as a series of batch operations for efficiency, with the rig moving between DC-1 and DC-2 as required. Flexibility in the well construction sequence will be required due to schedule uncertainty related to managing simultaneous operations (SIMOP), equipment delivery, and other operational considerations. The operations sequence may change so that installation of the lower completion is included with the drilling activity, prior to well suspension and the installation of the subsea tree infrastructure. Upper completions are installed after installation of the subsea trees.

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

1. Position rig over the well location.

2. Run 36” (914mm) casing/low pressure wellhead on 26” (660mm) drill head assembly. Jet in 36” (914mm) casing.

3. Drill ahead to 20” (508mm) casing point riser-less with seawater.

4. Rig-up and run 20” (508mm) casing/high pressure wellhead. Cement 20” (508mm) casing with returns to seafloor.

5. Run Blow Out Preventers (BOPs) and riser. Latch up and test BOPs.

6. Pick up 17-1/2" (445mm) rotary steerable Bottom Hole Assembly (BHA) and directionally drill to casing point with non-aqueous fluid.

7. Rig-up and run 13-5/8" (346mm) surface casing and cement. Set and pressure test seal assembly.

8. Pick up 12-1/4” (311mm) rotary steerable BHA and directionally drill to casing point with non-aqueous fluid.

9. Run and cement 9-5/8" (245mm) intermediate/production liner. Pressure test liner and cement. Pull Out Of Hole (POOH).

10. Run and set liner top packer assembly. Pressure test liner top packer. POOH.

11. Pick up and run 8-1/2" (216mm) bit x 9-7/8” (251mm) under-reamer assembly and direction drill completion interval with non-aqueous fluid.

12. Run Non-Aqueous Fluid Pack (NAFPac) lower completion assembly including Formation Isolation Valve (FIV), Set Gravel Pack (GP) packer. Perform open hole gravel pack. Shift FIV closed. POOH with wash pipe.

13. Run closure sleeve straddle seal assembly and pressure test. POOH with running assembly.

14. Set 9-5/8”(245mm) and 13-5/8” (346mm) suspension plugs and pressure test. POOH.

15. Displace riser to seawater, unlatch BOPs. Move off location.

16. Install Horizontal Christmas Tree (HXT) on High Pressure wellhead via installation vessel (offline operation).

17. Move on location with rig. Land and latch riser and BOPs to HXT.

18. Pull 9-5/8” (245mm) and 13-5/8” (346mm) suspension plugs.

19. Run wellbore cleanout assembly to FIV. Clean and filter brine as required. POOH.

20. Run Upper Completion & Tubing Hanger (TH).

21. Run in hole with Subsea Test Tree (SSTT) on 9-5/8” (245mm) landing string.

22. Rig up surface equipment. Pressure test landing string and surface equipment.

23. Land and lock Tubing Hanger. Circulate in packer fluid and base oil under-balance.

24. Set 7” (178mm) x 9-5/8” (245mm) hydrostatic-set packer (below 9-5/8” [245mm] liner top).

25. Open FIV and perform clean-up/flow-back to well test equipment on rig.

26. Perform Surface Controlled Subsurface Safety Valve (SCSSV) inflow test.

27. Circulate/lubricate in suspension fluid.

28. Install and pressure test Tubing Hanger crown plugs.

29. Unlatch SSTT, lay down surface equipment, and recover landing string and SSTT.

30. Displace riser to seawater, unlatch BOPs, and pull BOPs and riser.

31. Install environmental barrier on subsea tree (offline operation).

The Unit Operator (Chevron) has designed the subsea infrastructure for the Jansz-Io work scope (wellheads, support bases and subsea trees) to allow for removal at the time of decommissioning. An installation vessel will install the subsea infrastructure on all Jansz-Io wells. ExxonMobil’s installation process also allows for removal at time of decommissioning. After the installation vessel departs location, the Deep Water Frontier (DWF) will resume completion activity running the upper completions and completing the well clean-up operations on DC-1, followed by similar operations on DC-2, before releasing the DWF.

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

3.4 Jansz-4 Re-Entry

The Jansz-4 well, suspended in 2009, will be re-entered in order to convert this well to a reservoir monitoring well. Permanent down-hole gauges will be installed on tubing and the well then abandoned with cement plugs pumped through the tubing and hanger. The gauges will be tied into an acoustic transmission system installed on the well head, with data being retrieved through an acoustic receiver launched from a work boat.

The generic sequence for installing the monitoring well is:

• Re-enter the existing well.

• Drill out cement plugs and retainers.

• Clean up well.

• Install well completion with permanent down-hole gauges (including re-perforation).

• Abandon well with “Intelligent Abandonment” configuration with deep and shallow set cement plugs (cementing through tubing).

• Connect permanent down-hole gauges to acoustic transmission system mounted on trash cap.

• Release rig & monitor long term (periodic acoustic data downloads via “drive by vessel”).

3.5 Project Timing

Drilling of Jansz-Io is scheduled to commence between October and December 2011, with drilling expecting to continue for two to three years.

3.6 Previous Exploration and Production

3.6.1 History of Exploration in the Region

Petroleum exploration began on the North West Shelf in 1953 and the Barrow Island oilfield, declared commercial in 1964, was the second commercial oilfield in Australia. Since the late 1960s, and particularly since the 1980s, extensive exploration activities have been undertaken on the seabed underlying the open ocean off the Pilbara coast. Numerous oil and gas wells and production facilities now operate in the region, the closest to the Jansz-lo development area is the Goodwyn platform over 175 km away.

3.6.2 History of Exploration in the Jansz-Io Field

The discovery well Jansz-1 in permit area WA-18-R was drilled in April 2000. This was followed by Io-1 in January of 2001 in the adjacent permit area WA-25-R. Appraisal wells Jansz-2 and Jansz-3 were spudded in 2002 and 2003 respectively. The Jansz-3 well was production tested and confirmed the high reservoir quality and deliverability in the core development area of the Jansz-Io gas field. The Io-2 well was drilled in 2006 in WA-26-R and the Jansz-4 appraisal well was drilled in 2009 in WA-18-R.

3.7 Drilling Activity

3.7.1 Transocean Deepwater Frontier

ExxonMobil will use the Transocean Deepwater Frontier (DWF), a dynamically positioned (DP) drillship, designed to operate in 10,000 feet (3048 m) of water and currently equipped for 7,500 feet (2286m) of water. The vessel is registered in Panama and is certified by the American Bureau of Shipping +A1 (E), MODU, +AMS, +ACCU, +DP, DLA, OMBO and Cargo Gear Registry.

The DWF conforms to the American Bureau of Shipping (ABS), the United States Coast Guard (USCG) and the International Maritime Organisation (IMO) rules and regulations. The DWF will have an accepted Safety Case, as approved by the National Offshore Petroleum Safety Authority (NOPSA) with Transocean as the Nominated Facility Operator.

The vessel is ship shaped and is designed for stationary operations and primarily intended for the drilling of oil & gas wells. The drillship is double hulled and designed for DP drilling operations. The drillship is

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

designed to operate in a Gulf of Mexico type environment (cyclone zone and high seas), featuring a very high variable load capacity.

The vessel is capable of racking 37,000 feet (11278m) of drill pipe in the derrick and has a variable load capacity of in excess of 20,000 metric tons. Ample deck storage space is available, allowing for storage of 10,000 feet (3048m) of riser and casing for two wells.

Six Wartsila engines act as prime movers, capable of generating 47,000 hp. Station keeping is accomplished by the provision of six Kamewa 4,000 kw variable speed azimuthing thrusters, providing a total thrust horsepower of 32,160. Transit speed is approximately 12 knots.

A crew compliment of 160 persons can be accommodated in one and two berth cabins. Facilities within the accommodation block include: two recreation rooms, sauna, gymnasium, conference room, and mess hall for 72 persons, nine offices, computer room, navigation room, treatment room and hospital with three beds. Table 3-4 provides additional details of the DWF.

An Application to Undertake Well Specific Activities has been prepared and submitted to NOPSA for approval in accordance with the Offshore Petroleum and Greenhouse Gas Storage (Resource Management and Resources) Regulations, 2011. ExxonMobil’s drilling programme and procedures are based on the previous experience of the Jansz-Io drilling programmes.

Table 3-4 Transocean Deepwater Frontier Specifications

Rig Type 5th Generation Deepwater

Design R&B/Samsung, based on double hull

Year Built 1999 Classification ABS + A1E, MODU, FSO, + AMS, +ACCU, +DPS, DLA, OMBO, Cargo Gear Registry

Accommodation Air-conditioned to accommodate 160 people

Max Drill Depth 30,000 ft / 9,144 m

Max Water Depth 10,000 ft / 3,048 m

VDL – Operating 20,800 mt 22,928 st

Liquid Mud 5,093 bbls 28,595 cu ft 810 cu m

Drill Water 17,610 bbls 98,871 cu ft 2,798 cu m

Bulk Mud 34,000 cu ft 962 cu m

Bulk Cement 34,000 cu ft 962 cu m

Drilling Equipment

Derrick - 170 ft. high with 40 ft. x 48 ft. base

Draw-works 6600 hp; 1,500 kips hook load

Motion Compensator Active Heave

Top Drive Varco TDS-8S (AC), 750 ton, 45000 ft-lbs @ 15rpmPipe Handling 1 x Varco PHM-3i PRS

Mud Pumps 4 x National 14P220, 7500 psi

BOP 1 x 18-3/4" (476mm) Cameron TL 15,000 WP; (Single + Doubles) LMRP

Main Power Three each Wartsila 18V32 diesel electric engine generator sets arranged one each in engine rooms number one, two, and three rated at 7.0 Megawatts (9333 hp) each. Engines designed to operate on diesel or HFO

Deck Cranes 3 x 50 ton @ 43 ft (7224) Seatrax pedestal cranes, Model 7224; 1 x 85 ton @ 36 ft (8032) Seatrax pedestal crane, Model 8032; 2 x gantry cranes (pipe deck and riser storage area)

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

Figure 3-2 Transocean Deepwater Frontier

3.7.2 Generalised Well Design

The ten wells are designed with 2-D double-build and hold directional profiles with horizontal displacements ranging from ~1200m to 2500m and an 80º wellbore angle through the reservoir. This well design and directional profile optimise the draw-down/well deliverability/reservoir well interference requirements`. The high angle reservoir penetration exposes approximately 320m of the pay sand interval (assumes 55mTVT reservoir). The wells are designed to complete across the entire productive reservoir section, though some wells will not be completed in the lower wedge.

Key design limitations include:

Maximum Planned Horizontal Displacement: 2500m

Maximum Planned Reservoir Penetration: 400m

Maximum Planned Build Rate: 3 deg/30mMD

2-D directional plans (no azimuth changes)

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

Figure 3-3 Jansz-Io Generalised Well Design

3.7.3 Drilling Muds

Non-Aqueous Drilling Fluid (NADF)

The 26” (660mm) hole will be drilled riser-less using seawater and gel sweeps, with returns to the seafloor. The water based muds (WBM) to be used are classed as ‘non-toxic’, whilst the non-aqueous drilling fluid (NADF) is classified as ‘slightly toxic’.

After the 20” (508 mm) casing is run and cemented, the marine riser and BOP will be installed. The remainder of the well will be drilled with a low-toxicity NADF that has been previously approved by the regulators for use offshore Western Australia.

A NADF is used for the following technical reasons:

The NADF is required to maintain borehole stability and for the installation of high rate, reliable, long life completions utilising ExxonMobil patent NAFPac process.

In order to instil high rate, efficient open hole gravel pack completion (patented NAFPac technique), NADFs are required.

NADF is critical for maintaining wellbore stability in the near horizontal sections.

9-5/8” GP Packer & FIV

Mar

l

Press / Temp Gauges

±2860m TVD±4125m MD

36”

20”

13-5/8”

9-5/8” 13 Cr Prod Liner

±1425m TVD/MD

±1850m TVD/MD

±2600m TVD±3200m MD

±2815m TVD±3865m MD

9-5/8” 13 Cr Tubing

7” SCSSV@ ±1800m

OHGP NAFPac

Lim

esto

ne

Silt

sto

ne

& C

lays

ton

eS

and

9-5/8” Liner Hanger& Packer

±1340m WD

Horizontal Tree

9-5/8” x 7” Prod Packer

Chemical Inj Mandrel


9-5/8” GP Packer & FIV

Mar

l

Press / Temp Gauges

±2860m TVD±4125m MD

36”

20”

13-5/8”


±1425m TVD/MD

±1850m TVD/MD

±2600m TVD±3200m MD

±2815m TVD±3865m MD


7” SCSSV@ ±1800m

OHGP NAFPac

Lim

esto

ne

Silt

sto

ne

& C

lays

ton

eS

and

9-5/8” Liner Hanger& Packer

±1340m WD

Horizontal Tree

9-5/8” x 7” Prod Packer

Chemical Inj Mandrel


G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

NADF is proposed for use for drilling the 17½"(445mm), 12¼"(311mm), 8½"(216mm) and 9 7/8” (251mm) hole intervals. The NADF consists of base oil and other additives (e.g. brine, emulsifiers, viscosifiers, weighting agents). The mixing ratio and concentration of all these products is dynamic. NADF properties are monitored and modified accordingly to maintain desired specifications to achieve a safe and efficient operation.

The Jansz-Io program will use Saraline 185V as the base oil (Offshore Chemical Notification Scheme (OCNS) group D) as it is accepted for use in Western Australia. Saraline 185V will be mixed with various additives in a mud plant until the mud reaches the specification required. Generally a mix consists of approximately 60% base oil and 40% additives. Like the base oil, the additives selected for use on the Jansz-Io project have been selected to be least hazardous and where possible as a minimum will have a Chemical Hazard and Risk Management Model (CHARM)/OCNS rating of D or E or Silver or Gold. The rating indicates that the substance has low toxicity, is biodegradable and is non-bio-accumulative.

The discharge of NADF to the environment will be minimised by recycling the drilling fluid and with the use of high quality solids processing equipment to reduce the volume of NADF retained on the cuttings.

It is possible that during the blending of the NADF at the Liquid Mud Plant (LMP) some trace quantities of Linear Alpha Olefins (LAO) may exist within the Saraline as trace contaminants. These may be present from the manufacture of previous drill fluids. In order to minimise the risk of cross contamination ExxonMobil conduct Quality Assurance and Quality (QA/QC) checks of the manufacturing process and specify tolerance limits to the manufacture. However, trace quantities of LAO may still be present (which do not affect the drill fluid criteria).

3.7.4 Drill Cuttings

The Transocean DWF vessel will be equipped to properly process and handle the NADF and discharge of the cuttings will be in accordance with industry standards and ExxonMobil worldwide practices. Cuttings dryer units will be utilised to reduce the NADF retained on cuttings.

NADF will be recovered and treated to remove formation solids and the NADF will then be recycled and reused. Rock cuttings from the hole will be separated from the drilling fluid by vibrating screens (shale shakers). The shakers will be monitored and cleaned to avoid blockages. Cuttings from the shakers will be processed through a cutting dryer prior to overboard discharge.

Cuttings dryers are used to minimise the retention of NADF on rock cuttings and allow the additional recovery of drilling fluid for reuse. The cuttings dryer system and centrifuge will process the cuttings to remove the NADF. The NADF is then returned back to the active drilling fluid system and the cuttings are discharged overboard.

While the majority of used NADF will be returned to shore for reconditioning and future use, not all the drilling fluid can be removed and a coating of residual drilling fluid remains attached to the cuttings. Discharges of NADF are confined to this material adhering to the surfaces of the cuttings. Following treatment with the cuttings dryer and the centrifuge, the NADF retained on cuttings (ROC) shall be less than 10% by dry weight for the interval where NADF is used (see section 6.3.1 for detailed description). The ROC is monitored by on-board testing conducted once every twelve hours.

In the event the cuttings dryer system is not available (for example, in the event of equipment failure), the drilled cuttings will be discharged overboard after separation from the mud by the shale shakers until the cuttings dryer system is fully operational. Discharge of non-dried cuttings due to dryer downtime is unlikely to have a significant impact on the volume of NADF ROC by weight averaged over each hole section. During any down-time of the dryer system, the frequency of on-board ROC testing will be increased to once every six hours. Instances where the cuttings dryer is non-operational will be reported. In addition, two cuttings dryers will be installed thereby providing redundancy capacity in the event of one cutting dryer failing.

Table 3-5 and Table 3-6 provide the volume of cuttings discharged and volume of anticipated mud losses (ROC) per hole section for each well for DC-1 and DC-2 respectively. The 36” (914mm) section will be jetted (no returns to surface). In the event that jetting is not possible (due to encountering rock etc) consideration will be given to drilling a 42” (1067mm) hole (60m below mud line) running 36” (914mm) casing and cementing.

The 26” (660mm) section will be drilled riser-less using seawater and Water Based Mud (WBM) which are not toxic and therefore all cuttings and mud will be discharged to sea.

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

Table 3-5 Summary of Discharges from Drill Centre 1

Total Weight of Cuttings Generated & Anticipated Material Discharges to Ocean Well Hole Size

inches (mm) Interval Length

Volume of Cuttings

Weight of Cuttings

Anticipated Surface Mud Losses

Mud System

(m) (m3)

JZI-1B 36 (914) 88 m 58 m3153 Mt 390 Mt 654 Mt 158 Mt 35 Mt

95 m3 600 Bbls WBM – riserless

26 (660) 430 m 147 m3 756 m3 4758 Bbls WBM – riserless

17.5 (445) 1592 m 247 m3 115 m3 724 Bbls NADF

12.25 (311) 783 m 60 m3 28 m3 174 Bbls NADF

8.5 (216) 360 m 13 m3 8 m3 52 Bbls NADF

JZI-1C 36 (914) 88 m 58 m3153 Mt 390 Mt 315 Mt 101 Mt 32 Mt



17.5 (445) 766 m 119 m3 55 m3 348 Bbls NADF

12.25 (311) 502 m 38 m3 18 m3 112 Bbls NADF

8.5 (216) 330 m 12 m3 8 m3 48 Bbls NADF

JZI-1D 36 (914) 88 m 58 m3153 Mt 390 Mt 576 Mt 136 Mt 27 Mt



17.5 (445) 1401 m 217 m3 101 m3 637 Bbls NADF

12.25 (311) 674 m 51 m3 24 m3 150 Bbls NADF

8.5 (216) 281 m 10 m3 6 m3 41 Bbls NADF

JZI-1E 36 (914) 88 m 58 m3153 Mt 390 Mt 615 Mt 148 Mt 37 Mt



17.5 (445) 1497 m 232 m3 108 m3 681 Bbls NADF

12.25 (311) 733 m 56 m3 26 m3 163 Bbls NADF

8.5 (216) 380 m 14 m3 9 m3 55 Bbls NADF

JZI-1F 36 (914) 88 m 58 m3

153 Mt 390 Mt 335 Mt 97 Mt 32 Mt



17.5 (445) 778 m 126 m3 59 m3 370 Bbls NADF

12.25 (311) 490 m 36 m3 17 m3 107 Bbls NADF

8.5 (216) 351 m 12 m3 8 m3 48 Bbls NADF

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

Table 3-6 Summary of Discharges from Drill Centre 2

Total Weight of Cuttings Generated & Anticipated Material Discharges to Ocean Well Hole Size (inches) Interval

Length Volume of Cuttings

Weight of Cuttings

Anticipated Surface Mud Losses

Mud System

(m) (m3)

JZI-2A 36 (914) 88 m 58 m3153 Mt 390 Mt 389 Mt 110 Mt 32 Mt



17.5 (445) 945 m 147 m3 68 m3 430 Bbls NADF

12.25 (311) 548 m 42 m3 19 m3 122 Bbls NADF

8.5 (216) 334 m 12 m3 8 m3 49 Bbls NADF

JZI-2B 36 (914) 88 m 58 m3153 Mt 390 Mt 664 Mt 178 Mt 33 Mt


26 (660) 430 m 147 m3 756 m3 4758 Bbls WBM - riserless

17.5 (445) 1614 m 250 m3 117 m3 734 Bbls NADF

12.25 (311) 882 m 67 m3 31 m3 196 Bbls NADF

8.5 (216) 345 m 13 m3 8 m3 50 Bbls NADF

JZI-2C 36 (914) 88 m 58 m3153 Mt 390 Mt 399 Mt 113 Mt 26 Mt

48 m3 300 Bbls WBM - riserless


17.5 (445) 971 m 151 m3 70 m3 441 Bbls NADF

12.25 (311) 561 m 43 m3 20 m3 125 Bbls NADF

8.5 (216) 269 m 10 m3 6 m3 39 Bbls NADF

JZI-2D 36 (914) 88 m 58 m3153 Mt 390 Mt 555 Mt 152 Mt 30 Mt



17.5 (445) 1351 m 210 m3 98 m3 614 Bbls NADF

12.25 (311) 756 m 57 m3 27 m3 168 Bbls NADF

8.5 (216) 305 m 11 m3 7 m3 44 Bbls NADF

JZI-2E 36 (914) 88 m 58 m3153 Mt 390 Mt 555 Mt 152 Mt 30 Mt



17.5 (445) 1351 m 210 m3 98 m3 614 Bbls NADF

12.25 (311) 756 m 57 m3 27 m3 168 Bbls NADF

8.5 (216) 305 m 11 m3 7 m3 44 Bbls NADF

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

3.7.5 Cementing Programme

Following is a summary of the cement programme design for the Jansz-Io wells.

The 20” (508mm) surface casing will be cemented to mud line to tie the 20” (508mm) and 36” (914mm) casing together for structural stability.

The 13⅝” (346mm) production casing will be cemented to ~300-525m MD above the 13⅝ “ (346mm) casing shoe, depending on well profile (~40% open hole interval; TOC ~2325m TVD) to provide a pressure seal barrier to shallow formations in the event of a production packer and liner top packer leak during production operations. In addition, leaving ~60% of the open hole interval uncemented will help to ensure that the 20” (508mm) casing shoe is open to relieve annular pressure build-up. Also leaving ~60% of the open hole interval uncemented will enable cutting and pulling the 13⅝” (346mm) production casing to allow side-tracking operations, should that be required during a future well intervention.

The wellbore schematic in Figure 3-4 shows the planned cement program for the Jansz-Io wells.

Figure 3-4 Jansz-Io Cement Programme Design

Mar

l

±2860m TVD±4125m MD

36”

20”

13-5/8”


±1425m TVD/MD

±1850m TVD/MD

±2600m TVD±3200m MD

±2815m TVD±3865m MD

Lim

esto

ne

Silt

sto

ne

& C

lays

ton

eS

and

±1340m W D

Horizontal Tree

Mar

l

±2860m TVD±4125m MD

36”

20”

13-5/8”


±1425m TVD/MD

±1850m TVD/MD

±2600m TVD±3200m MD

±2815m TVD±3865m MD

Lim

esto

ne

Silt

sto

ne

& C

lays

ton

eS

and

±1340m W D

Horizontal Tree

3.7.6 Well Control

The Jansz-Io reservoir completion interval is a single zone and pressured (9.5 ppg equivalents). The previous five exploration/ appraisal wells drilled provide good offset well control for reservoir pressure prediction and there are no plans for deeper appraisal drilling operations.

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

Deepwater development wells with shallow below mudline (BML) reservoir intervals require well completion designs that can handle unplanned leaks/pressure communication without compromising the integrity of the wellbore. The wellbore schematic Figure 3-5 shows the potential well pressures resulting from multiple wellbore equipment failures and the corresponding hole integrity at the 13⅝” (346mm) production casing shoe. The planned setting depth of the 13⅝” (346mm) production casing at 2600 TVDSS provides adequate hole integrity to contain full wellbore pressure at initial producing conditions should multiple equipment failures occur (production packer, tubing leak, liner top packer).

The well’s system of physical barrier is comprised of:

weighted drilling fluids whose hydrostatic pressure exceeds pore pressure;

casings strings that are run in the well that seal off / isolate the formations and formation fluids;

the BOP stack that connects to the wellhead and is tied back to the rig with the marine riser.

Well control criteria barrier requirements include:

A minimum of two physical barriers in each potential flow path;

- At least one barrier must be active at all times.

- A controlled column of fluid that is monitored which has sufficient density to overbalance formation pressures can be one barrier.

Each physical barrier (e.g., cement, plugs, packers, valves, BOPs) shall be pressure tested, preferably in the direction of flow. The pressure test amount shall be greater than the expected maximum expected well pressure at the barrier.

- If testing in the direction of flow is not possible, a pressure test in the opposite direction shall still be conducted.

- If pressure testing is not possible, the integrity of the barrier will be verified through diagnostics and/ or analysis of the operation by which the barrier was installed.

If reducing hydrostatic overbalance below pore pressure is planned and failure of a single physical barrier could cause the well to flow, that barrier will be negatively tested in the direction of flow.

DP rigs shall have two shear rams one of which must be sealing.

Emergency Disconnect System (EDS) function tested prior to deployment of the BOPs

Remote Operated Vehicle (ROV) hot stabs to be surface tested with the ROV pump or equivalent.

Both the Auto-shear and Deadman systems to be surface tested prior to deployment of the BOPs.

Subsea wellhead seal assembly lock down requirements.

Well shut-in procedures. Any changes to operating procedures or conflicts in well control policy including those requested by ExxonMobil shall be managed in accordance with the Transocean Company Management System. In assessing changes to the planned campaign a Management of Change (MoC) process will be followed. This process applies risk assessment to the MoC to ensure the risks associated with any proposed changes are kept to As Low as Reasonably Possible (ALARP).

Any changes to the drilling programme will be updated in the Standing Instructions to Drillers which will then be endorsed by the Deepwater Frontier Vessel Master. Transocean and ExxonMobil agree to consult whenever a change may impact safety or operations on the Mobile Offshore Drilling Unit (MODU).

3.7.7 Dynamic Kill

Dynamic kill simulations of potential uncontrolled gas flows have been conducted for in the purposes of contingency planning for the drilling and production of the 9⅝” “big bore” wells planned for the Jansz-Io development project. Kill simulations for the 26” (660mm) and 171/2” (445mm) hole sections have not been undertaken as there is no risk of encountering hydrocarbons in these sections.

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

A representative profile for a typical Jansz-Io well was used for the modelling, which was a build and hold well to an inclination of 80º. It was assumed the dynamic kills were achieved by pumping down relief well. The worst case scenario was determined to be during drilling with the longest bore conduit. For the drill wells the depth of intersection of the relief well with the flowing well was varied from a depth just below the 13⅝” (346mm) production casing shoe to the top of the producing formation (it was assumed flow was back to the seafloor).

The simulations showed that dynamic kills were achievable for the worst case conditions described above. More specifically, the simulations produced the following results:

For the drill wells with an open hole diameter of 12¼ “ (311mm), mud weight of 18 ppg was successful in producing dynamic kills at reasonable pump rates and total volumes with a single big bore relief well.

For the drill wells with an open hole diameter of 8 1/2” (216mm) by 9 7/8” (251mm) and mud weight of 15ppg were successful in producing a dynamic kill at reasonable pump rates and total volumes with a single big bore relief well.

3.7.8 Completion

The Jansz-Io wells are designed as high rate ‘big bore’ completions utilizing 9⅝” (244mm) (production tubing. Sand control will be installed at initial completion using ExxonMobil’s proprietary alternate path technology (NAFPac) to help ensure a complete gravel pack in the 80º open hole interval. The wellbore schematic in Figure 3-5 shows a typical completion design for the Jansz-Io wells.

Equipment design specifications include permanent down-hole pressure/temperature gauges, down-hole chemical injection mandrel and 7” (178mm) Tubing Retrievable Surface Controlled Subsurface Safety Valve (TR-SCSSV). The TR-SCSSV was specifically designed and qualified for the Jansz-Io programme.

An aqua-linear system is planned as the gravel pack fluid. A Potassium Chloride/ Sodium Bromide solution is planned as the packer fluid.

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

Figure 3-5 Well Bore Schematic

3.7.9 Well Clean-up

The Jansz-Io wells will be cleaned-up using well test equipment on the DWF. Specialist testing equipment will be supplied by the well testing engineering company, Expro. The objective of the clean up is to flow back the under-balance fluid and any fluids lost to the formation during the completion, leaving the well shut-in with gas. This prevents any formation damage during the temporary plug and abandon period, and leaves the well ready for production start-up.

Sand control will be installed at initial completion using ExxonMobil’s proprietary alternate path technology to help ensure a complete gravel pack in the 80o open hole interval.

36” (1.5” wt)~ 1425m MD

Chemical Injection

Pressure / Temp Gauge

7” TR-SCSSV

20”, 133ppf, K-55, MT~ 1890m MD

1885m TVD

13⅝”, 88.2ppf, P-110Vam Top KX~ 3430m MD

2600m TVD

9⅝”, 53.5ppf, 13Cr80,Vam Top KX~ 4286m MD

2845m TVD

FTD ~ 4645m MD2907 m TVD

Gravel Pack Screens5½”, 20ppf, 13Cr80 Basepipe

Formation Isolation Valve ~ 4200m MD(ID=4.56”)

Gravel Pack Packer~ 4130m MD

Anchored Seals w/ re-entry guide & 4.562”No-go nipple~ 4115m MD (ID thru seals=4.75”)

9⅝” Liner Hanger w/ Packer~ 3360m MD

7” TR-SCSSV~ 1800m MDMin ID=5.95”9⅝” x 7” flow cplgsabove/below

Directional Program

Build Rate = 3º/30m

Build/ Hold/ Build Profile

Max Angle = 80º

Tubing9⅝”, 53.5ppf, 13Cr80, Vam Top KX

Gravel PackNAFPac

9⅝” x 7”Production Packer

9⅝” x 7” x-over

9.8

pp

g p

acke

r fl

uid

5.750” No-go nipple

7” SST Tubing Hanger Min ID=6.184” <HOLD>625 clad7” x 9⅝” flow cplg below TH

Tubing7”, 29ppf, 13Cr80 Vam Top HC

Horizontal Tree Mudline ~ 1374m MDRT

36” (1.5” wt)~ 1425m MD

Chemical Injection


7” TR-SCSSV

20”, 133ppf, K-55, MT~ 1890m MD

1885m TVD


2600m TVD


2845m TVD








Directional Program



Max Angle = 80º


Gravel PackNAFPac



9.8

pp

g p

acke

r fl

uid





36” (1.5” wt)~ 1425m MD

Chemical Injection


7” TR-SCSSV

20”, 133ppf, K-55, MT~ 1890m MD

1885m TVD


2600m TVD


2845m TVD








Directional Program



Max Angle = 80º


Gravel PackNAFPac



9.8

pp

g p

acke

r fl

uid





G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

Analysis modelling has been performed to determine the minimum flow rate needed for effective clean-up of open hole completion interval during the initial flow-back/well testing operations. The analysis of the wells concluded that a rate of 55 Mscfd can adequately clean up the completion interval and remove all particles and fluid out of the wellbore. The maximum anticipated testing rate for well clean-up operations from the drilling rig is estimated to be 100 Mscfd.

The gas composition is known, as formation samples were obtained from Jansz 1, 2, 3 and 4 wells. The entire well-stream will be flared (100% combustion is anticipated based on composition of the gas).

All work will be undertaken as required under the Offshore Petroleum and Greenhouse Gas Storage (Resource Management and Administration) Regulations, 2011.

3.7.10 Logging While Drilling and Wireline Logging

Logging while drilling (LWD) and wireline logging will be carried out, using radioactive sources. However these sources are not unusual and will be subject to normal Transocean and specialist contractor controls.

3.7.11 Drilling Support

Support Vessels Drilling operations will be supported utilising at least two supply vessels, the Maersk Nexus and Maersk Nomad, operating out of the Port of Dampier. These vessels may be changed during the campaign depending on availability.

In addition a Fast Supply and Intervention Vessel (FSIV) vessel, the P&O, FOS Polaris (or similar vessel), will be used during the campaign and has dispersant application capabilities. Vessel specifications are outlined in Table 3-7.

Table 3-7 Support Vessel Specifications

Vessel Specification

Maersk Nexus

(or similar)

Lloyd’s Register +100A1, +LMC, UMS, ICE 1C, SCM, DP (AA). IWS, EP (GNPR), Oil Recovery Ship Fire Fighting Ship 1 (2,400 m3/hr), Canadian standby vessel for 360 persons.

Maersk Nomad

(or similar)

Lloyd’s Register +100A1, +LMC, UMS, ICE 1C FS, SCM, DP (AA). IWS, EP (GNPR), Oil Recovery Ship Fire Fighting Ship 1 (2,400 m3/hr), Canadian standby vessel for 300 persons.

The FOS Polaris

(or similar)

ABS + A1 (E) HSC, +AMS, +DPS-1, Towing Service, FIFI 1 (Fire Fighting Capability), Safety Standby Service GB B-(60), ERRV Class B.

These vessels will be used to move bulk and liquid materials, equipment and containers between the Dampier shore base and the Transocean DWF whilst it is at the Jansz-Io location. The vessels will be used for:

supply operations;

emergency response and rescue;

assist with shipping monitoring and maintaining the 500m exclusion zone around the MODU.

Installation of subsea horizontal trees

While on location the vessels will also perform collision watch duties. All vessels are capable of providing standby duties for 300 persons.

The support vessels will be equipped with vessel identification and communication systems designed to lower the risk of collision. Whilst these vessels are on location they are able to maintain radar watch and shall contact all vessels coming within a 10 nm point of approach to the DWF. These vessels are specifically designed for use within the offshore petroleum industry and are operated by crews familiar with offshore MODU operations. All support vessels have International Maritime Safety (IMS) accreditation. They carry adequate life saving and safety equipment on board to transport personnel from the DFW should the need arise. Each vessel has one hospital berth.

The DWF and support vessels will be operated in accordance with standard industry practice as follows:

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

Bunkering activities associated with the support vessels to be undertaken at shore-based refuelling facilities such as at Port of Dampier.

The onboard sewage treatment system to treat all sewage and grey water prior to discharge.

All solid non-putrescible wastes to be disposed of via mainland facilities.

Vessel oily water separators to capture contaminated water from potentially contaminated work areas.

Seawater used to cool freshwater in enclosed recirculating heat exchange systems to be discharged continuously during drilling.

Flaring during well clean-up will be conducted around the clock as required (subject to separate regulatory approval).

Vessel mobilisation and demobilisation to comply with all AQIS requirements with respect to ballast water, hull fouling and quarantine waste management as required.

Helicopter Support Helicopter support will be based at Barrow Island, about 140 km from the drilling activity. Bristow will utilise Eurocopter EC225 helicopters, these are twin engine, two pilot operated aircraft.

The Eurocopter aircraft is within the design criteria of the Transocean DWF Helideck which is stated as being designed for the Sikorsky S-61 or Super Puma 322L helicopter.

Helicopter operations will be performed in accordance with Civil Aviation Safety Authority (CASA) regulations. Helicopter type, suitability, and performance criteria are contractually controlled, as is minimum flight and engineering crew qualifications and experience levels.

Arrangements have been made with Bristow to ensure that a helicopter is available at all times (inclusive of night flights), for the purpose of conducting emergency evacuations and Medivac. Three EC 225 helicopters will be available on Barrow Island. These are a new generation, with 19 seat configuration.

Refuelling may take place on the Transocean DWF as part of the Jansz-Io campaign. Facilities and procedures exist for helicopter refuelling. Standard risk management practices and training will apply to the management of these activities. The helifuel system complies with the requirements of IMO MODU Code 1989, ABS Class Rules and UK CAA CAP 437.

Distances and travelling times between the Jansz-Io field, Dampier supply base and Barrow Island airbase are summarised in Table 3-8.

Table 3-8 Jansz-Io Field Proximity and Travel Time

Destination / Point of Origin Kilometres Nautical miles

Travel Time

Barrow Island to Jansz-Io field (by helicopter) 154 83 ~ 45 mins (each way)

Jansz-Io field to Karratha (by helicopter) 246 133 ~ 70 – 90 mins (each way)

Jansz-Io field to Dampier (by vessel) 239 129 ~7 hrs (@ 20 knots)

~13 hrs (@10m knots) Note: 1 knot = 1.852 km per hour. 1.852 km = 1 nautical mile (nm).

Pipelines Pipeline/flow-line installation is not within the scope of this EP as this scope of works will be managed by Chevron Australia as the Jansz-Io Unit Operator.

Diving No diving operations are anticipated and no diving equipment has been contracted for the operation.

ROV A remote operated vehicle (ROV) will be used during the drilling campaign. The ROV will be skid mounted, and located on the rig. It will be used for pre drilling seabed inspections, to detect any potential for shallow gas while drilling and setting the conductor and 20” (508mm) casing, periodic seabed inspections whilst drilling and for final seabed surveillance prior to departing from location. The ROV will be operated by specialist ROV contractors. In addition an ROV will be available on one of the Supply vessels.

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

3.8 Drilling Safety

Drilling of previous exploration wells in the permit area has provided substantial information on the nature and stability of the seabed and underlying strata. The positioning and operation of the drill rig will be closely supervised by the Drilling Contractor’s (Transocean) marine personnel and the ExxonMobil Drilling Supervisor on-board the MODU.

During the drilling programme, a temporary safety exclusion zone with a radius of 500 m around the drill rig will be declared in accordance with section 329 of the OPPGSA 2006 and appropriately gazetted. Few vessels are expected to be operating in the area, but those that do will be informed of the location of the drill rig and the exclusion zone by radio.

The wells are designed and engineered as described in section 3.6 above to approved standards to ensure that well pressures remain within the safety limits. The high specification drill rig’s blowout preventer (BOP) equipment is capable of containing the anticipated formation pressures.

Casing specifications, setting depths and a cementation programme have been selected to maximise well control. Experience gained with previous exploration wells drilled in permits WA-18-R, WA-25-R, WA-26-R and surrounds have been taken into consideration in the well design.

An Emergency Response Plan (ERP) [Ref 31] and an Oil Spill Contingency Plan (OSCP) detailing actions to be taken in the event of an emergency or oil spill have been prepared to support the Jansz-Io drilling activities [Ref 30].

Prior to commencement of operations, an induction programme will be held for relevant personnel from Transocean, ExxonMobil and service companies. An overview of the ERP and OSCP will be included in the project induction, with additional training for those personnel with specific responsibilities.

3.9 Shallow Gas

A shallow gas assessment from the 3D seismic near-angle seismic traverse through the proposed Jansz-Io locations at drill centres 1 and 2 shows the following with respect to shallow has hazards:

Seafloor is slightly rugose (wrinkled) in the general vicinity, but essentially flat at the well location, dipping less than 0.5o to the north.

There is a low probability of low velocity, low sediment volume, turbidite flows on the seabed.

In the nearest offsets, Jansz-3 and Jansz-4, conductor casing was jetted to total depth with no shallow gas issues.

Shallow gas has not been observed in either well and it is not anticipated in the top-hole sections at Jansz-Io.

There have been no significant problems reported in the offset wells while drilling the top-hole section.

The shallow section is normally pressured; abnormal pressure is not anticipated at the Jansz-Io location.

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

4 EXISTING ENVIRONMENT

4.1 Physical Environment

The Jansz-Io field is located in Commonwealth waters on Australia’s North West Shelf, approximately 250 km west-northwest of Dampier within Licence areas WA-36-L, WA-39-L, and WA-40-L. The Jansz-Io gas field lies beyond the Continental Slope, on the western flank of the Kangaroo Syncline in water depth of approximately 1300 m. The water depth of the Jansz-Io wells is approximately 1340 m (Figure 1-1). The seabed is predominately flat and featureless with a gentle slope towards the northeast of less than half a degree at the well locations.

Approximately 1 to 2 km northeast and east of the proposed well locations, the basin-ward extent of recent turbidity flows is easily observed. These features have local dips in excess of 5 degrees and relief of up to 10 m. Seafloor sediments are very soft, carbonate clays. Near-surface soils consist of approximately 5 m of very soft, sandy clay lying atop a 163 meter thick debris flow made up of carbonate clasts, sands and clays.

4.1.1 Temperatures

The Bureau of Meteorology [Ref 14] records for Barrow Island which is approximately 154 km from the Jansz-Io wells show that mean daily maximum summer temperatures range from 33°C to 35°C with the highest maximum temperature recorded 45°C. Mean daily maximum winter temperatures ranges from 25°C to 26°C. Offshore temperatures in the permit area are likely to be less extreme.

Mean monthly rainfall ranges from 12 mm to 55 mm in summer with the highest mean monthly rainfall of 65 mm occurring in June. The highest daily rainfall of 193 mm was recorded in the month of December and almost certainly was due to a cyclonic storm.

4.1.2 Seawater Temperature

The seawater in the Jansz-Io area is strongly thermally stratified throughout the year and has a permanent and extensive thermal gradient that is the highest from around the 100-220m depth, but will continue to persist too as deep as 500m. The near-surface seawater will attain a maximum temperature of 30 – 31oC by late summer (February – April) and cooling to a minimum 22 – 23oC by late winter (August – October). The temperature difference between surface and the bottom is approximately 27oC in the summer and 19oC in the winter. The seafloor water temperature will remain fairly constant throughout the year at 4o C.

4.1.3 Tides

Astronomical tides on the NWS are semidiurnal and generally quite large, ranging from 0.95 m near Exmouth to more than 3 m on the inner shelf near Broome. Maximum spring tide amplitudes range from just over 2 m at Exmouth, 2.5 m at Onslow, 4.5 m at Dampier to nearly 6 m at Port Hedland. The increase in tidal amplitude from south to north is most marked north of the Montebello Islands, where the width of the continental shelf increases significantly [Ref 36].

4.1.4 Winds and Waves

The climate is monsoonal with seasonal winds primarily from the south-southwest during the summer and transitional spring months and rarely from the north-west or north. During winter, the winds typically prevail from the easterly and south-easterly direction and remain rare from the north-west or north. During the transitional autumn and spring months, the winds swing between the summer and winter patterns and southerly winds are quite common. Figure 4-1 shows the monthly distribution of wind direction as derived from the nearest data location (coordinates 20° S, 115° E) sourced from the National Centre for Environmental Predictions (NCEP) [Ref 46].

Of the five significant storm types which occur in the area (tropical cyclones, monsoonal surge, squalls, trade wind surge and tornadoes), tropical cyclones are clearly the most important for extreme wind design criteria (except for deeper layer currents which are dominated by tidal forces). Tropical cyclones originate from south of the equator in the eastern Indian Ocean and in the Timor/Arafura Seas during the summer months of November to May. Historical analysis indicates that on average about 1.4 cyclones should pass within 200km and about 4.9 cyclones pass within 1000km of the Jansz-Io site each year.

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

Tables 4-1 to 4-6 provide wind, wave and current data from a study on metocean criteria for the Jansz-Io location [Ref 45].

Table 4-1 Wave Dominant (non-cyclonic) Return Period – Summer (Oct to Mar)

Return Period Hs(m) Tp(s) Associated 1-hour Wind Speed (m/s)

Associated Surface Current (cm/s)

95% 3.3 9.0/ 16.0 10.4 40

1-year 4.3 10.0/ 17.7 13.2 80

5-year 4.7 10.3/ 18.0 14.0 90

10-year 4.8 10.4/ 18.0 14.2 90

100-year 5.0 10.7/ 18.5 14.6 110

Table 4-2 Wave Dominant (non-cyclonic) Return Period – Winter (Jun – Aug)



95% 3.5 9.0/ 15.0 9.0 40

1-year 4.5 9.9/ 15.0 14.4 80

5-year 5.1 10.6/ 16.0 16.0 90

10-year 5.3 11.0/ 16.5 16.5 90

100-year 6.1 12.3/ 17.0 18.3 110

Table 4-3 Wave Dominant (non-cyclonic) Return Period – Transition Period (Sep/ Apr / May)



95% 3.5 9.0/ 15.0 9.2 40

1-year 4.0 9.5/ 15.0 10.1 80

5-year 4.5 9.9/ 15.0 11.0 90

10-year 4.7 10.1/ 15.0 11.4 90

100-year 5.4 11.3/ 16.5 12.6 110

Table 4-4 Wind Dominant (non-cyclonic) Return Period – Summer (Oct to Mar)

Return Period 1-hour Wind Speed (m/s)

Tp(s) Hs(m) Associated Surface Current (cm/s)

95% 10.7 8.0/ 16.0 2.9 40

1-year 15.3 9.9/ 17.5 4.2 80

5-year 16.2 10.0/ 17.7 4.3 90

10-year 16.4 10.0/ 17.7 4.4 90

100-year 17.3 10.2/ 17.9 4.6 110

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

Table 4-5 Wind Dominant (non-cyclonic) Return Period – Winter (Jun to Aug)



95% 10.9 7.7/ 15.0 3.5 40

1-year 15.3 9.7/ 15.0 4.2 80

5-year 16.6 10.0/ 15.0 4.6 90

10-year 17.0 10.4/ 16.0 4.9 90

100-year 18.4 11.5/ 16.5 5.5 110

Table 4-6 Wind Dominant (non-cyclonic) Return Period – Transition Period (Sep/ Apr/ May)



95% 10.4 8.0/ 15.0 2.9 40

1-year 14.4 9.6/ 15.0 3.8 80

5-year 15.6 9.7/ 15.0 4.2 90

10-year 16.0 9.8/ 15.0 4.3 90

100-year 17.3 10.4/ 15.0 4.8 110

The total wave climate is composed of locally generated wind waves, the direction of which follows that of the prevailing winds (SW in summer / SE in winter), and the perennial swell propagating into the area from distant regions to the SW. Southern Ocean storms may generate very long period swell (16 – 21 sec), which arrive in the Jansz-Io area from the SW with a typical mean annual amplitude of about 1.5m.

Tropical cyclones and strong synoptic easterly winds over extensive fetches to the NW of the location may generate shorter period swell (6-10 sec), which arrives at the location from ENE. Tropical cyclone swell may attain maximum heights of 5-10m during severe events.

Excluding cyclones, summer total sea states prevail from the SSW and SW. The ample available fetch results in typical mean summer total significant wave heights of about 2.1m (mean period of 12 sec).

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

Figure 4-1 Wind Direction

4.1.5 Currents

The currents in the Jansz-Io area are dominated by tidal forcing. Local winds and oceanic drift (Leeuwin Current) can be important at times and more so in the upper 200m of the water column.

Maximum non-cyclonic current speeds in upper regions (surface to 100m) will likely range from 0.33 – 0.8 m/sec in the Jansz area. Maximum cyclone current speeds (surface to 100m) may occasionally approach 0.5 – 1.1 m/sec under extreme storm conditions.

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

4.2 Benthic Species

4.2.1 General

In 1999, an ROV survey of the seafloor at WA-267-P was undertaken, which revealed fine grained cohesive sediments which are variously bio-turbated, indicating the presence of a range of in-faunal organisms [Ref 8]. Isolated larger fauna observed comprised a free swimming cnidarian, two demersal fish and a few benthic crustaceans (scampi) [Ref 8]. Environmental sampling undertaken by ExxonMobil in conjunction with a pipeline survey, and geotechnical and geophysical studies in May 2005 confirmed that benthic fauna in the Jansz-Io region are generally depauperate and typical of the low abundances, richness and diversity observed in other deep areas of the NWS [Ref 39].

4.2.2 In-fauna

Benthic fauna in the Jansz-Io region, like other deep areas of the NWS, is depauperate, with low abundances, richness and diversity. Infaunal communities in the region appear to be most influenced by water depth and sediment size. Generally there is lower energy in deeper water that can disturb sediments which are usually finer grained sands and silts with varying proportions of mud and shell fragments. This creates habitats suitable for burrowing organisms, particularly polychaete worms and smaller crustaceans.

This is consistent with regional sampling studies of the benthos over similar substrate and at similar depths [Ref 49, 55 and 57] which recorded low densities of benthic in-fauna dominated by mobile burrowing species, including molluscs, crustaceans and (polychaete, sipunculid and platyhelminth) worms [Ref 15].

Absence of hard substrate is considered a limiting factor for the recruitment of epibenthic organisms. Light penetration to the bottom at depths of 1,300 m is considered insufficient for the development of plants (seagrasses and algae) and scleractinian (reef building) corals.

A survey was conducted of the Jansz pipeline route taking environmental samples to obtain data on benthic fauna and habitats [Ref 39]. Benthic surveying at 18 sites, predominantly along the most likely pipeline route, revealed that benthic fauna in the region is depauperate. No epibenthic fauna were recorded from the majority of samples and infauna, when present, were in low abundance with low richness and diversity. Infaunal composition was very similar at the majority of sites. Significant relationships were evident between water depth and infaunal abundance, richness and diversity and there was a correlation between sediment properties and community similarity between sites. In general, abundance, richness and diversity decreased with increasing water depth. Grain size parameters, particularly larger grain sizes, also appeared to influence infaunal communities.

The depauperate benthic fauna in the Jansz region is typical of the low abundances, richness and diversity observed in other deep areas of the North West Shelf. The deep water, fine sediments and associated depauperate fauna occurring around the proposed drill site means that the risk of impacting benthic faunal communities is very low.

4.2.3 Coral reefs

The nearest coral reefs are more than 120 km away to the east southeast at the Montebello Islands. Coral reefs and coral-dominated benthic communities are common in rocky shallow water areas. The most common morphology of these reefs is a fringing formation adjacent to mainland rocky shores or emergent islands. The Ningaloo Reef tract approximately 330 km to the east southeast and extending further southward from the North West Cape is Australia’s major fringing reef system and is managed as a Marine Reserve. Detailed taxonomic surveys on shallow water coral reefs in the region typically report high biodiversity and fine-scale habitat complexity [Ref 36]. Coral spawning peaks between March and April and usually occurs 7–10 nights after the full moon.

The water depth at the Jansz-Io area precludes any significant habitat for coral.

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

4.3 Sea snakes

The seas of tropical Australia support a rich sea snake fauna, with a strong endemic component and have greater species diversity than any other region. Of the world total of approximately 55 species, 32 species are recorded from tropical Australia, and nearly 50% of these are endemic [Ref 19]. In all 16 species have been recorded on the North West Shelf and surrounding region with another 7 presumed to occur.

Sea snakes are air-breathing reptiles, and most have shallow benthic feeding patterns. Observations would indicate that most sea snakes are found in depths rarely exceeding 30 metres [Ref 19]. Some species are known to dive deeper than this, but it can be concluded that non-pelagic species seldom, if ever, dive deeper than 100 m [Ref 34 and 35].

The Pelamis platurus (yellow-bellied sea-snake) or its habitat may occur within the region but mostly in the shallower water locations described above. The Hydrophis elegans (elegant sea-snake), Aipysurus laevis (olive sea-snake) or their habitats may also occur within the region, however, the water depth and lack of suitable habitat would preclude this species. The most common foraging strategy employed by sea snakes is ‘crevice foraging’, followed by ‘bottom cruising’ [Ref 35].

4.4 Turtles

Based on a search of the Department of Sustainability, Environment, Water, Population and Communities (SEWPAC) EPBC Act Online Protected Matters Database [Ref 51], five species of marine turtles or their respective habitats may occur in the region of the Jansz-Io drilling. These are as follows:

Scientific Name Common Name

Dermochelys coriacea Leatherback (or Leathery) turtle

Chelonia mydas Green turtle

Natator depressus Flat-back turtle

Eretmochelys imbricate Hawksbill Turtle

Caretta caretta Loggerhead Turtle

Under the EPBC Act the Leatherback and Loggerhead are listed as endangered and the Green, Flat-back and Hawksbill turtles are listed as vulnerable. All these turtle species are listed as migratory species under the EPBC Act and also under the Convention of Migratory Species (CMS) (Bonn Convention) with the exception of the Flatback turtle.

Apart from when turtles are nesting and ashore, turtles are oceanic. Nesting is generally confined to specific nesting sites. On the north-west shelf region of Western Australia nesting (depending on species) generally occurs from September to April [Ref 48]. The nearest marine turtle nesting ground to the Jansz-Io drilling area is on the west coast of Barrow Island, approximately 140km from the nearest drill centre. Nesting of turtles also occurs on other islands in the region and along the mainland coast from the Kimberly Coast through to Shark Bay in the south. All the turtle species shown above have known nesting sites in Western Australia except for the Leatherback turtle. Leatherback turtle nesting is known to have occurred in the Northern Territory.

The green turtles are herbivores, feeding on macro-algae and seagrass beds in shallow waters. Flat-back turtles are carnivorous, foraging often around coral reefs. Loggerhead Turtles are also carnivorous, feeding primarily on benthic invertebrates in habitat ranging from near-shore to 55 m.

The Leatherback is the most pelagic of all the marine turtles and mostly feeds on gelatinous organisms such as jellyfish.

Given the water depth at the Jansz-Io drilling location (approximately 1340 m) it is unlikely that marine turtles will feed in the area, however, as migratory species, they may pass through the area as they migrate from foraging to breeding locations. For the full EPBC Act Protected Matters Report for the Jansz-Io region refer Appendix 4.

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

4.5 Mammals

Two threatened mammal species or their respective habitats may occur in the region of the Jansz-Io drilling. These are Humpback whale (listed as vulnerable) and the Blue whale (listed as endangered).

The Humpback whales have two migratory routes around Australia from the Antarctic feeding grounds to the warmer breeding grounds in the tropic and sub-tropic waters off the Australian coastline (one on the east and one on the west). The peak migratory period for the west coast population is mid to late July for the northward migration and late August to mid September for the southward migration in the Pilbara region. The whales tend to migrate in water depths of 20 m to 500 m with the majority of whales within the 50 m to 200 m isobaths based on SEWPAC whale sighting reports over recent years. The Jansz-Io well area is located in water depths of approximately 1340 m. Humpback whales mate and breed in inshore waters off the Kimberley coastline. The closest aggregation point to the Jansz-Io drilling location for Humpback whales is the Exmouth Gulf over 250 km away where the sheltered waters are used as resting sites, predominantly for cow-calf pairs on the southern migration [Ref 22].

Blue whales sightings are widespread in Australian waters. However there are no known breeding areas on the west coast of Australia. Aggregation spots for this species are focused around known feeding grounds, of which the closest to the Jansz-Io drilling region is the Perth Canyon (located approximately 22 km from Rottenest Island and over 1000km from Jansz). Blue whales feed off the krill in this region which occur at depths of up to 500 m during the day and rise to the surface by night. Blue whales can be subject to vessel strike if feeding at the surface however as the Perth Canyon is over 1300 km away this is not a credible risk during the Jansz-Io drilling [Ref 23]. Figure 4-2 shows the whale migration paths around Australia.

Based on a search of the SEWPAC EPBC Act Online Protected Matters Database [Ref 51], other migratory cetaceans of national significance that may be encountered within the Jansz-Io region are the Antarctic Minke and, Dark-shoulder Minke Whale, Bryde’s Whale, Killer Whale and the Sperm Whale. These species are not listed as threatened. Of these, there are known habitats in Western Australia for the Bryde’s Whale to the north of Shark Bay and near the Abrohlos Islands, the closest of which is over 600 km from the Jansz-Io region. Further south in Cape Leeuwin there are known habitats for the Sperm Whales.

There are no known areas of importance for these species, either breeding or feeding, around the Jansz-Io region however as all are migratory, they may occasionally be encountered passing through the region [Ref 51]. All species discussed in this section and other cetaceans of national environmental significance which may be found in the region are listed in Table 4-7.

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

Table 4-7 Cetaceans of national environmental significance that may occur in the Jansz-Io well area

Category Species Common Name Status

Migratory Cetaceans

Balaenoptera musculus Blue Whale T, E, M

Megaptera novaeangliae Humpback Whale T, V, M

Balaenoptera bonaerensis Antarctic Minke Whale, Dark-shoulder Minke Whale

M

Balaenoptera edeni Bryde’s Whale M

Orcinus orca Killer Whale M

Physeter macrocephalus Sperm Whale M

Other Cetaceans

Feresa attenuata Pygmy Killer Whale

Globicephala macrorhynchus Short-finned Pilot Whale

Peponocephala electra Melon-headed Whale

Kogia breviceps Pygmy Sperm Whale

Kogia simus Dwarf Sperm Whale

Mesoplodon densirostris Blainville’s Beaked Whale, Dense-beaked Whale

Ziphius cavirostris Cuvier’s Beaked Whale, Goose-beaked Whale

Pseudorca crassidens False Killer Whale

Delphinus delphis Common Dolphin

Stenella coeruleoalba Striped Dolphin, Euphrosyne Dolphin

Stenella attenuata Spotted Dolphin, Pantropical Spotted Dolphin

Lagenodelphis hosei Fraser’s Dolphin

Steno bredanensis Rough-toothed Dolphin

Stenella longirostris Long-snouted Spinner Dolphin

Grampus griseus Risso’s Dolphin

Tursiops truncatus s. str Bottlenose Dolphin

Status Key: E–Endangered (threatened) / V–Vulnerable (threatened) / M-Migratory marine species / T - Threatened

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

Figure 4-2 Whale Migration Paths (DEWHA, 2006)

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

4.6 Seabirds

The nearest significant seabird nesting areas to the Jansz-Io location are Barrow and Montebello Islands over 140 km to the east southeast. The seabird assemblage of the Montebello/Barrow islands region comprises at least 67 species, including 25 species of migratory shorebirds and 20 resident shorebirds with key aspects listed below [Ref 20]. The foraging range of seabirds is uncertain however given the distance of the Jansz-Io region to any land, if they are found it is unlikely that they will be in significant numbers.

A significant number of migratory birds that pass through the NWS region are listed on one or both of the China Australia Migratory Bird Agreement (CAMBA) and Japan Australia Migratory Bird Agreement (JAMBA). A search of the SEWPAC EPBC Act Database did not identify any species of concern within the Jansz-Io well area.

4.7 Fish

4.7.1 General

In general, the fish offshore of north-western Australia are typical of the Indo-Pacific region. Seas encompassing northern Australia and the tropics that lie immediately northward are inhabited by the richest fish fauna on earth [Ref 1]. Official counts are lacking, but an estimated 4,000 species occur in the region, or about 30% of the world’s total marine fishes [Ref 1]. The dominant groups across this region usually include such families as gobies, wrasses, damselfishes, gropers, moray eels, cardinal fishes, and surgeonfishes [Ref 1].

4.7.2 Invertebrates

The major groups of invertebrates that are likely to be present are shown in Table 4-8 [Ref 41]. However the majority of species listed are located in much shallower waters east of the Jansz-Io well area.

Table 4-8 Invertebrates likely to be found near the Jansz-Io well area

Common name Spawning Period

Habitat Depth Range (m)

Resource Status

Type of Fishery

Fishing method or gear

Inshore Squid and Calamari

All Year Neritic, Oceanic

<300 U C, R Jigging, nets

Tiger Prawn All Year Neritic, Reefs 0-200 F C Nets

Royal Red Prawn Summer-Winter Oceanic > 230 Uncertain C Nets

Giant Tiger Prawn Spring, Autumn Neritic <110 Unknown C Nets, pond, culture

Western Rock Lobster

Winter-Summer Neritic, Reefs 1-200 F C, R Traps

Ornate Rock Lobster

Spring-Autumn Neritic, Reefs 1-200 F C,R Traps

Source: (Kailola et al, 1993) Key: R – Recreational, C – Commercial Resource Status: U - Under-exploited, H - Heavily exploited, O - Over exploited, F - Fully exploited.

4.7.3 Oceanic Fishes

The major groups of oceanic fishes likely to be found near the Jansz-Io well area are shown in Table 4-9 [Ref 41, 25]. However the majority of species listed are located in much shallower waters east of the Jansz-Io well area.

The search of the SEWPAC EPBC Act Database did not identify any fishes as there is no suitable habitat in the deeper waters where the drilling will take place. However, two sea-snakes were identified (refer to Section 4.3).

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

4.7.4 Sharks

The Longfin Mako Shark and the Shortfin Mako Shark are the only shark species in the SEWPAC EPBC Online Protected Matters Database Report for the Jansz-Io region that are listed as likely to occur in the region. These species are widely distributed, highly migratory tropical, oceanic sharks which have extensive habitats. They have a large depth range and have also been seen on the surface however they are rarely encountered. The biggest threat to these species is longline or driftnet fishing where they are caught as bycatch [Ref 16]. The Longfin Mako is found in the northern Australian waters whereas the Shortfin Mako is found in waters all around Australia.

Whale sharks are the largest living fish and can reach a length of 12m. Whale sharks feed on a wide variety of planktonic and nektonic prey, including small crustaceans, small schooling fishes, and occasionally on tuna and squid [Ref 42]. They occur worldwide in tropical and temperate seas, near the coast and in the open oceans.

Sea temperatures in the 21-250C range, in the vicinity of cold water up-wellings, are preferred because these conditions are probably optimal for their prey. Their movements are thought to be related to local productivity and are often related to schools of pelagic fish [Ref 42].

They are highly migratory and small aggregations occur near the coast of central Western Australia each autumn particularly off Ningaloo Reef in March and April [Ref 42 and 18]. Their appearance coincides with coral spawning and the associated rise in productivity. The drilling area is approximately 330 km west northwest of Ningaloo Reef. While a search of the SEWPAC EPBC Act Database did not identify this species, it can potentially occur within the Jansz-Io region.

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

Table 4-9 Oceanic Fishes

Common name (species #)

Spawning Period Habitat Depth Range (m)

Resource Status

Type of Fishery

Fishing Gear

Dusky and Bronze whalers

Summer Neritic, Oceanic 0-400 Unknown C,R lines, nets

Dories (2) Summer - winter (S) Neritic, oceanic 5-800 (S) Unknown C,R lines, nets

Oreos (4) Winter - spring (S) Oceanic 200-1600 (S) Unknown C Nets

Sea mullet Autumn - winter (L) Neritic, Freshwater, Estuarine

Unknown Unknown C,R Lines, nets

Skipjack tuna All year Neritic, Oceanic 0-260 Unknown C,R Lines, nets

Albacore Summer Oceanic 50-500 Uncertain C,R Lines

Yellowfin tuna All year (L) Neritic, Oceanic 0-250 Uncertain B,C,R Lines, nets

Southern Bluefin tuna Spring - summer Oceanic Unknown Uncertain C,R Lines

Big- eye tuna Summer Oceanic 150-250 Unknown B,C Lines

Black marlin Spring - summer Neritic, Oceanic Unknown Uncertain B,R Lines

Blue marlin Summer Oceanic Unknown 0 B,R Lines, nets

Striped Marlin Spring - summer Oceanic Unknown Unknown C,R Lines

Broadbill swordfish Spring - summer Oceanic <600 Uncertain B,C,R Lines

Coral Trout (3) Spring - summer Neritic, Reefs 0-100 H C,R Lines, nets, traps

Rock Cod (3) All year Estuarine, Neritic, Reefs

2-200 0 C,R Lines, nets, traps

Westralian jewfish Summer Neritic, Reefs 20-200 Unknown C,R Lines, nets

Mackerel (4) Variable Neritic 0-100 Unknown C,R Lines, nets

Sea perch (3) Spring - autumn Neritic, Reefs 5-180 U C,R Lines, nets, traps

Tropical snappers (2) Spring - summer (L) Neritic 40-200 Unknown C Lines, nets, traps

Emperors (4) Variable (L,S) Neritic, Reefs 2-90 Unknown C,R Lines, nets, traps

Snapper Winter - summer(L) Neritic, Reefs 1-200 F C,R Lines, nets, traps

Sea mullet Autumn - winter (L) Neritic, Freshwater, Estuarine

Unknown Unknown C,R Lines, nets

Tropical Sharks (2) Summer Neritic <150 Unknown C,R Lines, nets

KEY: S = variation between species is known, L = variation between localities is known. Type of Fishery: C – Commercial, R- Recreational, B – By catch. Resource Status: U - Under-exploited, H - Heavily exploited, O - Over exploited, F - Fully exploited.

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

4.8 Conservation and Heritage Status

4.8.1 National Estate

The nearest National Estate sites to the Jansz-Io region are listed below and are all more than 140 km away.

Islands of Exmouth Gulf and Rowley Shoals.

Muiron Island and surrounds.

Ningaloo Marine Park and Area.

Barrow Island Marine Area (including Monte Bello and Lowendal Island groups).

Coastal Margin Exmouth Gulf to Cape Preston.

Coastal Islands Mary Anne to Regnard.

4.8.2 Conservation and Heritage Status

The proposed drilling area does not lie near or overlap any area having conservation status. Coastal islands reserved such as Marine Parks, Nature Reserves or Conservation Parks (i.e. Barrow, Lowendal and Montebello Islands) and associated marine parks are more than 130 km away from the nearest permit boundary. Ningaloo Marine Park is approximately 330 km from the Jansz-Io well. In addition, there are no known Aboriginal or European heritage or archaeological sites of significance, shipwrecks or heritage sites in the vicinity of the Jansz-Io well area.

4.8.3 Endangered or Vulnerable Species

The EPBC Act Protected Matters Report for the Jansz-Io region identified endangered or vulnerable turtles and marine mammal species which may occur in the Jansz-Io region. Turtles are discussed in Section 4.4 and marine mammals are discussed in Section 4.5.

4.9 Social Environment

4.9.1 Commercial Fisheries

Four commercial fisheries are found in the region, although most fishing is restricted to waters shallower than those in the permit area. Information on these fisheries is summarised in Table 4-10 below [Ref 12].

4.9.2 Tourism and Recreational Fishing

Given the distance offshore, tourism and recreational fishing in the vicinity of the Jansz-Io well area is unlikely. Commercial fisheries in Commonwealth waters are discussed in Table 4-10.

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

Table 4-10 Commercial Fisheries in Commonwealth Waters

Fishery Description

North-west slope Trawl

The North West Slope Trawl Fishery (NWSTF) extends from 114°E to about 125°E off the Western Australian coast between the 200 m isobath and the outer limit of the Australian Fishing Zone. Fishing is conducted with demersal crustacean trawls during the day and night along bathometric contours depending upon the target species sought.

Principal species are:

Scampi: Australiensis scampi, velvet scampi and boschmai scampi:

Deepwater prawns (penaeid and carid): pink prawn, red prawn, striped prawn, scarlet prawn, red carid and white carid prawn.

Western Deepwater Trawl

The Western Deepwater Trawl Fishery (WDWT) is located in deep water off Western Australia, from the 200m isobath to the edge of the Australian Fishing Zone (AFZ). Its northern most point is the boundary of the AFZ to longitude 114° E and southern most point at the boundary of the AFZ to longitude 115° 08’E. The Ningaloo Marine Park extends into the area of the Fishery and the northern part of the Fishery is also an area of high oil and gas productivity. Fishing method is demersal fish trawl.

Principally a finfish trawl fishery, species diversity is considerable. Commercial species are taken onthe upper (200-700 m) and mid-continental slope, but generally not in large quantities. The community structure in the WDWT Fishery ranges from a temperate/sub-tropical fish community in the south, to a more tropical fish community at the northern range of the Fishery. A wide range of species are caught, ranging from tropical snappers on the shelf edge to orange roughy, oreo dories and bugs in the deeper temperate waters.

Skipjack Tuna (Western)

Skipjack tuna are widely distributed throughout tropical waters of the Indian and Pacific Oceans.

The Australian Fishing Zone (AFZ) is at the extreme southern end of their range. Skipjack distribution in the AFZ on the east coast is from far north Queensland to Tasmania, excluding the Great Barrier Reef, off southern Australia from Kangaroo Island in the Great Australian Bight, and up the west coast to Broome. Skipjack tuna (Katsuwonus pelamis) is the only target species in the fishery. The landings of species other than skipjack (may include bigeye and yellowfin tuna, frigate mackerel, sharks, mahi mahi, rays and marlins) are believed to be much less than 2% of the total landings. Up until 1998 purse seine accounted for around 85% of the total skipjack catch, pole and line for 14%, and long-line and minor line methods for the remainder. Since 1999 the pole catch has decreased representing only 1% in 2001 with purse seine accounting for 98% of the catch in that year.

Western Tuna and Billfish Fishery

The Western Tuna and Billfish Fishery (WTBF) extends westward from Cape York Peninsula (142°30’E) off Queensland around the west coast of Western Australia and from there extends eastward across the Great Australian Bight to 141°E at the South Australian/Victorian border. Broadbill swordfish (Xiphias gladius) yellow fin (Thunnus albacares) bigeye tuna (T. obesus) albacore tuna (T. alalunga) and longtail tuna (T. tonggol). Its value in 2005-06 was $3.2 million. Pelagic long-line, minor line (hand line, rod and reel, troll and poling) and purse seine.

4.9.3 Oil and Gas Exploration and Production

The nearest oil and gas facilities are all located well away from the Jansz-Io well area, mostly in the easterly direction. The drilling programme will not impinge on any restricted area associated with oil and gas production facilities.

Oil exploration activities in the Indian Ocean off Western Australia commenced in the late 1960s. Since this time many well drilling operations have been conducted throughout the region, and searches for new sources of hydrocarbons are actively being pursued in the area.

4.9.4 Shipping and Ports

There are no major ports in or near the Jansz-Io well area. The nearest ports are those of Dampier (LNG, bulk iron ore) and Port Hedland (bulk iron ore), which are located 240 km and 430 km east northeast of the drilling area respectively.

Minor ports are located at Onslow and Exmouth, approximately 210 km southeast and 235 km south from the Jansz-Io well area respectively. The main users of these minor ports are commercial fishing and charter vessels.

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

The centre of the north-south shipping lanes passes the Jansz-Io well location approximately 70 km to the west and southeast. Liaison with the Australian Maritime Safety Authority (AMSA) will advise shipping activity. This advice, coupled with standard shipping practices (that is, notice to mariners, lights etc), will operate to ensure that collision is avoided.

There will be three vessels supporting the rig with one vessel in close range of the 500m exclusion zone at all times. One of the duties of the supporting vessels is to keep a lookout for other ships and to ensure that collisions are avoided.

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

5 ENVIRONMENTAL IMPACTS, RISK ASSESSMENT AND MANAGMENT

An analysis of environmental hazard and risk has been conducted for the Jansz-Io drilling programme. Its purpose was to:

Identify and assess hazards to the public and the marine environment during the drilling programme.

Undertake a scenario-based risk assessment, using the risk management method based on the Australian Standards, Risk Assessment (AS4360:2004).

Identify and rank hazards and determine appropriate risk reduction measures.

The following definitions are critical in the understanding of hazard and risk assessment.

Incident: an event capable of causing critical, major, moderate or minor damage to the environment, or negligible damage with no significant environmental effect.

Hazard: a physical situation with the potential for damage to the environment, human injury, damage to property or a combination of these.

Risk: a combination of the likelihood of a specified undesired event occurring within a specified period or in specified circumstances and the severity (consequence) of the undesired event from occurring.

5.1 Hazard Identification

The process of hazard identification and risk management are divided in three main sections (reproduced from AS/NZS 4360:2004):

External and environmental hazards (global hazards):

- Project-specific hazards (project implementation issues).

- Personnel health hazards (a global hazard).

Individual and special operations hazards during operations that is exceptional because of size, complexity or timing.

General and routine work performed according to standard procedures.

5.2 Risk Scenario

A scenario for realisation of each environmental aspect causing the hazard was developed. Each scenario included:

A description of the scenario and root cause of the hazard.

Existing risk mitigation or prevention measures (that is, protection systems and management mechanisms) that are currently in place or are standard safety measures.

A description of the potential environmental consequence.

The risk calculated by the likelihood of that particular consequence of the noted severity actually occurring.

As per the AS/NZS 4360, ExxonMobil Environmental Management Manual, and OIMS Risk Management System (Table 5.1 and 5.2) the key stages of environmental risk management include:

risk identification

risk analysis

risk evaluation

risk treatment

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

Table 5-1 Environmental Impact Consequence Levels

Consequence Level Environmental Impact (Corporate Matrix terms)

Working Definitions for Considerations

I Potential Widespread

Long-Term

Significant Adverse Effects

Major multifunctional emergency

Significant, long-term cleanup

Potential widespread, long-term, significant adverse effects on the environment, including soil, air and groundwater, or on a large community

Protected species endangered or migratory path interrupted

II Potential Localised

Medium-Term

Significant Adverse Effects

Immediate-level emergency response

Cleanup extending over weeks or months

Potential localised, medium-term significant effects on the environment, including soil, air and groundwater, or on a small community

Sensitive species endangered or migratory path interrupted

III Potential Short-Term

Minor Adverse Effects

Local emergency response

Cleanup work for days or weeks

Potential short-term, minor adverse effects on the environment, including soil, air and groundwater or on a few members of the public

IV Minor or no cleanup required Confined to site or close proximity

Source: Esso Risk Assessment and Management Manual – RAMS 90-A

Table 5-2 Probability Ranges

Probability Range

Corporate Matrix Definition

Qualitative Interpretation Guidance Quantitative Interpretation

Guidance

A Possibility of Repeated Incidents

Very Likely

Has happened several times at the site or many times in the Company*

0.1 to 1 (midpoint to 0.3)

B Possibility of Isolated Incidents

Somewhat Likely

Has happened once before at the site or many times in the Company*

0.01 to 0.1 (midpoint to 0.03)

C Possibility of Occurring Sometime

Unlikely

Has not happened before at the site or has happened a few times in the Company*

0.001 to 0.01 (midpoint to 0.003)

D Not Likely to Occur Very Unlikely

Have been isolated occurrences in the Company or has happened several times in the industry*

0.0001 to 0.001 (midpoint 0.0003)

E Practically Impossible Practically Impossible

Has happened once or not at all in the Company*

Has happened a few times or note at all in the industry*

<0.0001

Source: Esso Risk Assessment and Management Manual – RAMS 90-A

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

The “Guidelines for the Preparation and Submission of an Environment Plan” [Ref 51] defines risk as “the chance of something happening that will have an impact on objectives. It is measured in terms of consequences, and their likelihood of occurrence.”

The Guidelines also state that consequence levels should be allocated based on the effects of a given impact on specific ecological values, physical or social parameters such as a loss, injury, an expressed concern, disadvantage or gain and should take into account the sensitivity of the area in which the activity is taking place.

5.3 Risk Matrix

Each scenario was then assessed using the risk matrix approach (Appendix 5). A risk estimate was made on the basis of the likelihood of the consequence occurring. The ExxonMobil Risk Assessment and Management Manual – RAMS 90-A Risk Matrix was used to assess each scenario. The risk matrix is appended for reference (Appendix 5).

5.4 Risk Reduction Measures

Risk reduction measures were applied to risks deemed to be too high, that is, ‘Extreme’ or ‘High’ on the risk matrix. The residual risk for the hazard scenario was then reassessed. The residual risk associated with all identified hazards was reduced to an acceptable level by this process.

5.4.1 Philosophy of Risk Reduction

AS/NZS 4360:2004 proposes a four-point scale of management action to be taken according to the risk classes of Table 5-3.

Table 5-3 Risk reduction philosophy

Level of Risk Philosophy

Extreme/ intolerable risk

Unacceptable risk that will not be tolerated by ExxonMobil under any conditions and must be engineered down to a lower risk level. The amount by which such risks can be reduced will depend on the control that the drilling has over the factors involved in the hazardous event. For example, where a major risk-producing factor is the project’s interface with the general public, fewer options are available to reduce that risk than in cases where the general public are not involved.

High/ undesirable risk

High/undesirable risks require that the engineering design or method should be altered to remove the hazardous event or to reduce the associated frequency or consequence severity so as to place the risk in a lower risk level.

Moderate/ undesirable risk

Moderate/undesirable risks require that a management plan be determined for the hazardous event to prevent its occurrence and to monitor changes that could place the risk in a higher level. The management responsibility must be specified.

Low/tolerable risk Low/tolerable risks require no further treatment other than monitoring as the project progresses to ensure that there is no potential for the risk level to increase with time. These risks can be managed by routine procedures.

5.5 Environmental Hazard and Risk Assessment

The risk assessment for Jansz-Io campaign was conducted in April 2011 to determine the environmental risks associated with Jansz-Io campaign, in order that controls could be identified, and the risk to the environment be minimised to As Low As Reasonably Practicable (ALARP). The workshop was attended by representatives from Transocean, ExxonMobil and third party contractors.

Appendix 1 presents the outcomes of the environmental hazard and risk assessment for the Jansz-Io drilling programme. The consequence and likelihood rankings are interpreted from Tables 5-1 and 5-2. The risk evaluation draws from the matrix in Appendix 5. For the purposes of the risk assessment workshop, the drilling campaign was split into the following key areas:

MODU movements including support vessels.

Support activities including helicopters, ROV, Field Vessels, personnel issues.

Reservoir related issues.

Drilling and completion of wells.

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

Temporary suspension of wells.

Flow-back and testing.

SIMOPS activities (including vessel interactions, particularly with Subsea tree installation vessel).

Jansz-4 re-entry and conversion.

Subsea trees Installation.

Shared services with Chevron Australia (including emergency response services, support vessels, aviation fuel and supply base).

Seasonal variations (e.g. cyclones).

Mitigation measures have been developed from experience developed during previous drilling operations (including from Jansz-1, 2, 3 & 4 and Io 1 & 2) and from the experience of ExxonMobil, Transocean and drilling contractors in other offshore drilling operations in Australia and around the world. Management measures are based on Australian petroleum industry best practice environmental management guidelines, as defined by the Australian Petroleum Production and Exploration Association (APPEA) Code of Environmental Practice (1996).

There were 28 environmental risks identified with no activities assessed as being of ‘high’ risk or greater for the drilling programme. This reflects the application of appropriate management and mitigation measures. Ten risks were assessed as medium and 18 as low. All risks were considered to be ALARP with the identified risk reduction measures implemented.

5.6 Environmental Risk Register

The risks identified in the Jansz-Io drilling campaign environment risk assessment are detailed in Appendix 1.

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


6 DESCRIPTION OF ENVIRONMENTAL EFFECTS AND RISKS

This section outlines potential environmental effects and the impacts on the environment that may occur from routine drilling operations in offshore areas.

The potential environmental effects included in the environmental risk assessment (Section 5) are related to:

Disturbance to marine fauna.

Disturbance to benthic habitat.

Drilling mud and cuttings discharge.

Deck drainage (overboard discharge due to rainfall and deck wash-down).

Sewage, greywater and putrescible wastes (discharge after treatment).

Solid and hazardous wastes (all wastes stored onboard for onshore disposal).

Translocation of unwanted species by ballast water discharge, hull fouling and imported materials.

Interference with commercial fisheries.

Interference with shipping.

Interference with recreational vessels.

Oil spill scenarios (including well testing, refuelling incidents, vessel collision and blow-outs).

Atmospheric emissions of exhaust gases and carbon dioxide.

Well testing emissions and discharges.

Each of the effects identified above is described below.

The following discharges are estimated according to the planning basis. Changes to the plan including, but not limited to, engineering optimisation, operational requirements and contingency (resulting from equipment or processing failures) may result in variations in the stated discharge volumes. Significant deviations will be internally reviewed and reported to the Authority if appropriate.

6.1 Disturbance to Marine and Benthic Communities

6.1.1 Vessels

Activity

Supply and support vessels will be transiting between the DWF and the onshore supply base. Vessels will be well lit at night and during times of poor visibility.

The DWF will use a dynamic positioning system utilising thrusters to position itself over the drill site. This negates the need for an anchor spread to hold the rig in position removing the risk of anchor damage to benthic habitats.

In order to accurately drill the Jansz-Io wells, a dual/ redundant positioning subsea array is required at location to provide positioning data to the DWF. The subsea array will be deployed and calibrated from a work boat over a period of 12 – 14 hours depending on weather and sea state conditions.

22 transponders (deployed in 2 x 11 arrays [each of 10 x LBL and 1 x USBL]) are to be located in a circle around the proposed drill site location at a stand-off distance of ~ 300m radius. All transponders will be inside the gazetted Petroleum Safety Zone at the drill location which extends to 500m from the drill centre.

The transponders are secured on location on the seabed by weighted array frames each weighing 1.2 tonnes. Each array frame has a 32mm steel base plate and a 2 x 2 metre footprint.

In additional a further five Sonardyne subsea transponders at each location will be deployed for surveying purposes in the Jansz-Io wellhead locations.

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Assessment

Given the speed and manoeuvrability of supply vessels, there is a remote risk of physical impact with marine mammals. Support vessel activities typically occur for approximately 2% of the total drilling duration (McCauley in APPEA, 2005).

Jansz-Io support vessel activity is not considered to be any different to other vessel activity and its potential to disturb marine species is considered to be low.

ExxonMobil considers the installation of the transponder array, the operation of the array and the recovery operation of the transponders and clump weights to pose a minor risk to the environment as noted below:

Negligible seabed disturbance or loss of species abundance for a period ~ 2 year due to the clump weights.

The items are to be located inside a Petroleum Safety Zone that will be gazetted.

Transponders operate (transmit) in the range of 13 – 15 kHz and receive in the range of 9-12 kHz. Sonardyne Wideband transponders operate in the medium frequency (MF) band between 18 - 36 kHz, with a power output range of 184 to 193dB. This is the same frequency as most vessels based echo sounders as well as the USBL system installed on the Deepwater Frontier. These systems are used world-wide and have no impact on marine life.

ExxonMobil’s sub-contractor has no records of interferences with marine life with respect to transponders and clump weights.

The array frames and transponders contain no sources of fluid discharge to the environment.

The array frames and transponders will be retrieved at the end of the activity.

Management

Environmental induction shall be provided to crew identifying environmental sensitivities and protection measures. All vessels will adopt the proximity distance requirements of the 2005 Australian National Guidelines for Whale & Dolphin Watching [Ref 2] to ensure impacts to cetaceans are minimised. On this basis, the environmental risk from the presence of the DWF and its associated support vessels on marine mammals is assessed as inconsequential.

At the end of the drilling activity the transponders, will be recovered by a work boat. The cement blocks will remain in-situ. A hazard assessment has indicated that after three years in-field the cement blocks are likely to be covered by sedimentation and potentially colonised by various benthic communities. The hazard assessment determined that there would be a greater impact from removing the cement blocks. On this basis the cement blocks will be left in situ but the transponders will be removed.

6.1.2 Lighting

Lighting can cause a change in the behaviour of fauna particularly to nesting turtles (hatchlings) and birds. However, given the distance from the nearest shoreline, and the fact that there are no nearby breeding or nesting islands in proximity to the planned drilling activities, the likelihood of impacts is considered to be highly unlikely.

6.2 Use of Chemicals and Radioactive Materials

Activity

Various chemicals will be transported, stored, handled and used in the drilling operations. The DWF and support vessels will have various chemicals on board including cleaning agents and detergents, maintenance products, radioactive materials and products required for drilling such as potassium chloride (KCl) and various polymers. Limited amounts of these chemicals will be stored onboard the DWF.

Spills of hazardous substances could result in localised contamination around the drilling MODU impacting upon water quality with potential impacts to plankton or benthic organisms.

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Assessment

Risks associated with radioactive substances and hazardous materials have been assessed in detail as part of the Structured Hazard Identification and the Transocean DWF Hazards, Risks and Controls Register. This register identifies typical risks and controls (preventative) associated with drilling campaign hazardous materials.

All cleaning agents and detergents will be low toxicity, readily biodegradable and free of biocides, except those essential for hygiene and medical use. Chemicals that may be discharged as part of the drilling campaign will be assessed against ExxonMobil project-specific performance standard for offshore chemical assessment prior to use.

Radioactive sources used during the Jansz-Io campaign are associated with logging activities.

Management

Chemical spills will be minimised through the following controls:

chemicals handled according to Hazardous Substances Procedures;

chemical storage and handling areas will be bunded and routinely inspected for leaks and spills;

training is provided for those personnel handling chemicals;

chemicals are selected considering environmental toxicities and impacts;

MSDSs are made available for all chemicals; and

spill kits provided in appropriate locations.

Chemical transfers between supply vessel and rig shall be in accordance with Transocean’s operational procedures and Australian Offshore Support Vessel Code of Safe Working Practice requirements [Ref 2].

Dangerous goods and hazardous substances transported to or from the MODU will be documented in accordance with the National Code of Practice (NCP) for the Control of Workplace Hazardous Substances and NCP for Storage and Handling of Dangerous Goods.

Standard controls include compliance with International Maritime Dangerous Goods (IMDG) Code and AMSA Marine Order #41, maintaining inventories of all chemicals and associated Material Safety Data Sheets (MSDS) on board, providing appropriate storage, bunding, tank protection and segregation as required, and regular inspections of storage facilities (Transocean HSE EMS 2.3.17).

Chemicals on the DWF are managed through “THINK Plan” (Transocean HSE EMS 2.3.17). All chemicals carried and used on the DWF will be listed on the Master List of MSDSs on board the DWF and will be available to all personnel. An inventory of all hazardous materials (including quantities and location) will be maintained on the DWF by the OIM, the EMDC Drilling Supervisor (offshore) and the ExxonMobil Materials and Logistics Coordinator (onshore). The DWF will carry appropriate spill clean up or decontamination material to handle any of the chemicals on board. Hazardous chemicals will be securely stored in appropriately bunded and enclosed or covered storage facilities.

Radioactive sources will be stored in an appropriate bunker and handled only by certified Schlumberger personnel (wireline) and Baker Hughes personnel (LWD).

The hazards associated with hazardous substances and dangerous goods on board the DWF will be communicated as described in the DWF Hazardous Materials Communications Programme.

Support vessels implement similar programmes to prevent uncontrolled releases of chemicals to the marine environment.

The drilling chemicals to be used during the Jansz-Io drilling campaign are listed in Appendix 2. The Appendix includes the expected quantity, type and class of hazardous substance (HS) or dangerous good (DG) in line with National Occupational Health and Safety Commission (NOHSC) or European Union (EU) criteria. EU Hazardous Chemical identification is in alignment with the NOHSC risk classification.

No banned substances will be used in the Jansz-Io campaign.

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Potential Residual Issues/Impacts

Although there is the potential for a small chemical releases during the storage and handling of drilling chemicals, given the adopted control measures and high dispersion and dilution within the North West Shelf environment, chemical spillage impacts to the marine environment is localised with minor pollution at the site. On this basis the environmental risk associated with such event is considered as inconsequential.

6.3 Discharges Associated with the MODU

6.3.1 Drilling Fluids and Cuttings

Activity

Biodegradable water based muds (WBM) will be used wherever practicable. Non aqueous drilling fluids (NADF) will be used when technically and geologically justified or where significant cost or schedule benefits exist.

Clear brines will be used in the completions and a brine-based gravel pack gel will be used as part of the NAFPac process.

Water Based Muds (WBM)

WBM will be used to drill top hole sections (914mm and 660mm), composed of a combination of seawater and hydrated bentonite sweeps. This system has been widely used in the North West Shelf (NWS). These sections drilled without a marine riser in place and the returns will be taken to seafloor.

The whole fluids and fluid components of the WBM have low toxicities, are readily miscible and dispersed in the marine environment and are routinely accepted for use by the regulatory authorities [Ref 37]. They are classified as “almost non-toxic” (96 hr Mysid LC50 between 10,000 and 100,000 ppm) or non-toxic (96 hr Mysid LC50 > 100,000 ppm; [Ref 52]. These fluids Barite and bentonite may contain some trace heavy metal concentrations (less than 3 ppm cadmium and 1 ppm mercury), but not in a readily bio-available form. Both substances have very low toxicities and are considered by OPSAR to pose little or no risk to the environment [Ref 47].

After completion of the upper hole sections remaining WBM contained on board the DWF will be discharged to the environment as part of tank cleaning and prior to the use of non-aqueous drilling fluids (NADF).

The effluents from tank cleaning will be discharged as well as any unused bulk materials in the tanks.

Non–Aqueous Drilling Fluids (NADF)

NADF will be used to drill the 17-1/2” (445mm) and 12-1/4” (311mm) intermediate hole sections, and the 8-1/2” x 9-7/8” (216mm x 251mm) production hole. The NADF is comprised of an iso-paraffin (Saraline 185V) base fluid, brine and solids that allow the drilling fluid to have the desired density to maintain wellbore integrity. The NADF proposed is classified as a ‘slightly toxic’ to ‘non-toxic’ [Ref 52] drilling fluid that does not contain any aromatic hydrocarbons (known to contribute to biological toxicity) and has low water solubility.

The discharge of NADF to the environment will be minimised by recycling the drilling fluid during operations through solids control equipment installed on-board the Transocean Deepwater Frontier specifically for the Jansz-Io work program. This new equipment consists of six (6) new shale shakers, two (2) cuttings dryers, and three (3) decanting centrifuges.

The planned NADF ROC discharges to the environment meet the following characteristics:

1. NADF ROC will be less than 10% for each of the 17-1/2”, 12-1/4”, and 8-1/2” x 9-7/8” hole sections, based on cuttings generated in each section.

2. NADF ROC (including residual NADF from conditioning) will be less than 10% for the combined 17-1/2”, 12-1/4”, and 8-1/2” x 9-7/8” hole sections for each well.

The NADF will be conditioned to remove fine particles generated in previous hole sections in preparation for completion operations. Solids and the residual NADF discharged during this activity will be allocated back to the 17-1/2”, 12-1/4”, and 8-1/2” x 9-7/8” sections based on the relative volume of cuttings generated in each section (for each well).

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


The approximate distribution of cuttings volume by hole section for the Jansz wells is shown below (percentages vary depending on measured depth of well):

1. 17-1/2” hole: 65-80%

2. 12-1/4” hole: 15-25%

3. 8-1/2” x 9-7/8” hole: 5%-10%

Interface Fluids

During the displacement from WBM to NADF to brine and vice versa, blending the two fluids occurs generating volumes that are unsuitable for recycling directly into circulating active fluid system. These interface fluids will be managed during displacements by containing NADF interfaces on surface, testing oil content before discharge overboard. In addition high viscosity pills will be discharged.

All primary components of the mud system have been ranked under the CHARM system (refer Section 3.7.3) and provided with either a D or E ranking. The Saraline 185V (base fluid) is CHARM rated (D). It is currently approved by DMP and is being used by other petroleum companies conducting drilling in the offshore waters of Australia. Saraline 185V will be mixed with various additives until the mud reaches the specification required. Generally a mix consists of approximately 60% base fluid and 40% additives. Approximately 3.6% (volume by volume) of this whole NADF is made up of the chemicals which do not have an OCNS/CHARM rating. The remaining components, making up approximately 96% of the whole NADF, all have a low toxicity OCNS/CHARM rating. Table 6.1 shows the constituents of the mud fluid system.

Several chemicals used within the mud system are not CHARM/ OCNS rated. Table 6.2 shows the non-CHARM/OCNS rated chemicals. Chemical’s which do not have the desired rating, do not have an equivalent which is rated and also has the same functionality is shown in Table 6.2. Table 6.2 shows the complete list of non- rated chemicals which may be used in the Campaign. The table provides a justification for the usage and also how each chemical may be used. Ten of the twelve listed chemicals are contingency chemicals used for troubleshooting (e.g. loss of circulation, unexpected H2S).

Note that this same process for interface fluids will apply to riser displacement activities (cyclone preparedness/ SIMOPS/ BOP repairs/ HXT installation).

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

Table 6-1 Constituents of Drilling Fluid

Non Charm/ OCNS Rated

MUD WEIGHT: 1.26 g/ml NAF : WATER RATIO MUD SYSTEM: Novatec

PRODUCT COMPANY BRAND NAME PRODUCT CONCENTRATION FOR 1

LAB BBL (350mls)

Grams Millilitres % v/v

BASE FLUID (NAF) Saraline 185V 155.140 200.699 57.339

WATER 87.740 88.033 25.151

BARITE 137.000 32.619 9.319

CaCl2 (97% PURITY) (added as brine) 39.500 11.273 3.221

SECONDARY EMULSIFIER * Novatec-S 10.000 10.000 2.857

VISCOSIFIER Bentone 38 4.500 2.647 0.756

FLUID LOSS AGENT (LIQUID) * Novatec-F 2.500 2.475 0.707

LIME 5.000 2.273 0.649

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

Table 6-2 List of Non-rated Chemicals (Jansz-Io drill campaign)

Chemical Purpose Concentration% vol/vol

Justification Rating or equivalent Used in WA

NOVATEC S The purpose of the product is as secondary emulsifier in the Novatec system. Alternatives to this product are available but are also not OCNS/CHARM registered. This product has been and is still being used offshore WA as an additive to the M-I Novatec synthetic based mud system.

2.857% v/v Will only be discharged as a proportion of whole mud retained on cuttings (in the concentrations shown in column 3 adjacent)

OCNS/CHARM rated alternative unavailable

Yes

NOVATEC F Has been and is still being used offshore WA as a core additive to the M-I Novatec synthetic based mud system the purpose of the product is to reduce fluid loss in the novatec system

0.707% v/v Will only be discharged as a proportion of whole mud retained on cuttings (in the concentrations shown in column 3 adjacent)


Yes

CIRCAL 1000 This product is Calcium Carbonate (Limestone).This product is used as

a contingency lost circulation material.

Contingency Only

This product is identical (i.e. CaCO3) to other forms of Calcium Carbonate which are rated in the North Sea. ChemAlert rating is GREEN

Same as Safecarb OCNS Rating E registration # 2451

Yes

CIRCAL 60/16 This product is Calcium Carbonate (Limestone).This product is used as


Contingency Only



Yes

CIRCAL Y This product is Calcium Carbonate (Limestone).This product is used as


Contingency Only



Yes

Form A Set Acc The purpose of the product is to act as an accelerate to the bonding process to the Form-A-Set AK and Form-A-Set XL products.

Contingency Only

It is therefore only a contingency material for the Jansz-Io program and will only be used if severe (>50bbl/hr) down-hole losses are encountered and potential for discharge is extremely low.

NA Yes

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development



Form A Set AK This product is used as a contingency lost circulation material. It is cross linked natural semi synthetic polymer which is inert and stable

Contingency Only

It is a required contingency material for the Jansz-Io program in the unlikely event of severe down-hole losses. If used, it is typically used in relatively low quantities (< 1 mt per application). Potential for discharge is extremely low as this material will only be pumped into the well if down-hole losses are severe (> 50 bbl/hr) and therefore returns are not likely

NA Yes

Form A Set Ret The purpose of the product is to act as an decelerate to the bonding process to the Form-a-set AK and Form-a-set XL products.

Contingency Only


NA Yes

Form A Set XL The purpose of the product is to act as a chemical cross linking to the Form-A-Set AK product.

Contingency Only


NA Yes

NOVATEC P The purpose of the product is to as primary emulsifier in the Novatec system alternatives to this product are available but are not OCNS/CHARM registered. At present this product is not intended to be added to the mix due to technical requirements, however it may need to be added if technical assessments require.

Contingency Only

Will only be discharged as a proportion of whole mud retained on cuttings (in the concentrations shown in column 3 adjacent)


Yes

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development



Thermoset F/M This product is used as a contingency lost circulation material. It is vulcanised rubber which is inert and stable.

Contingency Only

It has been assessed by ChemAlert as an Amber rated product. This Amber rating has been applied due to the product being described as a skin irritant. It is classified as hazardous according to safe work Australia criteria based on the risk that it can irritate skin, eyes and respiratory system. This type of product is not discharged in the north sea due to the zero discharge regulations in force there and therefore does not have a rating or a product that is comparable. It is a required contingency material for the Jansz-Io program in the unlikely event of severe down-hole losses and if used is typically used in relatively low quantities (< 1 Mt per application). Potential for discharge is extremely low as this material will only be pumped into the well if down-hole losses are severe (> 50 bbl/hr) and therefore returns are not likely.

NA

ZINC OXIDE On the Jansz wells it will only be used as a contingency in the extremely unlikely event that H2S gas is encountered.

Contingency Only

None of the offset well to date have indicated this is likely to occur, however it is desirable to have contingent Zinc Oxide available on health and safety grounds. This product is not intended planned for use during the Jansz campaign. Possible alternatives considered are iron based products; however these too can be toxic when in soluble form. Use of the product is requested primarily based on its superior performance as a scavenger of H2S and therefore will minimise likelihood of a safety incident if H2S is encountered during the campaign.

NA Yes

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

Drill Cuttings

Drill cuttings are inert pieces of rock, gravel and sand removed from the well during the drilling process. The characteristics of the cuttings to be discharged can be predicted from the lithology of offset wells drilled in the permit. The cuttings are expected to comprise calcarenite, shale and sandstone. The cuttings retrieved are expected to range in size from very fine to very coarse particles, with a mean size no larger than one centimetre.

ExxonMobil’s Offshore Drill Cuttings Discharge Standard (DCDS) has been used in selecting and implementing cuttings waste treatment and disposal requirements for these wells.

For Jansz-Io drilling operations marine discharge has been selected to dispose of drill cuttings at site, where an evaluation of the risks and benefits of the full range of disposal options indicates that discharge is an environmentally acceptable practice.

ExxonMobil conducts environmental assessments for its drilling operations prior to undertaking drilling activity. Drill cuttings management depends upon the local conditions and sensitivities of the region, the risks presented by the drilling operations (fluids, geological structures, and other environmental conditions), and available disposal options.

ExxonMobil implements a global practice for use of cuttings dryers on offshore drilling rigs where NADF cuttings are discharged. This secondary processing of drill cuttings reduces the amount of NADF adhered to the cuttings being discharged, which generally results in reduced impact to the environment.

Drill cuttings with residual adhered NADF will be discharged via the overboard discharge line after treatment through the secondary processing equipment; Cutting dryer(s) and centrifuge(s). Samples will be taken at both overboard discharge points to monitor residual NADF and comply with the < 10% by dry weight limit (averaged over the NADF interval). If the cuttings dryers are non-operational then the cuttings will continue to be discharged after processing through the shakers provided the limit is achieved.

Table 3-5 and Table 3.6 in Section 3 provide the volume of cuttings discharged and volume of anticipated mud losses (ROC) per hole section for each well for drill centre 1 and drill centre 2 respectively.

The environmental impacts of drill cuttings discharges are both physical and biochemical. Physical impacts include:

Creation of sediment plume, which decreases light penetration.

Smothering of benthic organisms.

Changing of seabed habitat characteristics such as sediment size.

Biochemical impacts may be due to the mineral composition of the cuttings and the discharge of drilling muds. These impacts include:

Acute or chronic toxicity (e.g. mutagenicity, reduced health, mortality).

Potential for bioaccumulation.

The level of environmental impact will be determined by a combination of factors such as:

Sensitivity and distribution of organisms and habitat in the surrounding area.

Composition of cuttings particles and drilling mud.

Characteristics of cuttings (e.g. size and abrasiveness of particles).

Breakdown rate of chemicals within the drilling muds.

Volume of discharge.

Depth of discharge.

Timing of discharge.

Local metocean conditions (which will determine rate and area of dispersion).

Cuttings discharged in deepwater results in thinner and more readily dispersed cuttings accumulations than cuttings piles associated with conventional platform drilling.

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

Given the low sensitivity of the receiving environment, the species of organisms likely to be within proximity of the well and the use of NADF, it is highly unlikely that significant environmental (physical and/or biochemical) impacts will occur.

Assessment

WBM to be used for the Jansz Development drilling programme are classed as almost non-toxic (96 hr Mysid LC50 between 10,000 and 100,000 ppm) or non-toxic (96 hr Mysid LC50 > 100,000 ppm [Ref 52]. The WBM will be circulated to the seafloor during riser-less drilling.

ExxonMobil’s process is to use OCNS/CHARM rated (Gold, Silver E or D rated) chemicals for planned discharges. Where these chemicals (or an equivalent which is rated) do not exist, then an assessment is made for use by exception. The chemicals which have been listed which do not have the desired rating do not have an equivalent which is rated and also has the same functionality.

All primary components of the NADF mud system have been ranked under the CHARM system and provided with either a D or E ranking. The Saraline 185V (base fluid) is CHARM rated (D). It is currently approved by DMP and is being used by Chevron Australia, Shell and Hess. The Saraline 185V is synthetic oil (defined by EPA) as it is derived from gas to liquid process (as opposed to being distilled directly from crude oil).

Approximately 3.6% (volume by volume) of this whole mud system is made up of the chemicals which do not have an OCNS/CHARM rating. The remaining components, making up approximately 96% of the whole mud, are all rated. ExxonMobil’s assessment is that in these minor quantities, and given the receiving deep-water, high current environment, the incremental effect of these additives on the remaining components of the mud system is negligible.

ExxonMobil assesses that the discharged chemicals are rated such that they have minimal impact on the environment. The discharge target level of NADF is ≤10% by volume in all interface fluids.

The return flow of NADF from down hole is via the mud return line to the shale shakers. Drilling fluids exiting the shale shaker underflow is then returned to the mud tanks to be pumped down hole as re-circulating fluid system.

The bulk of the NADF will be separated from the cuttings using the drill rig's shale shakers and cuttings dryers and re-circulated to the drilling mud system for re-use. The bulk of the NADF will be recovered and recycled further for reuse. The quantities of NADF ROC are low and coupled with the low toxicity CHARM rating are assessed to have a negligible impact to the environment.

The process described is illustrated in the simplified diagram below – Representative Mud Circulation System. In regard to the diagram it should be noted that there are in fact two discharge points, both discharge points being sampled to ensure the correct weighted average is used for the ROC calculation. One discharge point is off the cuttings dryer from where the bulk of the cuttings will be discharged. The non-aqueous drilling fluid (NADF) recovered from the cuttings processed by the cuttings dryer is further processed through a high speed centrifuge to separate any remaining fine solids from the NADF. The discharge point from this secondary centrifuge dryer also has a sample point at the point of discharge.

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

Figure 6-1 Representative Cuttings Processing System and NADF Recovery System

Management

The planned wells have been designed to minimise the generation of cuttings within the technical constraints of drilling the wells.

The discharge of NADF to the environment will be managed by re-circulating the NADF to the rig to where it is processed by solids control equipment, including shale-shakers, cuttings dryers and centrifuges to recover as much NADF from the cuttings as possible and ensure NADF retention on cuttings discharged is as low as reasonably practical (ALARP). Six new shale shakers and two cuttings dryers have been installed to reduce the volume of NADF retained on cuttings to a target level of less than 10% by dry weight for each hole section drilled prior to discharge to the ocean (See section 6.3.1 for details). Whole NADF will not be discharged to the marine environment during drilling.

At the end of the well any unused NADF will be returned to shore for re-use, recycling or disposal.

Where possible, WBM will be recovered and re-circulated, or contained for future use for the next hole section on the drill centre and will not be directly discharged to the environment. After completion of all wells, to be batched drilled at a drill centre, the WBM will be discharged to the marine environment at surface to aid dispersion. Before excess WBM is discharged, a check will be undertaken for marine mammals in the vicinity of the rig. If marine mammals are sighted the discharge will be delayed until they have passed.

Various strategies have been developed and will be adopted to ensure the release of NADF to the marine environment is kept to a minimum. ExxonMobil believes that these strategies provide best environmental practice for the use of NADF. These strategies are summarised below.

Approved contractors will control the storage and handling of the drilling fluid chemicals in conjunction with the National Code of Practice for the Control of Workplace Hazardous Substances and the National Code of Practice for Storage and Handling of Workplace Dangerous Goods.

Regular inspections of storage and handling facilities (Transocean HSE EMS), vessel procedures (Transocean HSE EMS Operations Policies and Procedures Oil Base Mud’s), environmental management and protection and Training (Transocean Competency Training and project and vessel inductions) and spill response capabilities will specifically address the management of NADF on board.

Polished NADF returns to active pit

NADF recovered from drill cuttings

Secondary processed drill cuttings flushed overboard

Drill cuttings from shale shakers transported to cutting dryer(s)

Cutting Dryer(s)

NADF shaker underflow returns to active pit

Active pit

Polished NADF returns to active pit

NADF recovered from drill cuttings

Secondary processed drill cuttings flushed overboard

Drill cuttings from shale shakers transported to cutting dryer(s)

Cutting Dryer(s)

NADF shaker underflow returns to active pit

Active pit

Sample Point

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

Written and approved procedures including a work permit will be adopted for all operations of the mud tank discharge manifold.

NADF will be stored in bunded areas where collected liquids will be vacuumed and primarily re-used within the mud system, or directed to containment tanks for treatment and possible offshore disposal.

If offshore disposal is conducted it will be as a result of establishing an approved offshore process for the treatment and phase separation of these fluids. At this stage the treatment will consist of de-mulsification and physical separation of the NADF from the aqueous phase. Recovered NADF from this process would be either recycled into the mud system or disposed to an onshore location.

In the absence of establishing the process described above the discharge target level of all oil/ NADF is ≤10% by volume.

All drains and sumps on the DWF that have any NADF potential for overboard discharge will be blocked, plugged or plated over to provide a physical barrier that will prevent discharging of mud.

A valve lockout/ tag-out system will be implemented to ensure containment of NADF.

NADF will be recovered and recycled by using shale shakers and cuttings dryer system so that any discharge to the ocean is minimised to that which is retained on cuttings.

ROV seabed surveys will be conducted pre and post drilling activities to assess the status of any residual cuttings piles. The ROV survey data will determine the need for any further action regarding the distribution of cuttings.

ExxonMobil have assessed this risk of slip joint packer failure for the campaign and incorporated learnings from previous incidents which have resulted in failures and spills to the sea. The controls and procedures in place have been implemented to mitigate the risk of spills to sea due to slip joint packer failure.

Slip joint packer failure has also been addressed as part of the ExxonMobil programmed risk assessment (accidental release of well fluids (mud/brine and/or cuttings). The programme risk assessment specifically identified the following risk controls:

Inspection of slip joints and secondary packer

Slip joint backup packer energization and alarm system

Further, ExxonMobil have issued a Drilling Alert Number 2008-0001-O (dated 1st July 2008) – Slip Joint Packer Requirements. The alert was issued as a direct result of ExxonMobil being aware of environmental incidents resulting from Slip Joint Packer Failure. The Alert was generated from the results of work performed by the ExxonMobil drilling Slip Joint Reliability Task Force.

The slip joint packer control system that will be used on the Deepwater Frontier is based on the outcome of this work and has undergone a shipyard upgrade. In addition the system will be tested with seawater after every BOP/ riser run.

There must be controls for dual packers in the riser telescopic joint (slip joint) that provide the following functionality:

i. An automatic and independent power supply system for energizing the secondary (lower) packer if the primary (upper) packer loses air/fluid supply pressure.

ii. A check valve arrangement (i.e. pilot-operated check valve, shuttle valve, etc.) to maintain closing pressure on the primary and secondary packer elements in the event control line closing pressure is lost.

iii. An audible and/or visual alarm indicating primary system pressure loss, located and monitored in a continuously manned space (e.g. Driller’s cabin, control room, etc.).

iv. A sufficiently sensitive pressure transducer in the closing circuit that engages the back up pressure supply system with no more than a twenty percent (20%) loss of the required closing pressure of the primary system.

v. Pressure gauges shall be installed on the closing lines of both the primary and secondary slip joint packers

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

6.3.2 Cementing

Activity

Following completion of drilling the upper hole sections, casing will be inserted and the annulus between the casing and the hole will be cemented. Cement fluids will be discharged (cement slurries, additives including surfactants, defoamers, lignins, inorganic salts and bentonite) at the seafloor or directly overboard while cleaning/ emptying tanks.

Spacers and interfaces will be discharged as required during the cementing pumping operations.

Assessment

The discharge of cement fluids will consist of cement and additives including surfactants, defoamers, lignins, inorganic salts and bentonite. Approximately 160bbls (25m3) of cement slurry will be discharged to seabed associated with the 20” (508mm) cementing activity.

The cement pump and rig piping used during cement operations will be flushed with water following cement operations, washings will be discharged overboard. In addition on completion of cementing operations remaining cement contained within the batch mixer, tanks, spacers etc., will be discharged overboard. This amount could be as much as 50bbls (8 m3).

In addition is estimated that approximately 250bbl of cement mix and additives will be discharged at surface as part of commissioning of the cementing unit.

Given the low sensitivity of the environment at the Jansz-Io location and the relatively low quantities of cement to be discharged, the cement is unlikely to have a significant effect on the environment.

Management

As per ExxonMobil project-specific environment performance standard for offshore chemical assessment, the Offshore Chemical Notification Scheme (OCNS) Chemical Hazard and Risk Management (CHARM) Model "hazard assessment" will be used for all chemicals discharged where possible or as otherwise stated.

OCNS rated cements will be used in cementing operations.

6.3.3 Gravel Pack Operations

Activity

Following TD of the well, an open hole gravel pack operation will be conducted. This will utilise the Exxon Mobil proprietary NAFPac technique, where a viscosified gel carrier fluid is used to displace NADF from the open hole/screen section, and transport the gravel pack proppant down-hole. During the process, recovered open hole sweep gel will be discharged overboard. The final step of the NAFPac process is reversing out excess gravel pack slurry/proppant with clear brine preceded by a wellbore clean-up pill train (surfactant/solvent spacers).

Prior to operations commencing, an acid pickle (dilute HCl) will be used to treat the surface piping and hoses. The spent acid will be discharged overboard.

All fluid interfaces will be monitored and discharged. Clean NADF recovered will be returned to the rig pit system for subsequent drilling activities. Following operations, any remaining pre-mixed gel and proppant will also be discharged overboard. Gel tanks and rig pits may also require cleaning, with any effluent discharged overboard.

Assessment

The discharge of gravel packing fluids will consist of KCl/NaCl/NaBr brine (or similar) and additives including gelling agent, gel breaker, iron chelating agent, biocide and surfactant. All components of the gel system are CHARM Gold rated or OCNS Rating E, with the exception of biocide which is CHARM Silver. Approximately 1900bbls (302m3) of gel could be discharged per well. In addition to this, approximately 100-bbls (16m3) of ceramic proppant could also be discharged per well. This also includes tank bottoms and silo remaining proppant.

The gravel pack pumps and piping/hoses used during gravel pack operations require a dilute acid pickle prior to operations commencing. This spent acid will amount approximately 10bbls (2m3) of 5% v/v HCl, mixed with water and corrosion inhibitor and will be flushed with sea water and discharged overboard.

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

During the gravel packing operation, displaced gel and NADF are returned to surface as part of the operational process. Clean gel will be diverted overboard in volumes up to 1200bbls (191m3). All interfaces monitored and discharged, and clean NADF diverted to back to the rig pits.

The wellbore clean-up pill used to displace the gel will consist of KCl/NaCl/NaBr brine (or similar) and additives including surfactants, viscosifiers. All components of the pills gel system are CHARM Gold rated or OCNS Rating E, with the exception of biocide which is CHARM rated Silver. The proppant is an inert ceramic. Discharged chemicals are rated such that they have minimal impact on the environment. The discharge target level of NADF is ≤10% by volume in all interface fluids. The volume of pills required to clean the casing between the gravel pack packer and the BOPs is estimated to 300-bbls (48-m3) and the required volume of brine is estimated to 1000-bbls (189-m3).

Fluids not suitable for overboard discharge will be contained for appropriate onshore disposal.

Riser displacement from NAF to KCl/NaCl/NaBr brine (or similar) will be done with an estimated 300-bbls (48-m3) of pills (brine with surfactants and viscosifiers) and approximately 2000-bbls (318-m3) of brine.

Contingency

If the gel QA/QC tests fail (for example gel souring, density problems, issues with rheology and sand settling properties), up to 2000-bbls (318-m3) of gel could be discharged per well.

In the event of a tool failure (downhole cross over tool) or a surface equipment failure (blender), up to 185-bbls (29-m3) of ceramic proppant could be discharged per well.

Management


OCNS rated chemicals will be used in all gravel packing operations.

6.3.4 Wellbore Clean Up Operations

Activity

Following gravel packing operations and prior to running the upper completion, wellbore clean-up activities will take place. This will involve running a variety of tools, such as casing scrapers, magnets and down-hole filters to provide mechanical cleaning of the casing and down-hole removal of solids from the brine fluid.

A variety of cleaning chemicals will also be utilised in this process. These will include KCl/NaCl/NaBr brine (or similar) viscosified brine spacers, surfactants and solvents to remove any NADF residue from the casing and drill pipe, as well as assist with solids removal.

The wellbore clean-up operations will be conducted in an all-brine environment, the well previously having been displaced to KCl/NaCl/NaBr completion brine (or similar) during gravel packing operations. Recovered spacers and chemical pills will be discharged, along with some volume of completion brine.

In addition to down-hole fluid clean-up, a surface filtration package will be utilised. This will consist of one or two diatomaceous earth (DE) filter presses, plus cartridge-type filtration pods. The completion brine will initially be filtered offline, with subsequent fluid returns to be passed through the surface filtration equipment. DE is loaded into the filter presses as a dry powder - used DE will be flushed from the presses with water and discharged.

It should be noted that after the initial displacement of brine to NADF and pit cleaning there is no NADF in the brine during filtration operations. Any NADF/ oil would effectively block the filtration process. In this instance the brine would be directed to pits. Any discharge from the pits would achieve the discharge target level of oil/ NADF of<=10% by volume.

ExxonMobil do not intend to conduct testing as any solutions passing through the filtration process will be free of NADF and oil.

Assessment

The discharge of wellbore clean up fluids will consist primarily of KCl/NaCl/NaBr brine (or similar), as well as surfactant & solvent spacers and viscosified brine pills. Brine volume to be discharged is

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

estimated at 3000-bbls (477 m3) per well. Chemical spacer volume to be discharged totals approximately 560bbls (89 m3).

All interfaces will be monitored and discharged, with clean fluids returned to the active pit system for future use or discharged.

Upon completion of wellbore clean-up activities, rig pits previously having contained NADF may be required to be cleaned in order to contain brine for future operations. This cleaning process will be conducted with surfactants/solvents to remove NADF residue and the pits finally flushed with seawater. All pit clean-up effluents will be discharged. Clean brine-based fluids or seawater will be discharged.

Periodic cleaning of the DE filter presses, as well as at the end of the filtration process, will result in approximately 10000kg of used DE being discharged with water. The DE itself is a naturally occurring, soft, siliceous sedimentary rock that is crushed for use as a filtration medium.

Management


OCNS rated chemicals will be used in all wellbore clean-up operations.

6.3.5 Upper Completion Installation and Wellbore Suspension

Activity

Following gravel pack and subsequent temporary isolation and abandonment of the well, the well will be re-entered, the wellbore cleaned up (as above), the brine will be filtered by the DE filter press, and the upper completion installed. These activities will be conducted with all brine fluids, including viscosified sweeps, surfactant and/ or solvent spacers pumped through the cased hole. During the process, all recovered spacers, interfaces, and brine will be monitored and discharged overboard.

Periodic cleaning of the DE filter presses, as well as at the end of the filtration process, will result in approximately 10000kg of spent DE being discharged with water. The DE itself is a naturally occurring, soft, siliceous sedimentary rock that is crushed for use as a filtration medium.

Following Upper Completions operations, any remaining pre-mixed spacers or inhibited packer fluid (O2 scavenger and biocide added to base brine) will also be discharged overboard.

Dependant on operations to follow, any brine remaining in tanks and rig pits could be discharged and the pits/tanks will be cleaned, with any effluent discharged overboard.

As part of wellbore suspension, Mono-Ethylene Glycol (MEG), and Methanol (MEOH) will be discharged during circulation/displacement operations.

Assessment

The discharge of well bore clean up fluids and inhibited packer fluids will consist of KCl/NaCl/NaBr brine (or similar) and additives including viscosifying agents, solvent and/or surfactant spacers, biocide and oxygen scavengers. Up to 2000bbls (636m3) of brine could be discharged per well. Up to 1000kg of DE powder may be discharged per well.

As part of wellbore suspension, Mono-Ethylene Glycol (MEG) will be discharged during circulation/ displacement operations. In addition it is possible that a glycol/water mixture may also be discharged from well test operations (recovered to the well test package during well clean-up and intervention operations).

It is estimated that a maximum of 50m3 of glycol/ water mix may be discharged per well.

The glycol that will be used will be CHARM D or E rated or an equivalent which is rated and which has the same functionality. ExxonMobil consider that the management criteria used (e.g. use of CHARM rated chemicals and minimise any discharge) to be ALARP.

Management

As per ExxonMobil project-specific environment performance standard for offshore chemical assessment, the Offshore Chemical Notification Scheme (OCNS) Chemical Hazard and Risk

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

Management (CHARM) Model "hazard assessment" will be used for all chemicals discharged where possible or as otherwise stated.

OCNS rated chemicals will be used in all completion operations.

6.4 Well Test Emissions and Discharges

Activity

The operation of the well clean-ups at the Jansz-Io wells will generate discharges to marine waters. The discharges will be:

Completion brine separated from the well stream and treated via oil-in-water filtering plant prior to discharge overboard.

Methanol, injected subsea and at surface to prevent hydrates. A fraction of this will be dissolved in completion brine and discharged overboard via oil-in-water filtering equipment.

Mono Ethylene Glycol (possible), mixed with water in pressure testing slick-line PCE or flushing surface filtering equipment. Discharged overboard via oil-in-water filtering equipment.

Condensate from steam heat exchangers.

MEG suspension fluid (50/50 volume of MEG/Brine) discharged at the end of the well test.

Assessment

The Jansz-Io wells will be flowed until the specified well clean up criteria have been met. Modeling indicates that each well will be cleaned up to the specified limits after approximately 24hrs of flow-back, although this flowing duration will be extended if the wells do not clean up as quickly as modeled.

The well test package has been designed to accommodate a maximum gas flow rate of 2.83MMm3/d (100MMscf/d), along with associated liquid production.

Assuming 24hrs of flow-back with a 2.83MMm3/d (100MMscf/d) maximum flow rate roughly equates to the volumes listed below, all flammable liquids and gas to be flared:

Base oil recovery (4hrs) - 48m3 (300bbl).

Ramping up to maximum gas rate (10hrs) - average gas rate of 1.42MMm3 (50MMscf/d) over 10hrs equates to 0.59MMm3 (21MMscf) gas. Associated condensate of 17m3 (105bbl).

Flow at maximum rate (10hrs) at 2.83MMm3/d (100MMsf/d) equates to 1.19MMm3 gas at standard conditions (42MMscf). Associated condensate of 33m3 (210bbl).

In summary and assuming a 24hr flow period with a maximum 2.83MMm3/d (100MMscf/d) flow rate creates flare emissions per well of approximately:

48m3 (300bbl) base oil

50m3 (315bbl) condensate

1.78MMm3 gas at standard conditions (63MMscf gas)

For each well clean-up operation, approximately1000 bbl (159m3) of 1.2SG (10ppg) mixed KCl /NaBr/NaCl (or similar) completion brine will be recovered to surface. This brine will also contain various compounds such as corrosion inhibitors, oxygen scavengers, etc in small amounts. The discharge of this solution is not anticipated to have any material environmental effect, and all chemicals discharged will be CHARM/OCNS rated where available. The recovered brine will be filtered to remove entrained oil to within acceptable limits prior to discharge overboard. Dependent on operations, there may be a requirement to discharge all the stored brine (e.g. in the event of contamination), resulting in a discharge of approximately 3000 bbl (477m3) of brine.

During the well clean-up, methanol will be injected both subsea and at surface for hydrate inhibition. This methanol will distribute in the oil / gas and water phases. The methanol in the oil and gas phases will be flared, whereas the methanol dissolved in the water phase will be discharged overboard via the oil-in-water filtering system. It is estimated that 100bbls (16 m3) of methanol in total will be injected per well clean-up for hydrate prevention.

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

There is a possibility that monoethylene–glycol / fresh water mixture will be recovered to the well test package during well clean-up and intervention operations. A glycol water mixture may be injected into the well for hydrate prevention if contingency operations require pressure testing of pressure control equipment or subsea valves. Glycol water mixture may also be used to flush surface sand filtering equipment in the low likelihood that solids are recovered to surface during the clean-up operation. Any glycol water mixture recovered would be separated and passed through the oil-in-water filtering system prior to disposal overboard. This volume is expected to be less than 25m3 (150bbl). While there is the potential for acute eco-toxicological impacts at the point of discharge, the volume discharged is considered low and is likely to be dispersed below levels causing acute toxicity quickly in the open ocean environment.

Produced formation water has not been observed during previous exploration well tests in the Jansz-Io field, and is not expected to be produced during the Jansz-Io completion campaign. Condensed water production is expected with the gas phase in the ratio of 0.4bbl fresh water per million standard cubic feet of gas produced. The condensed water produced will be gravity separated from the condensate in the test separator and passed through the oil-in-water treatment plant and tested for cleanliness prior to discharge overboard.

Based on the assumed flow duration and rates listed below, this equates to 4m3 (25bbl) of fresh water to be separated per well clean-up, checked for cleanliness and discharged overboard.

At the end of the well test the landing string will be filled with 50/50 MEG/Brine solution for hydrate prevention. This fluid will be discharged at the end of well suspension operations. Approximately 250bbl (50m3) would be discharged per well.

Management

All chemicals will be assessed for environmental impact prior to use (Environmental Performance Standard for Chemicals). No banned substances will be used in the Jansz-Io campaign.

Emissions from well testing activities will be reported under the National Greenhouse Emission Reporting Scheme (NGER). As the “controlling entity” (as defined under the NGER scheme) of the Deepwater Frontier, Transocean is responsible for reporting of greenhouse emissions associated with operation of the drill vessel.

Transocean are registered under the NGER scheme.

6.5 Deck Drainage

Activity

Deck drainage consists mainly of wash-down water and occasional rain water which may contain small amount of oil, grease, chemicals or detergent. Deck drains which contain rainwater only are directly overboard. Spills within designated deck containment areas where chemicals, oils and wastes are stored are either pumped out to the waste oil settling tank or mopped up utilising spill clean up materials.

Assessment

The current protocols for the collection and treatment of deck drainage ensure that no contaminated waste streams are routinely discharged from the deck drainage system to the marine environment. However, on wash-down events it is possible that minor quantities of oil and grease, mud and chemicals may enter the deck drainage system and be discharged overboard.

Drain and effluent systems on the facility are installed, operated and maintained as per Class requirements and the IMO MODU Code 1989. This arrangement includes:

Sewage system

Cuttings disposal system

Waste oil incinerator

Garbage and waste management system.

All drains and drain material are collected in various holding tanks located in the facility and are then processed by oily water separator systems.

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

During the use of NADF drains will be plugged so that any spill on board can be contained. All drains and sumps on the DWF that have any NADF potential for overboard discharge will be blocked, plugged or plated over to provide a physical barrier that will prevent discharging of mud.

The removal of plugs from drains following the use of NADF is controlled by a procedure and must be conducted under a Permit to Work authorisation.

Clean water, either from hazardous or non-hazardous source may be directed overboard if the effluent discharge is within environmental limits (monitored by the oily water discharge monitoring and alarm system), whilst remaining sludge and oil are directed to the necessary holding tanks for proper disposal either in the auxiliary boiler or taken onshore for treatment/ disposal.

Management

The DWF will have designated containment and bunding zones where oil products are used or stored. No wastes will be discharged directly via deck wash-down.

Bunded oil storage areas are directed to the oil/water settling system, where oil and water are separated. A skimmer collects oily residues from this separator system for disposal onshore. The water from the system is discharged overboard to MARPOL requirements (<15ppm oil-in-water) and continuously monitored by an approved Oil-in-water (OIW) meter which is calibrated on a routine basis. The oily water discharge is fitted with an alarm and automatic stopping device. Oil from the separator system is returned to shore for disposal. The records of oil disposal are maintained in the Oil Record Book.

The oily water system and meter are approved in accordance with MEPC.107 (49).

The oil/water settling system is routinely monitored and regularly maintained in accordance with manufacturer specifications.

Used lubricants will be stored in bunded areas aboard the rig and subsequently transported onshore for recycling or disposal at approved locations. Minor oil/lubricant spills will be mopped up with absorbent materials that will then be disposed of onshore as hazardous waste.

In non-drill floor areas, drainage is either to an oily water treatment system operated in accordance with MARPOL requirements or to a containment tank where the water is tested and assessed prior to discharge overboard. During periods of NADF use, the non-drill floor areas that may be exposed to NADF will be bunded to contain any NADF. The contents of these bunds will be periodically vacuumed to ensure good housekeeping.

Daily inspections will ensure that deck areas are clean of spillages and accumulations of oil/grease and chemicals, and that all spills and leaks are recorded / reported.

The drill floor drip pan encompasses the entire floor and has drains to a pollution tank where fluid is captured. Fluid will be directed to the shakers from the pollution tank when NADF is in use or discharged overboard when WBM is in use.

To ensure marine contamination from deck drainage in minimised, the following procedures and controls are required:

Chemicals, oils and wastes are stored in designated storage areas where appropriate spill clean-up materials (e.g. absorbents, containers) are maintained in accessible locations.

In the event of a chemical or oil spill, absorbents are used to remove spill material prior to any washing activities.

Absorbents will be readily available for small deck spillages. Biodegradable detergents will be selected for wash-down. Absorbent material, used for clean-up, is containerised and sent to shore as hazardous waste.

Bunding (temporary or permanent) is provided for those areas/activities where there is an increased risk of oil/chemical spill (e.g. fuel transfer).

Material Safety Data Sheets are available for all chemicals used on the MODU (which includes spill response requirements).

All effort is made to select chemicals of low environmental impact.;

The oily water discharged stream is monitored via an IMO approved and calibrated Oil-in-water (OIW) meter, which is alarmed to identify quality deviations and has an automatic shutdown.

The oily water system is routinely monitored and regularly maintained.

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

No adverse environmental effects are anticipated because of the low concentration of contaminants, minor quantities of overboard discharges involved and the likely localised zone of effect of any impact.

6.5.1 Equipment/ Machine Space Drainage

Activity

Equipment and machine spaces on the DWF are fully contained and have dedicated drains leading to the bilge water system for oily waste products. Oily residues collected in this system are containerised in transit tanks and returned to shore for disposal. Oily water from the system is treated to an oil-in-water concentration of 15ppm and then discharged to the marine environment.

In addition small quantities of hydraulic fluids may be discharged from the BOP hydraulic system or from the operation of Remotely Operated Vehicles (ROV). Hydraulic fluids used are biodegradable and of low toxicity.

Assessment

No significant environmental impact is expected from the disposal of oil or oily water from equipment/machinery space drainage because of the management controls in place. The environmental risk associated with this activity is assessed as inconsequential.

Any release of hydraulic fluids associated with operation of the BOP and ROV will be highly diluted and any effect restricted to the immediate vicinity.

Management

The current protocol for collection and treatment of machinery/equipment space drainage ensure that no oil is routinely discharged to the environment. Collected oil will be transported onshore as waste and disposed at licences waste disposal facilities. Each shipment of wastes to onshore facility will be accompanied by waste manifest and recorded in the shipboard Oil Record Book.

6.5.2 Hydraulic Releases from BOP and ROV Operations

Activity

The BOP control system is designed to release control fluids to the sea on stack operation. A full function test to close and open the rams and annulars will discharge approximately 1200L of hydraulic fluids. The hydraulic fluid used is rated “E” under the CEFAS (non-charm) classification scheme and is diluted to 1-2% with potable water for use. The fluid is biodegradable of low toxicity and will readily disperse following discharge.

Small quantities of hydraulic fluids may be discharged from operation of the Remotely Operated Vehicles (ROV). Hydraulic fluids used are biodegradable and of low toxicity and are expected to readily disperse on discharge.

In addition small quantities of methanol may be discharge/ released to the environment during hydrate dissolution.

Assessment

Any release of hydraulic fluids associated with operation of the BOP and ROV will be highly diluted and any effect restricted to the immediate vicinity. Given the low toxicity, biodegradability and the sparse benthic communities within the drill area the discharge of hydraulic fluids from BOP operations and ROV operations is unlikely to have any significant environmental effects.

Management

No specific management issues have been identified.

6.5.3 Discharge from Mud Tanks (following Cleaning)

Activity

The DWF will discharge small volumes of settled materials from the mud tanks and circulation system after tank cleaning. At completion of drilling at each well, the residual NADF contained within the mud tanks and circulation system will be returned to shore for treatment and reuse. Some small amounts will be discharged as tank washings at change over between NADF and water based muds.

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

To avoid the increased risk and manual handling issues, sedimentation from the tanks will be discharged directly overboard.

The removal of residual sediment from the DWF would require personnel (in full personal protective equipment) to enter a confined space from the top entry point of the mud tank and descend a ladder to the tank floor. Personnel would then be required to work around the fixed agitator in the mud tank and amongst the sediments on the floor of the mud tank. The entry to the tank is approximately 600mm x 600mm.

This phase of the tank cleaning process would require personnel to work within a confined space placing the sediment into buckets and hauling the buckets by rope to the top of the tank. ExxonMobil consider this to represent an increased risk to safety of personnel given the steep descent and ascent on the slippery surface.

Additionally, whilst appropriate risk management measures are identified and implemented through Job Safety Analysis, Confined Space Procedures and the Permit to Work System, emergency evacuation from the confined space is also considered to pose an increased risk to the safety of personnel.

Once the sedimentation is lifted out from the tanks, it is necessary for personnel to carry the sediment from the mud tank to the lay down area for the closed skips (used to transport the waste to shore). This is also considered to add unnecessary safety risks to personnel, particularly in light of manual handling and trip hazards

It is estimated that the volume of sedimentation requiring discharge overboard after cleaning for each well is approximately 5 m3 of residual muds.

Assessment

The drill fluids in the tank are insoluble and sink rapidly. They comprise of compounds with low toxicity with no demonstrated long lasting effect on benthic communities. Short term effects on abundance and bio-diversity are restricted to <200m from the DWF.

This activity presents a low environment risk based on the following;

No new chemicals have been introduced to the process and the solids consist of residual non-aqueous drilling fluid, barite, fine drilled solids, mud solids and surfactants which have been assessed previously as per ExxonMobil requirements (CHARM, OCNS rating where available).

The concentration of solids will be significantly reduced through dilution through the cleaning process prior to discharge and further dilution in the marine environment.

This activity is to occur on a limited frequency, approximately once at each well site.

Any discharge via the tank dump requires specific approval and a permit to work.

Management

As part of the cleaning process mud pits will be filled with seawater and surfactant (CHARM registered)), and agitated. Samples will be taken and evaluated to determine suitability for discharge (further dilution to be conducted if test results are unacceptable) to ensure that discharges to sea result in less than 10% residual NADF by volume.

ExxonMobil are installing a portable automated tank cleaning system on the DWF. The system is operated as a closed loop system. Many systems on offer only have sacrificial systems where all the wash fluid is discharged overboard or collected as slops (this generates a very large slop volume requiring disposal). The closed loop system allows the cleaning fluid to be reused thereby reducing waste volumes. The detergent cleaning fluid can be used for 10 cleaning cycles depending on the level of contamination.

To avoid the increased risk and manual handling issues, sedimentation from the tanks will be discharged directly overboard.

The removal of residual sediment from the DWF would require personnel (in full personal protective equipment) to enter a confined space from the top entry point of the mud tank and descend a ladder to the tank floor. Personnel would then be required to work around the fixed agitator in the mud tank and amongst the sediments on the floor of the mud tank. The entry to the tank is approximately 600mm x 600mm.

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

This phase of the tank cleaning process would require personnel to work within a confined space placing the sediment into buckets and hauling the buckets by rope to the top of the tank. ExxonMobil consider this to represent an increased risk to safety of personnel given the steep descent and ascent on the slippery surface.

Additionally, whilst appropriate risk management measures are identified and implemented through Job Safety Analysis, Confined Space Procedures and the Permit to Work System, emergency evacuation from the confined space is also considered to pose an increased risk to the safety of personnel.

Pit cleaning will be undertaken as per rig procedures and because of the safety and environmental risks a permit to work and Job Hazard Analysis (JHA) review must be completed before work commences. The discharge of residual mud on completion of drilling will be subject to the following management requirements and a specific work procedure will be developed as follows:

Fill pits with seawater and surfactant agitate and rinse the pit side walls. Evaluate samples to determine suitability for discharge (further dilution to be conducted if test results are unacceptable) to ensure that discharges to sea result in less than 10% residual NADF.

Use firewater hoses to fluidise remaining solids for overboard discharges until pits are clean.

All chemicals to be assessed for environmental impact prior to use (Environmental Performance Standard for Chemicals).

Obtain Company and Contractor supervisor approved work permit for each operation of mud tank discharge.

Physical barrier is to be in place to prevent discharging of mud where permit to work procedure incorporating supervisor signing has not been implemented.

Proposed NADF has been tested for toxicity and found not to be toxic.

6.5.4 Cooling Water

Activity

While at location, the DWF continuously uses seawater as a heat exchange coolant for machinery engines. The seawater is drawn from the ocean and flows through heat exchangers once, picking up heat, and is then discharged to the ocean. The seawater is segregated from all oil-services, preventing oil contamination of the cooling water discharge stream.

The DWF may utilise a small amount of biocide, assessed for its environmental impacts, which prevents marine fouling of heat exchangers. The cooling water is discharged from the DWF to the sea surface allowing for ready dispersion within the marine environment.

Cooling water, which is discharged below the water line, can enter the marine environment with elevated temperature of up to 15-20oC above that of surrounding waters.

Assessment

Elevated seawater temperature may cause a variety of effects on marine biota including behavioural changes (including attraction or avoidance), minor stress and potential mortality for prolonged exposure. Warm water is less dense than the surrounding seawater and it will rise and disperse near the sea surface. The cooling water plume is expected to approach that of the receiving water very rapidly within a few tens of metres from the discharge point (Swan et al, 1994) and the extent of impact is small, localised and affects species which could become entrained in the plume (e.g. plankton). On this basis, no significant environmental impacts are anticipated from this localised discharge and environmental risk is assessed as inconsequential.

Any biocides used in the cooling water system, while classified as toxic, are added in small quantities and are not expected to persist in the marine environment. Given the localised extent of impact and the highly dispersive environment, no significant adverse environmental impacts are expected and the risk is considered inconsequential.

Management

The use of biocide is maintained at minimum dosages necessary to maintain the cooling water system free of marine fouling.

During drilling, the seawater cooling system is segregated from all oil-services and therefore the potential for oil contamination of the cooling water discharge is very small.

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

Pump seals on cooling water pumps are regularly inspected and maintained for oil leaks.

6.6 Waste Management

Activity

Wastes that may be generated during the drilling activity include:

sewage and grey water;

equipment packaging materials – paper, cardboard, sacking, plastic, wood and metal;

domestic packaging (food and drink containers, etc.);

paints, fuel and lubricating oils;

domestic putrescible wastes; and

hazardous wastes.

The disposal of sewage, grey-water and food-scraps from the DWF will be in accordance with MARPOL Annex IV – Regulations for the Prevention of Pollution by Sewage from Ships and MARPOL Annex V – Regulations for the Prevention of Pollution by Garbage from Ships [Ref 43] which requires appropriate processing of waste prior to discharge to the marine environment.

Operation of the DWF will result in the generation of approximately 25,000 L/day of sewage and wastes from the kitchen, shower and laundry area (based on maximum personnel on board).

Assessment

Release of grey-water, food-scraps and sewage into the marine environment will increase nutrient availability and Biological Oxygen Demand (BOD) and potentially impact on the visual amenity around the discharge point. However, no significant impacts are expected from these discharges given the biodegradable nature of the waste, the small quantities released relative to the marine environment (hence localised), the lack of nearby habitats which might be affected by increased nutrient levels and the highly dispersive nature of the receiving oceanic environment. The environmental risk associated with this activity is assessed as inconsequential.

Chemicals intended for offshore discharge are addressed in Section 6.2 and are listed in Appendix 2.

Other chemical and solid wastes will not be discharged to the marine environment.

Management

Solid wastes, chemical wastes, sewage, grey water and food wastes generated on board the DWF and support vessels will be managed in accordance with MARPOL requirements via the ExxonMobil Waste Management Procedure, and the DWF Waste Management (HSE EMS 2.3.6.2) and associated procedures, or corresponding support vessel waste management procedures.

Sewage and grey water on all vessels will be treated by an approved facility (Type II Marine Sanitation Device) in accordance with MARPOL Annex IV or stored in a holding tank for disposal either on shore, or beyond 12nm while the vessel is proceeding at a speed of at least 4 knots. Between 3nm and 12nm from shore, sewage will be comminuted and disinfected prior to discharge and the effluent will not produce visible floating solids nor cause discolouration of the surrounding water.

Food-scraps will be collected and macerated to a particulate size of less than 25mm before being discharged to the marine environment below the water line or transferred to shore for disposal.

No sewage or food-scraps will be disposed within 12nm from land (applicable to support vessels).

Inspection and maintenance of each vessel’s sewage treatment system and food macerator will be included on the vessel preventative maintenance system and conducted on a regular basis to confirm operability and performance.

All other solid wastes and hazardous wastes generated on board will be segregated and stored in appropriate containers for disposal at appropriate onshore facilities.

Solid wastes will be segregated into waste streams and stored on-board in appropriate containers and covered where required. Solid and hazardous waste will be transported back to the mainland where they will be either recycled or disposed of at an approved landfill or other disposal site.

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

No adverse environmental effects on the marine environment are anticipated associated with the storage and handling of solid and hazardous wastes.

6.7 Introduction of unwanted aquatic organisms via ballast water and hull fouling

Activity

Biological fouling on vessel hulls has the potential to translocate non-endemic marine species into areas where they could displace native species, or interfere with ecosystem processes in other ways. Similarly, marine vessels can carry ballast water containing marine species that have the potential to threaten marine ecosystems where the ballast water is discharged. Most exotic marine pests introduced into Australian waters have distributions restricted to coastal habitats [Ref 11].

Like all marine vessels, the drill rig and support vessels will require ballasting and de-ballasting at certain times.

Assessment

Routine cleaning of the DWF and support vessels ensures that there are no introductions of non-endemic species on hulls and equipment.

The DWF and associated support vessels will not carry or discharge ballast water from any high risk ballast water areas during this campaign.

Management

The Australian Quarantine Inspection Service (AQIS) is responsible for the implementation of safeguards to minimise the risk of further introductions. Accordingly, AQIS has developed a Ballast Water Decision Support System (DSS) to assist in minimising the risk of further incursions of exotic species.

The Ballast Water DSS is used to determine the risk rating for each vessel entry into Australian ports, which then determines the management strategy for that vessel. The Ballast Water DSS is one of the ballast management options approved by AQIS under the Australian Ballast Water Management Requirements. The risk rating is based on a number of factors including the likelihood of target marine pest species being translocated in the vessels hold, the previous ports at which ballast water has been taken up and the likelihood of non-target marine pest species being translocated, and vessel specifications which may influence translocation via ballast water.

As part of the DSS process, all ships entering Australian waters are required to submit an AQIS Quarantine Pre-Arrival report for Vessels (Pratique) Form 12-48 hours before arrival. The data from these forms will be used as input to the DSS for determination of risk rating for the vessel. AQIS will then be in contact with the Ship’s Master with regard to treatment options if treatment is deemed necessary. Remedial actions may take the form of dry docking or where possible underwater cleaning of hulls prior to departure.

AQIS officers inspect the vessel and its records on arrival in Australian waters, which is prior to its arrival at the Jansz-Io drilling location.

The DWF and support vessels will adhere to these AQIS requirements in relation to ballast water to ensure ballast is managed satisfactorily. No ballast water will be discharged from internationally trading vessels inside Australian territorial seas (12 nautical miles) without express written permission from AQIS.

For this drilling campaign the DFW and support vessels will not be working in, and as far as practicable, will avoid marine protected areas.

No adverse environmental effects associated with ballast are anticipated, as ballasting operations will be discharged in accordance with regulatory requirements.

6.8 Interference with Commercial Fisheries

Activity

During the drilling of the Jansz-Io wells, the following vessels will be present in the Jansz-Io area:

the DWF, which will be on site for the duration of the drilling campaign;

support vessel standing by the DWF to provide safety support (at all times); and

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

supply vessel servicing the drilling DWF approximately fortnightly.

Assessment

The presence of these vessels could potentially interfere with shipping and fishing vessels, thus increasing the risk of collisions. However, the Jansz-Io region is located away from the main commercial shipping channels between North-Western Australian Ports (Port Hedland, Dampier) and Indonesia/ South East Asia.

The majority of effort from fisheries on the NWS is focused inshore of the proposed drilling locations, in waters of depth less than 100m (trap fisheries generally in less than 50m of water and trawl fisheries generally in less than 100m of water).

The presence of the drill rig is not anticipated to have any significant impact on commercial fishing activity, which is typically of low intensity in this area.

Petroleum Infrastructure Presence

The physical presence of subsea infrastructure (i.e. completed wellheads) represents a potential loss of access and snagging hazard to the fishing industry (post-decommissioning). However, the presence of wellheads provides hard substrate for marine organism colonisation that would not otherwise be successful in colonising the area. This is similar to the impacts which are found on subsea shipwrecks. The environmental impacts associated with the provision of artificial habitat are locally increased biological productivity and diversity.

The Jansz location is not heavily fished by commercial fisheries (refer section 4). Additionally methods used by commercial fishermen (‘trap’) lend themselves to working around hydrocarbon infrastructure.

Management

In accordance with maritime standards the DWF and support vessels will be appropriately illuminated, to reduce the chance of collisions and to ensure that it provides a safe work environment for crew and contractors.

Also under the OPGGSA, fishing vessels are excluded from the 500-m-radius safety exclusion zone around subsea equipment. A safety exclusion zone of 500m will also be established around the DFW vessels and maintained at all times. The potential impact of the loss of access to the area is very small in relation to the area still available for fishing.

At the end of field life the wells will be abandoned in accordance with OPGGSA requirements. At this time separate submissions will be made to the Authority by the Gorgon Project Operator requesting approval of the abandonment plan.

Pre-drilling consultation with relevant fisheries did not identify any potential conflicts with users. Continued ongoing communication with fisheries during drilling activities will enable the opportunity to manage and resolve any conflicts, should they arise. The residual risk to commercial fisheries as a result of the presence of drilling vessels is assessed as inconsequential.

6.9 Interference with Shipping

Activity

The Jansz-Io location is not located in a major shipping route (the closest major port to the location is Port Hedland to the south-east). It is possible that transient shipping traffic would move through the area en-route between southern Australian ports and areas to the north of Australia.

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

Figure 6-2 Shipping routes and ports in North West Region (GA, 2007)

*The Jansz-Io Location is shown by the green marker.

Assessment

The presence of the DWF and support vessels is not anticipated to have any significant impact on commercial shipping activity, which is typically of low intensity in this area.

While significant consequences may result from oil spills associated with a vessel collision, given the location of the drilling (away from commercial shipping lanes), the radio & radar communication methods adopted, the availability of an attendant vessel at all times and the rig/supply vessel illumination, the likelihood of such a collision occurring is rare and the environmental risk is assessed as inconsequential.

Management

Vessel Presence

A 500m safety zone will be gazetted under OPGGSA Section 329 around the DWF to reduce the risk of collision with passing vessels. This safety zone will also be notified to Mariners. Other control measures to prevent collision include appropriate navigation lighting and continuous radar/radio monitoring while the DWF is on location.

Any vessels contracted for the project will be required to comply with MARPOL requirements and other applicable maritime law, and will need to operate strictly in accordance with procedures for marine operations.

An emergency response/oil spill contingency plan will be specifically established, implemented and tested for the Drilling Campaign.

Infrastructure Presence

During the life of the wells, the wellhead will have a gazetted 500m safety zone preventing vessel encroachment on the subsea structure.

6.10 Interference with Recreational Users

No recreational fishing is known to occur in the deep water areas around the Jansz field. Recreational fishers are known to visit Barrow Island, the Montebello Islands and other surrounding islands.

The presence of the DWF is not anticipated to have any significant impact on recreational fishing activity, which is typically of low intensity in this area.

11500’0’E

2000’0’S

11000’0’E 11500’0’E

2000’0’S

11000’0’E 11500’0’E

2000’0’S

11000’0’E

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

6.11 Exhaust Gas, Fuel Use and Incinerator Emissions

Activity

The production testing flare and various power plant and machinery on board the drill rig will generate exhaust gases that will be released to the atmosphere. The volume of greenhouse gas (CO2) emitted from the drilling operation will be insignificant compared to Australia’s total annual emissions of approximately 560 Mt CO2 equivalent (2005).

The volume of fuel used to dynamically position the drill rig and support vessels will be in the vicinity of 100 m3 per day (approximately 65 m3 per day for the rig and 35 m3 for the support vessels).

Burning of waste materials in vessel incinerators, will not to be undertaken on the Deepwater Frontier or support vessels during the campaign.

Assessment

It is anticipated that there will be no adverse environmental impacts from the flaring during well testing as the well test is of a short temporal duration.

Most of the gaseous emissions will be in the form of carbon dioxide (CO2), although smaller quantities of other gases, such as oxides of nitrogen (NOx) and carbon monoxide (CO) will also be generated. Minimal quantities of sulphur dioxide (SO2) will be generated due to the sulphur content of the gas and diesel fuel.

Management

While emissions from diesel engines cannot be prevented, performance of internal combustion engines will be managed on preventative maintenance systems.

Low sulphur diesel fuel will be used where practicable. Vessel fuel oil will comply with requirements of MARPOL Annex VI Regulation 14 i.e. less than 4.5% sulphur content mass per mass.

Fuel usage will be recorded and reviewed regularly for any significant variations.

While incineration capabilities are available on the Deepwater Frontier it is not intended to conduct any incineration. In addition no incineration will take place on board the support vessels.

All sludge/ oily wastes (EPI classified Hazardous Waste material) will be appropriately stored on the Deepwater Frontier prior to transfer to shore for disposal. Wastes will be transferred to a licensed disposal facility (Toxfree at Port Hedland).

ExxonMobil is an active participant in the Australian Petroleum Production and Exploration Association (APPEA) Co-operative Agreement on abatement of greenhouse gas emissions and actively pursue greenhouse gas emission reduction opportunities and endeavour to keep contributions to greenhouse gas emissions to a minimum.

6.12 Acoustic Noise including Seismic Profiling

Ambient ocean noise as a result of wind and wave activities, have been assessed at 90 – 110dB re 1 Pa [Ref 13]. Avoidance or behavioural changes in marine mammals have been observed at thresholds of 120dB re 1 Pa or higher [Ref 7].

Toothed cetaceans (sperm whale, beaked whales, and dolphins) produce echo clicks that have the highest source levels of any recorded marine mammal sound ranging from 220-230dB re 1µPa-m at frequencies between 10-100kHz [Ref 21]. Baleen whales (e.g. Blue & Humpback) are considered the most sensitive of the marine mammals to marine noise due to their use of low-frequency signals (range: 12Hz-8kHz but predominantly <1kHz) for communication [Ref 44].

Turtle hearing is most sensitive in the frequency range of 100 – 700Hz [Ref 21]. Studies indicate that sea turtles begin to show behavioural responses to an approaching air-gun array at 166dB re 1µPa and avoidance around 166-176dB re 1µPa [Ref 17].

Toothed cetaceans that may occur in the area include family of beaked whales, sperm whales, pilot whales, and oceanic dolphins. Baleen cetaceans that may occur in the area include blue whales, minke whales, and humpback whales. The Jansz drilling area is not a recognised feeding, breeding or resting area for cetaceans, migratory birds, marine reptiles or migratory shark species however these types of fauna may migrate through the area on an occasional basis to their way to feeding and nesting areas.

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

Small aggregations of whale shark occur near the coast of central Western Australia each autumn particularly off Ningaloo Reef in March and April [Ref 18 and 42].

Activity

Major noise sources during drilling originate from drilling machinery, active drilling and support vessel activities. Typical noise levels produced from drilling campaign are detailed in Table 6.1.

The hours of drilling operation are as follows:

drilling will be conducted 24 hours/day while the rig is on location;

support vessel will guard the rig and will operate 24 hours/day; and

supply vessels will service the drill rig as needed. Supply operations will take approximately 12-24 hours to complete.

Equipment Noise

The DFW and support vessels will generate noise while drilling and through their movements and positioning. The greatest source of vessel noise will be generated from the DWF engaging its thrusters to maintain position. Studies of the radiating underwater noise generated from the thrusters and propellers of support vessels when holding position indicate highest measured levels of up to 182 dB re 1Pa with levels of 120 dB re 1Pa measured at 3-4 km [Ref 44]. In the Timor Sea, McCauley [Ref 44] measured noise levels of 146dBA re 1µPa from a semi-submersible MODU while the rig was not drilling and 169dBA re 1µPa when drilling. The maximum audible range for a semi-submersible MODU was 11km (ideal conditions while drilling) and only 1 – 2km while not drilling. In the Otway Basin, Woodside (2002) measured maximum broadband noise of 145dBA re 1µPa emitted from a semi-submersible MODU at a distance of 5.1 km during a 32-days drilling period [Ref 13]. Drilling noise was dominated by sharp tones (<100Hz) with little high frequency noise. These noise levels are comparable drill ships whose noise levels whilst drilling are in the range of 171-182 (refer to Table 6-3).

The sound levels and frequency characteristics of underwater noise produced by support vessels are related to ship size and speed, and the particular activity being conducted by the vessel. Under normal operating conditions when the support vessel is idling or moving between sites, the support vessel would be detectable only over a short distance. However, when the vessel is holding its position using bow thrusters and strong thrust from its main engine, noise may be detectable up to 20km or more although this range of audibility will be reduced under windier (noisier) conditions [Ref 13]. While support vessel activities extend the area of impact, these activities typically occur for approximately 2% of the total drilling duration [Ref 44].

Table 6-3 Typical noise levels associated with drilling activities

Vessel Source pressure level

(dB re 1 Pa@1 metre) Dominant frequency

range (Hz) Hearing range - toothed whales

Hearing range – baleen whales

Drill Ship (during drilling))

174-182 45-1780 ×

Support

vessel

110 – 135 (without thrusters)

121 – 146 (with thrusters)

20 – 1000

20 – 1000

×

×

Helicopter - <500 ×

Fishing Trawler( 158 100 x

Noise emitted from helicopter operations is typically below 500Hz. Sound pressure in the water directly below a helicopter is greatest at the surface but diminishes with depth. Reports for a Bell 214 (stated to be one of the noisiest) indicated that noise is audible in the air for 4 minutes before the helicopter passed. The Helicopter is audible underwater for only 38s at 3m depth and 11s at 8m depth [Ref 13].

Seismic Profiling

There are no activities planned for the Jansz-Io Drilling campaign which will require an airgun source.

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

Assessment

Equipment Noise

Cetaceans and marine reptiles are known to alter behaviour as a result of noise disturbance [Ref 26] and are likely to avoid the immediate vicinity surrounding the DWF due to continuous noise impacts from equipment. While evidence indicates that noise may arouse cetacean’s curiosity, they are known to practice avoidance if the noise generation is found undesirable [Ref 8 and 44].

As the aggregation area for whale sharks is more than 330 km from the drilling area and a search of the SEWPAC EPBC Act Database did not identify whale sharks in the vicinity of the Jansz-Io well area, the drilling campaign is unlikely to affect this species.

There is unlikely to be significant adverse effect on other marine fauna from drilling the Jansz-Io wells as the proposed well location is not in known feeding, breeding or aggregation areas for marine fauna, nor does the drilling programme overlap migratory routes of humpback whales [Ref 40].

Guidelines published by DEWHA indicate that the level of noise that may cause interference to cetaceans has been set at 150 db. McCauley et al. [Ref 44] identified that noise levels from an operating drilling rig were in the vicinity of 117 db (125 m from the wellhead) and noise levels from tender vessels associated with the drilling rig were approximately 137 db (405 m from the wellhead).

Given that the noise and vibration levels from the drilling activity are less than those expected to cause interference, it is assessed that drilling activities are likely to have negligible impact on migratory whales and turtles and on commercially important fish populations [Ref 52].

It has been observed that birds habituate well to routine noise [Ref 52], however as no known rookeries exist in the drill area it is considered that noise impacts to birdlife will be minimal.

The overall environmental risk posed by noise emitted from the DWF, associated vessels and helicopter is assessed as inconsequential, given the presence of cetaceans, migratory birds and marine reptiles in the permit area will only be occasional and the given the adopted controls measures in place for mobile offshore drilling units.

Management

Mobile noise sources (support vessels and helicopters) have the ability to divert course and directly approach marine fauna which may cause them distress. To control interactions between cetaceans and vessels (including the possibility of vessel strike)/helicopters, mandatory compliance with the requirements of the Australian National Guidelines for Whale & Dolphin Watching [Ref 26] is required. Measures taken will be in accordance with Regulation 8.03 of the Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act) (Cth) which notes that:

“Vessels and support vessels will maintain a 300m standoff distance and must move at a constant slow speed to sustain that distance if the whale is approaching the vessel.”

For aircraft, Regulation 8.07 notes:

“Airlines shall not operate at a height <1000ft within a horizontal radius of 300m of a whale nor helicopters <1650ft or within a horizontal radius of 500m of a whale.”

Where possible, avoidance measures such as altering speed or course will be implemented should listed marine species be sighted.

Personnel working offshore will be required to notify sightings of any protected marine fauna observed. Observations will be logged and reported using the dedicated report form and forwarded to SEWPAC. No fishing from the installation vessels will be permitted by project personnel.

6.13 Accidental Discharges

6.13.1 Oil Spill Resulting from Loss of Well Control or Collision with Other Vessel, or structure

Activity

The campaign will be accessing gas fields (with minor amounts of associated liquids). Relevant scenarios for this campaign include loss of well control, uncontrolled hydrocarbon (marine grade diesel) releases resulting from vessel collision, and pipe / tank / hose rupture during refuelling.

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

Assessment

During drilling, activities with the potential for hydrocarbons to enter the marine environment include:

Fallout from Production Testing: Spill sizes are typically small (<600 litres) and based upon North Sea and Gulf of Mexico databases have a low probability of occurring (1 in 1.5 million).

Refuelling activities: Spill volumes are generally limited to the volume of the hose, minimised by automatic pump shutdowns and safety valve closure. Generally spills from a rupture of a fuel transfer hose, amount to no more than approximately 300 litres.

Rupture of fuel storage on support vessel: From international databases, the overall probability of a large oil spill incident (of size 80m3 - typically the rupture of a diesel tank on the support vessel) is approximately one in 14,400 during a 25 day drilling period (EPA, 1997). The risk from attendant vessels is considered to be low, as the two support vessels with AHTS capability selected to support the campaign and act as supply vessels will be suitable for use in the offshore petroleum industry and will be operated by crews familiar with offshore MODU operations.

Rupture of NADF storage tanks or an uncontrolled release of NADF during drilling operations. The base fluid component NADF oil has been selected specifically to be a low toxicity CHARM rated substance so that if a spill did occur it would have minimal impact on the environment. The DWF has also been surveyed by specialist drilling environmental waste engineering organisation to assess the rig’s capability to successfully handle, contain and circulate NADF. The survey also included an assessment on the rigs solids control equipment suitability to ensure that all systems on the DWF are ready to receive, handle and contain NADF and base oil to minimise the risk of discharge to the environment [Ref 50].

Transfer of bulk NADF (predominantly Saraline 185V and approximately 96% CHARM rated Gold or Silver OCNS D or E) by hose from the support vessel to the DWF. Bulk transfers to the rig are undertaken using strict procedures which include the following controls:

i. Daylight transfers (night transfers by exception and under strict additional controls)

ii. Suitable weather conditions

iii. Observers to watch for failures

iv. Dry break couplings

v. Automated shut off pumps

vi. The volume being transferred is measured and monitored from the pump room where any loss will result in a corresponding loss of pressure. The engineer would see the loss of pressure and instruct pumps to be stopped.

Given these controls measures, in the event of a failure occurring during transfer operations the likely volume of liquid lost would equate to that of the hose volume (estimated at 101L (0.6 bbls) for a 30m (90 ft) hose).

Rupture of the DWF fuel tank as a result of collision with a vessel: The potential for collision with other vessels is limited as the Jansz-Io wells are located outside of the main shipping lane. Additionally, while on location, the DWF diesel tanks are elevated significantly above the sea surface making this spill scenario not credible. In addition the fuel tanks are double hull design reducing the risk of spillage.

Well Blow-out: The likelihood of a significant oil spill due to loss of well control is low as there are multiple levels of well control measures which will be implemented as described in Section 3. No well specific characteristics, changes or activities have been identified that would indicate a higher risk of blow-out. In addition the Jansz-Io hydrocarbons are primarily gas with less than 0.0001% liquid component (gas to oil ratio (m3/m3) of 35,213:1).

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

Riser emergency disconnect due to loss of Dynamic Positioning. The likelihood of a significant oil spill due to loss of positioning is low as there are multiple levels of control measures including redundancy in the positioning system. In the event that an emergency disconnect is required the total volume of the riser would be lost amounting to approximately 700bbls (111m3) of NADF.

In the event of an oil spill, the greatest potential impact from Jansz-Io drilling and vessel activity is contaminating coral reefs and island shorelines. The potential for oil to be transported from the Jansz-Io drilling location to reefs or shorelines is dependent upon the volume spilled, its weathering rate, and the influence of wind and tidal conditions.

Drilling was undertaken in late 2002 for Jansz-2 and was undertaken between April and September 2003 for Jansz-3. Results from the modelling showed that there is very low risk of exposure to any shorelines or emergent reefs within the region [Ref 5]. Two spill scenarios were modelled: a 500t 2-hour diesel spill and a 1000t 12-hour light crude oil spill to represent respectively worst case spills from the service vessel and the drilling operation.

Consequences of such a spill will be limited as over 90% of the spill will evaporate naturally or disperse into the water column in a time frame of between several hours to several days depending on the size of the spill. Given the safeguards in place, effects on marine resources are likely to be localised and short term. Natural biodegradation of any diesel fuel that finds its way into the water column is anticipated to be rapid and complete.

In 2011 subsequent stochastic oils spill modelling was conducted also by APASA for a diesel spill equivalent to the largest fuel tank on a supply vessel (250,000L) and an 11 week continuous seabed blowout scenario using gas specifications from the Jansz-Io reservoir [Ref 6].

The main findings of this modelling study were:

Large scale offshore drift currents will have a large influence on the trajectory of surface films and will control the trajectory of oil that is entrained beneath the water surface.

Interactions with offshore eddies and prevailing winds will add additional variation in the trajectory of the spilled diesel and in the case of the 11 week blowout scenarios, marked variation in the prevailing drift current and wind conditions would be expected over the duration of the release. This will increase the spread of condensate during any single event.

For simulations of the 80,000 L and 250,000 L diesel spills, modelling indicated very low probabilities (< 1%) of surface or entrained diesel > 0.15 g/m2 arriving at any adjacent shorelines during any seasons.

The discharge conditions assumed for the seabed blowout scenario are expected to result in the break-up of condensate into small droplets (~ 10 to 50 μm range) that are expected to take an extended time to rise to the surface and may become trapped by density layers in the water column. Under these circumstances, surface slicks/films would represent a small proportion of the mass of oil that is released.

Stochastic simulation of the 11 week subsea blowout indicated low probabilities (< 1%) of surface-bound condensate > 0.15 g/m² arriving at any of the surrounding shorelines during any seasons.

Entrained condensate has the potential to drift long distances with the offshore drift currents, with the highest probability of affecting waters close to shorelines in Summer, Autumn and Winter.

The modelled estimates of entrained oil drifting towards the shoreline vary with the season and with the threshold concentration levels used. At conservative concentrations of >10ppb (at least short-term 1 hour minimum) and in the season where drift currents are most likely to migrate the entrained oil to shore (Autumn) the sections of coastline around the North West Cape are indicated to have a moderately high probability (up to 50%) of being affected. In the same season but using a higher threshold level of >200ppb, the probability drops to 10-20%. During the Spring when migration to shore is least likely the probabilities for reaching these shorelines are 2% for the >10ppb threshold and <1% for the >200ppb threshold.

The minimum period of time for the entrained oil to reach the shoreline in Autumn (the mostly likely season for migration to shore) at any concentration (even less than 10ppb) is

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

estimated at 74 days. This is indicative of the response time that would be available for shoreline protection measures to be put in place.

The thresholds for contact used in this study are indicative only and do not imply impact will occur. Definitive thresholds for impact would need to be based on tests of the sensitivity of organisms occupying the adjacent habitats with the specific condensate mixture, after weathering under realistic conditions.

One implication of the relatively small size of condensate droplets that are indicated by this study is that the dissolution of soluble compounds from the condensate should be relatively rapid, with the highest dissolution rates occurring initially, associated with the turbulent plume. The more volatile and toxic, aromatic compounds would undergo dissolution leaving the remaining volumes of entrained oil to be composed of, less volatile, longer carbon chain alkanes. In addition, the relatively long durations that were indicated for oil to drift onto shorelines (75 days or more) from the blowout scenario indicates that some level of bio-degradation would occur, which would also target the more volatile, more toxic shorter-chained hydrocarbons [Ref 10]. The level of biodegradation would also depend on the composition of the oil where non-persistent oils (such as condensate) will degrade at a much faster rate than persistent oils. The impact is that the remaining entrained oil is less toxic and less biologically available if it reaches the shoreline.

The modelling also indicated that the condensate, which has a low viscosity, would tend to spread rapidly when it did reach the surface. This implies that entrained oil that surfaces at a long distance from the discharge source would tend to present as thin patches of sheen. The low residual (i.e. non evaporative) component in the fresh oil (0.5%) indicates that this oil sheen should also evaporate rapidly (within hours) when eventually exposed to the atmosphere, so that significant accumulation on shorelines is unlikely, if the sheens do drift onto a shoreline.

Sensitivity testing for the size of the droplets indicated that droplets one order of magnitude larger would result in a significant increase in the surfacing rate, and in turn, the proportion that will evaporate from the surface.

The fate of the released condensate from an 11 week continuous blowout scenario is largely dependant on the conditions at the time. The results of the modelling are based on highly conservative measures. The occurrence of such an event is considered to be unlikely given the well control measures in place as discussed below.

Management

Well Control

Well control measures to be implemented for this campaign are described in Section 3.

Notification

External stakeholders have been informed of the Campaign activity through a consultation programme. The Australian Maritime Safety Authority will be notified and notices will be provided to mariners detailing the location of the Transocean DWF. A ‘Notice to Mariners’ will be issued prior to the commencement of drilling.

Environmental Management Systems

DWF drilling activity will be managed in accordance with pollution prevention strategies and hazard communication planning as outlined within Transocean HSE Management System, a fully integrated health, safety, environment and quality management system. The DWF will maintain an Environmental Aspects List (HSE EMS 2.3.6) specifically addressing potential pollution sources. Spill prevention controls include Inspection/ audit procedures that address housekeeping, leaks/spills, and storage areas and HSE EMS Marine Operations Procedures Fuel Oil Transfer Procedures.

DWF operations will be conducted within a framework of environmental awareness training, routine inspections, job safety analysis and incident reporting.

The DWF and support vessel OSCP / SOPEP will be used in the event of a minor chemical or hydrocarbon spill on the DWF or Vessel. For significant spills, the spill response arrangements detailed in ExxonMobil Emergency Response Manual will apply.

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

The content of these documents will be introduced as part of the induction process for personnel on-board the DWF, and copies will be made available to crew members prior to the commencement of any work.

Campaign Specific Oil Spill Contingency Plan

Whilst the occurrence of such an event is considered to be unlikely, an Oil Spill Contingency Plan has been developed to meet the requirements of Section 14(8) of the Offshore Petroleum and Greenhouse Gas Storage (Environment) Regulations, 2009 and to respond to such an event [Ref 30]. The plan describes the full range of response options in place to mitigate environmental impact with priority given to protecting shorelines.

ExxonMobil standard response strategy matrix identifies actions in the event of different levels of oil spills. Broadly, it provides that a spill will be dispersed, recovered, sensitive areas protected and a beach clean-up initiated as necessary. Priorities are to stop the discharge, notify relevant personnel/agencies, evaluate the spill characteristics, predict movement and estimate effects on sensitive areas.

In the event of an ExxonMobil related spill offshore, the response would generally consist of the following steps where applicable:

Contain oil and recover at source if possible.

Monitor movement.

If oil is not being dispersed naturally, disperse by propeller agitation by boats and/or chemical dispersants after seeking necessary approvals.

Monitor shore-bound oil and protect endangered areas, in order of sensitivity. Consider/determine wildlife at risk; liaise with wildlife rescue authorities. The OSCP references the use of OilMap spill trajectory modelling or vector additions to predict the movement of an oil slick and facilitate appropriate response measures.

Skim oil pooled on coast.

Clean up shoreline.

Restore shoreline.

Dispose of all contaminated materials appropriately.

Terminate response.

Review plan. Offshore supply vessel(s) would be deployed to respond to the spills which have spray capabilities. Dispersants, if approved for use by the designated authority, would be sourced from existing industry stockpiles through the Australian Marine Oil Spill Centre (of which ExxonMobil is an active participant). In addition to AMOSC, ExxonMobil has access to additional oil spill response equipment and resources from ExxonMobil’s Regional Core Team and international industry stockpiles in both Singapore and United Kingdom.

Dynamic Well Kill Plan

In the unlikely event that an uncontrollable hydrocarbon release should occur whilst drilling/completing a Jansz-Io development well, a relief well would be required to control the flowing well. Sophisticated computer simulations have been conducted to model various release scenarios. The “worst-case” release event assumes the blowout preventer (BOP) was absent and unrestricted hydrocarbon flow occurred from the Jansz-Io sandstone reservoir through large bore tubulars to the seafloor. This scenario would result in very significant hydrocarbon flow to the seafloor.

The relief well simulations revealed that a sole large-bore relief well, positioned to intersect the flowing well at the lower-most casing shoe, would be sufficient to dynamically kill the flowing well. The well interception methodology/technology is well-proven and the required tools are readily available.

A study specific to the such a scenario at the Jansz-Io reservoir has been conducted to understand the process and all aspects of a dynamic kill plan including the required assets, resources, readiness and sequencing involved [Ref 56]. This plan would be enacted if an uncontrollable hydrocarbon release occurred enabling the fastest possible response to minimise the volume of hydrocarbon released.

If the DWF was unavailable to drill the relief well, a high specification floating MODU would be mobilized. In addition, several support vessels would be mobilized to provide high pressure pumping and fluid

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

storage capability. These vessels could be either locally available units retro-fitted with the required systems or purpose-built vessels mobilised from outside Australia.

Should any oil/fuel/chemical spill occur during drilling, the (actual and potential) impacts associated with such a spill will be managed by implementation of the OSCP. The selection of an appropriate response strategy for the control and treatment of a spill will depend on a number of factors, such as prevailing weather, size and type of spill and the migration of the spill.

6.14 Environmental Risk Summary

The Campaign is considered typical of those undertaken by the DWF. No extraordinary aspects, hazards or risks were identified during planning for the campaign.

The Campaign will have a limited localised and temporary impact over the Commonwealth marine area due to the nature of drilling activities. The activities associated with the project are considered unlikely to have a significant effect on the environment for the following reasons:

Threatened species listed under the Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act) and other marine species may pass through the project area but the operations will not give rise to impacts on habitat, migratory patterns or routes that are critical for their survival.

The physical footprint of the DWF contact area is relatively small and any disturbance that occurs around this footprint is likely to be temporary and localised.

Environmental management processes and procedures have been formulated in accordance with industry and company standards and will be adhered to throughout the drilling activities.

Control measures have been put in place to prevent to reduce the risks of environmental harm to a level that is ALARP.

Overall, the campaign represents a small addition to the existing North West Shelf oil and gas production infrastructure and will have minimal incremental environmental impact.

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

7 PERFORMANCE OBJECTIVES, STANDARDS AND CRITERIA

7.1 Environmental Goals

This section presents a summary of the environmental objectives that ExxonMobil has set for the Jansz-Io Drilling Operation, the standards that ExxonMobil has adopted to meet these objectives, and the criteria by which ExxonMobil will measure its performance against the stated objectives.

The environmental performance measures developed for the Campaign are:

No reportable spill of hydrocarbon or chemicals to the environment (as per r. 26 of the OPGGS (Environment) Regulations, 2009).

Compliance with applicable environmental legislation.

7.2 Performance Measures

In order to achieve these objectives, the following environmental requirements apply to the project:

In addition to the pre-start inspections that have been conducted, both ExxonMobil and Transocean will implement inspection and audit programmes during the operational phase to ensure compliance with ExxonMobil OIMS and Transocean Company Management System (CMS) requirements.

All project personnel will undergo environmental awareness training as part of their project induction.

All operating equipment is to be maintained in good working condition in compliance with an appropriate inspection, testing and maintenance programme.

Emergency response training and preparedness is to be tested prior to the commencement of drilling operations.

This approach applies to all environmental risks and effects associated with the Jansz-Io Drilling Campaign. Table 7.1 summarises the performance objectives, standards and criteria for the Jansz-Io Drilling Campaign.

7.3 Review and update of the Environment Plan

Where changes to this EP resulting from developments or intended actions have the potential to alter the previously accepted level of environmental risks and impacts, the regulator’s consent will be sought before implementing changes in accordance with the OPGGS (Environment) Regulations, 2009 (Cth).

In the event that a new activity is planned, drilling methodologies vary from those described in this EP, or if a new significant environmental effect is identified, this plan will be revised and resubmitted to the DMP Where operator wishes to carry out any activity other than in accordance with this EP, a revised plan will be submitted to the Minister (or delegate) for approval in accordance with EPBC Reference: 2005/2184, condition 6.

At the completion of the drilling campaign, a review will be conducted to determine:

The effectiveness of control measures.

Improvements in procedures or practices for future drilling campaigns.

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

Table 7-1 Summary of Performance Objectives, Standards and Criteria

Standards Criteria Frequency/Comment Responsible

Physical Presence

Performance Objective: Limit the impacts of the physical presence of activities on the marine environment, and nearby fishing/shipping operations.

DEWHA Cetacean interaction guidelines [Ref 24]

Interactions with cetaceans will follow SEWPAC cetacean interaction guidelines During drilling activities Offshore Installation Manager (OIM)

ANZECC Interim Ocean Disposal Guidelines (Section 2.2 “Site Selection, Management, Environmental Assessment and Monitoring”) [Ref 3]

Functional lighting in place on MODU and other vessels. Maintenance programmes ensure lighting operating correctly

Prior to start of drilling activities OIM

Code of Environmental Practice [Ref 8]

Mariners notified of activity via AMSA Prior to and during drilling and installation activities

OIM

ExxonMobil Environmental Policy and OIMS Requirements

Expectations communicated and understood Prior to start of drilling activities OIM

Auscoast/AMSA requirements Vessel interactions in the field logged As required OIM

Location of well and timing of activity avoids peak humpback migration pathways and periods

Prior to start of drilling activities Drilling Operation’s Superintendent

DMP Guidelines for drilling mud selection [Ref 27]

Audit verifies that a dynamically positioned drill rig is used, as discussed in this EP

Drilling Operation’s Superintendent

Compliance with DMP guidelines for drilling fluid selection Prior to start of drilling activities Drilling Operation’s Superintendent

Operations carried out in a manner that does not interfere with navigation to a greater extent than is necessary

Throughout drilling activities OIM

AMSA notified of drilling location and timing of drilling Prior to start of drilling activities Drilling Operation’s Superintendent

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

Table 7.1 Summary of Performance Objectives, Standards and Criteria (cont’d)


Greywater, Sewage and Putrescible Waste

Performance Objective: Limit the potential negative effects of greywater, sewage and putrescible waste discharges on water quality

Operating Procedures and Maintenance Management System

Operating and maintenance procedures exist and are followed for greywater, sewage and putrescible waste treatment

Periodically Supply vessel’s Maintenance Supervisor


Water quality trends, chemical usage and spill related incidents are logged Periodically ExxonMobil Drilling Supervisor

MARPOL Regulations, Annex IV (Prevention of Pollution by Sewage from Ships) (as adopted by the International Maritime Organisation (IMO) [Ref 43]

Sewage treatment units on-board DWF and supply vessels are maintained as part of routine maintenance

Ongoing Supply vessel’s Maintenance Supervisor

ANZECC Water Quality guidelines for Fresh and Marine Waters [Ref 4]

Annual audits will be conducted to verify that the grey-water sewage and putrescible waste systems are operating as required. This will include verification of maintenance records.

Clean water either from hazardous or non-hazardous source may be directed overboard if the effluent discharge is within environmental limits (monitored by the oily water discharge monitoring and alarm system), whilst remaining sludge and oil are directed to the necessary holding tanks for proper disposal either in the auxiliary boiler or for transport to shore for disposal.

Throughout drilling activities OIM

MAROL Regulations, Annex IV, 73/78 (Prevention of Pollution by Sewage from Ships) (as adopted by the International Maritime Organisation (IMO) [Ref 43]

Waste is macerated/ground to a particle size <25 mm prior to discharge to the sea

Ongoing OIM

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development



Solid Waste and Hazardous Waste

Performance Objective: Avoid/manage the effects of hazardous, liquid and solid wastes to ALARP

MSDS Sheets and Instructions Inventory is kept showing that spent oils and lubricants, and solid wastes are being containerised and returned to the mainland

Ongoing OIM


Personnel are aware of housekeeping requirements via inductions and updates/reviews

Ongoing OIM

Documenting, tracking, and segregation of hazardous wastes from other streams of operational wastes as well as their proper storage and handling

Ongoing OIM

Inventory exists of all chemicals to allow sufficient and appropriate recovery materials to be on hand in the event of a spill (i.e. MSDS sheets, labelling and handling procedures)

Ongoing OIM

Logs to show biodegradable detergents used Ongoing OIM

OPGGS (Env) Regulations, 2009 Compliance with legislation and procedures regarding housekeeping Ongoing OIM

Ballast Water

Performance Objective: Prevent the introduction of foreign organisms into Australia from overseas.

2001 AQIS Australian Ballast Water Management Requirements. Ballast Water Management System [Ref 9]

No items on board MODU or supply vessels that contravene Australian Quarantine Regulations

Ongoing OIM


Supply vessels will comply with AQIS Ballast Water Guidelines Ongoing OIM


Vessels entering Australia will clear customs before proceeding to site Ongoing OIM

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development



Bilge Water

Performance Objective: Avoid / reduce negative effects on water quality


Oil and chemical spills are cleaned up and residues are sent to slop tanks As required OIM

ExxonMobil OIMS and Environmental Policy

ExxonMobil Waste Management Procedure

Oil content of ballast water on supply vessels is monitored and complies with legislation

Regularly Vessel Master/Captain

OPGGS (Env) Regulations 2009 No process drainage or tank cleaning fluids will be drained overboard Prior to start of drilling OIM

MSDS instructions Drainage products are sent to the slops tank for settling and processing (as necessary) prior to discharge

Ongoing OIM

Atmospheric Emissions of Exhaust Gases and CO2

Performance Objective: Limit exhaust emissions including CO2


Monitoring and logging of fuel usage. Report to ExxonMobil Daily OIM

Generators, boilers and other equipment serviced and regularly maintained. Periodic reviews conducted of maintenance records and adherence to procedures related to power generation equipment


G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development



Subsea Gas Release

Performance Objective: Prevent occurrences of subsea blowouts resulting in gas release

ExxonMobil OIMS

ExxonMobil Well Control Manual and BOP Equipment Standards

MODU subsea BOP will be inspected and tested as required

Regular BOP drills will be held

Prior to start of drilling activities and periodically as required

Drilling Operation’s Superintendent

Ozone Depleting Substances

Performance Objective: Prevent releases of ozone depleting substances


No release of refrigerant gases As required Supply vessel’s Maintenance Supervisor


Monitoring and reduction of fugitive losses from systems Ongoing OIM

Where possible, no halon or CFC based systems will be selected Prior to start of drilling activities OIM

Environment Protection (Ozone Protection) Policy 1993, Sections 2, 26 and 33 [Ref 28]

Refrigerant gases are recovered when maintaining refrigeration, air conditioning and fire suppression systems and disposed of onshore via licensed disposal agents

As required Supply vessel’s Maintenance Supervisor

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development



Spillage or Inadvertent Release of Diesel Fuel/ Other Hydrocarbons

Performance Objective: Reduce the risk of diesel spills from the supply vessels or vessels in the field


Reporting of all spills to ExxonMobil and those greater than 80L to DMP and NOPSA

As required OIM

Inspection of fuel tanks /hoses undertaken as part of planned maintenance Ongoing Supply vessel’s Maintenance Supervisor

Hoses/fittings/connections are maintained and inspected as part of planned maintenance on the supply vessels


Design and construction of supply vessels diesel tanks reviewed and certified by independent agency

Prior to start of drilling activities OIM

Diesel refuelling/ transfer is conducted in accordance with ExxonMobil procedures and, if occurring within the Port of Dampier, those of DPA

Each fuel transfer operation OIM

Records kept of all refuelling operations Ongoing OIM

Fuel handling and storage procedures are in place and followed Ongoing OIM

Refuelling operations are not undertaken in darkness or unacceptable sea state Ongoing OIM

Hydrocarbon oils are stored in bunded areas on board supply vessels Ongoing OIM

Well testing and cleanup; minimise spills of unburnt oil

Gas testing and low likelihood of significant spills. Start of testing during daylight to allow visual inspection

Ongoing OIM

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development



Chemical Releases

Performance Objective: Reduce the risk of adverse effects to marine ecology from a chemical release

Code of Environmental Practice (APPEA, 1996).

Drill mud eco-toxicity properties are reviewed prior to selection Prior to field operations SHE Manager


Antifouling paints on vessels comply with legislation Ongoing OIM

Appropriate type and adequate quantities of absorbent material and spill cleanup equipment available on board the DWF, supply vessels and other vessels

Ongoing OIM

The planned NADF ROC discharges to the environment meet the following characteristics:

1. NADF ROC will be less than 10% for each of the 17-1/2”, 12-1/4”, and 8-1/2” x 9-7/8” hole sections, based on cuttings generated in each section.

2. NADF ROC (including residual NADF from conditioning) will be less than 10% for the combined 17-1/2”, 12-1/4”, and 8-1/2” x 9-7/8” hole sections for each well.

The NADF will be conditioned to remove fine particles generated in previous hole sections in preparation for completion operations. Solids and the residual NADF discharged during this activity will be allocated back to the 17-1/2”, 12-1/4”, and 8-1/2” x 9-7/8” sections based on the relative volume of cuttings generated in each section (for each well).

The approximate distribution of cuttings volume by hole section for the Jansz wells is shown below (percentages vary depending on measured depth of well):

1. 17-1/2” hole: 65-80%

2. 12-1/4” hole: 15-25%

3. 8-1/2” x 9-7/8” hole: 5%-10%

Ongoing OIM

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

8 IMPLEMENTATION STRATEGY

This section details the environmental management strategies and procedures that will be in place for the Jansz-Io drilling operation. These include responsibilities, training, reporting frameworks, mitigation and response activities, and monitoring and auditing procedures which are intended to reduce environmental risk to as low as practicable and to ensure that environmental performance criteria are met. Contractors will also be required to have in place formal written systems, practices and procedures for the management of SHE matters on their vessels including emergency response and oil spill response procedures.

As delegated Jansz-Io Work operator under the UUOA, acting on behalf of the parties to the UUOA and Chevron in Chevron’s capacity as the proponent of EPBC 2005/2184 and operator of the Jansz-Io production licences WA-36-L, WA-39-L and WA-40L, ExxonMobil will ensure that its personnel and contractors comply with environmental and regulatory requirements appearing in the OPGGSA, EPBC Act, this EP and other relevant legislation and company policies to reduce environmental risk to as low as practicable and to ensure that environmental performance criteria are met.

The environmental goals for this Campaign include:

Minimise the impact of activities on the marine and atmospheric environments.

Compliance with applicable environmental legislation.

Provision of effective emergency response management.

The DWF operator, Transocean, has an environmental objective to reduce unintentional discharges, which is measured annually based on frequency and volume. The target is improvement over the previous year’s performance in both categories and is monitored through compilation and review of quarterly reports submitted by all rigs to the parent company in Houston.

8.1 Systems, Practices and Procedures

This project is being implemented under the umbrella of the ExxonMobil Environmental Policy (Appendix 3), which the drilling contractor must abide by. The drilling contractor will also be required to have in place formal, written systems, practices and procedures for management of SHE (and emergency response including oil spill response).

Transocean have a legal responsibility as the nominated Facility Operator of the Deepwater Frontier to ensure that all activities undertaken on the DWF is conducted in a safe manner and that the risks associated with the work activity are managed to ALARP. In order to achieve this Transocean have in place a comprehensive Health Safety and Environmental Management System (HSEMS) and Risk Management process.

Transocean will ensure that all activities undertaken on the DWF are conducted and managed under the Transocean HSEMS and all personnel including third party contractors will be provided with induction training into the HSEMS system prior to undertaking work on the Deepwater Frontier.

These systems, practices and procedures will be reviewed and determined whether they are acceptable by ExxonMobil prior to commencement of operations. An ExxonMobil representative will accompany the DWF for the duration of the drilling activity.

As delegated operator of the permit area (acting on behalf of the parties to the UUOA), ExxonMobil will ensure that its personnel and contractors comply with all regulatory requirements of the OPGGSA, EPBC Act, this EP and other relevant legislation, as listed in Section 2.

ExxonMobil’s equivalent to the Transocean HSEMS is the proprietary OIMS as described in paragraph 1.8. This like the Transocean HSEMS provides for all the standard recognised requirements of safety management systems [Ref 29].

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

Key aspects of ExxonMobil environmental management strategies include:

ExxonMobil OIMS and supporting documentation, this EP and associated OSCP.

Transocean Vessel Safety Management System (part of the drill rig’s Vessel Safety Case).

The Transocean Well Control Manual which will be used for this drilling campaign.

The Jansz-Io Drilling Programme which is the primary communication tool for involved staff and contractors and contains a summary of the safety features (e.g. casing, mud and logging programmes, casing, and leak off pressure testing, and well control). A copy of this document will also be located on the DWF.

Use of a drill rig and generic drilling programme with previous proven success elsewhere.

Use of personnel with local area experience.

Compliance with the APPEA Code of Environmental Practice.

All ExxonMobil and contractor personnel will undertake an induction prior to the commencement of the drilling programme. This induction will address the issues and actions identified within this EP.

Table 8-1 summarises the management actions that ExxonMobil and its drilling contractor will undertake to ensure protection of the environment and should be used with the more detailed performance objectives, standards and criteria.

Table 8-1 Summary of Management Actions

Topic Management Action

Physical presence (disturbance to marine fauna and benthic habitat)

• Location and scheduling of drilling programme to avoid peak humpback migratory periods and pathways.

• Use of a dynamically positioned drill rig to avoid anchoring impacts.

Drill muds • WBM to be used for the upper hole systems, low toxicity NADF to be used for lower hole section.

• Minimise volume disposed by: retention of base drilling mud for the duration of the well; optimisation of the solids control equipment; application of sound drilling mud engineering practices; and good supervision and communication.

• Recover bulk NADF for reuse.

Drill cuttings • Discharge to sea in accordance with normal operating procedures (after drilling mud recovery over shale shakers during NADF usage). NADF ROC<10% by dry weight per Section 6.3.1.

Deck wash-down waste • Ensure absorbents and containers are available on the drill rig to clean up small accumulations of oil and grease around work areas and decks.

• Ensure accumulations of oil, grease and other contaminants are collected and removed from the decks prior to any wash-down. Wash-down drainage will be directed to a settling tank to separate any oil from water prior to discharge of the water. Uncontaminated deck water may be discharged directly overboard.

• Routinely wash down upper deck using biodegradable detergents.

Sewage and putrescible wastes • Discharge sewage and putrescible wastes via direct overboard drain after being macerated and pulverised in accordance with OPGGSA regulations, and MARPOL regulations (service vessels).

• Ensure proper operation of on-board sewerage treatment plant.

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development


Solid wastes • Store all solid wastes on board the drill rig, in appropriate containers, for transport ashore where they will be disposed of in full accordance with local and State regulations.

Hazardous wastes • Store all hazardous wastes on board the drill rig, in appropriate containers, for transport ashore where they will be disposed of in full accordance with local and State regulations.

Ballast water • Ballasting operations to be undertaken in accordance with AQIS Guidelines.

Bilge water • Bilge water discharge to be in accordance with all relevant legislation and procedures.

Interference with commercial fisheries • AMSA to be notified of drill rig location and timing of drilling.

Interference with shipping • AMSA to be notified of drill rig location and timing of drilling.

Interference with recreational fisheries • AMSA to be notified of drill rig location and timing of drilling.

Refuelling / transfers • Re-fuel will be undertaken during hours of daylight except in emergency situations.

• Use transfer hoses with ‘dry break’ couplings.

• Ensure refuelling operations are continuously overseen by the drill rig OIM (or designated replacement).

• Ensure that all refuelling activities are undertaken in accordance with ExxonMobil accepted procedures.

• Develop and test the OSCP.

• Record and report all spills to ExxonMobil and > 80 L to DMP.

Vessel Collision • Ensure that AMSA is notified in advance of rig movement.

• Establish safety zone around drill rig (Section 329 of OPGGSA 2006).

• Record all incidents.

The loss of well control and blow-out • Test the BOP prior to commencement of operations and regularly during operations.

• Pressure test casing strings.

• Continuously monitor for abnormal pressure parameters during drilling.

• Ensure the drill crew is fully trained in emergency well control and OSCP procedures.

Spillage of crude oil during well testing • Direct the early flow to tanks while there is a possibility of drilling mud’s contaminating the hydrocarbon and extinguishing the flame.

• Evergreen burner used to match the expected gas type.

• Ensure that all well testing activities are undertaken in accordance with ExxonMobil accepted procedures.

Spillage of hydraulic fluids • Ensure that equipment maintained and that drip pans and bunds are in place.

• Record and report all spills to ExxonMobil and > 80 L to DMP.

Atmospheric emissions • Ensure that all equipment is well maintained and engines are tuned to minimise emissions.

• Record all fuel gas usage and gas to flare.

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development


Well test discharges • Ensure that ExxonMobil well testing procedures and sand filter cleaning procedures are followed.

Tank Cleaning Ensure tank discharges are diluted through the cleaning process (seawater and surfactants).

Evaluate samples to determine suitability for discharge (further dilution conducted to ensure less than 10% residual NADF).

Interface Fluids Management of displacements by containing NADF interfaces on surface, testing oil content and treating as required.

Ensure interfacial fluid(s) are treated to an acceptable level prior to discharge.

8.2 Third Party Contractor Management

The main ExxonMobil third party contractors involved in the Jansz-Io Drilling campaign, along with any associated equipment, are shown in Table 8-2. Where contractors are providing services or equipment which is deemed to be Operations Integrity Management System (OIMS) [Ref Section 4.2] critical (i.e. critical in ensuring safety and integrity), the contractors’ HSE Management Systems are reviewed as part of the contractor selection process to ensure they incorporate appropriate systems to manage safety and integrity.

Approval and management of contractors working on the Transocean DWF will occur via the Transocean Vendor Evaluation and Approval Procedure and the Transocean Contractor Oversight Procedure [Ref 53]. All third party contractors must work under the Transocean HSE Management System (HSEMS) and under the control of the OIM.

The safety of equipment supplied by service contractors is controlled through the Transocean policy regarding authorisation to rig-up third party equipment. A Third Party Equipment Installation Checklist is used which includes a list of typical precautions and checks that may be needed. This control mechanism ensures that all necessary data and information for the 3rd party equipment are supplied to Transocean and are available on the DWF.

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

Table 8-2 Third Party Contractors and Equipment Inventory for Jansz-Io

Supplier Purpose / Equipment

Weatherford Casing Running

Schlumberger Cement Services and Accessories / Wireline logging/ subsea test tree

MI SWACO Drilling Fluids

Weatherford Drilling Tools

Baker Hughes MWD/LWD/Directional Services

Weatherford Fishing Tools

Bristow Helicopters

Baker Hughes Mud Logging

Fugro Rig Positioning

Oceaneering ROV Services

Maersk and P&O Supply Vessels

GE Oil & Gas Wellhead Services

Expro Well Test

8.3 Roles and Responsibilities

It is the intention of Transocean and ExxonMobil to have a clear demarcation of HSE interfaces to ensure there will be no confusion between the roles and responsibilities of personnel, organisations, management of safety, operating procedures and/or reporting structure.

Transocean as the ‘Facility Operator’ under the OPGGSA, has ultimate responsibility for HSE on the Deepwater Frontier and ExxonMobil will comply with all Transocean/ Deepwater Frontier HSE policies and procedures. The Transocean DWF is under the day-to-day management and control of the Transocean appointed Vessel Master. The Transocean DWF Vessel Master along with the onshore Transocean DWF Rig Manager, is accountable and responsible for cascading the requirements of the Company Management System (CMS) to employees and contractors, and for implementing the CMS throughout Transocean operations. Transocean will also implement the environmental control measures described in this EP.

Where potential or unexpected gaps or conflicts in procedures arises during the course of operations, the Transocean policy will apply and may be subject to risk assessment of the specific task in question at the time. Should ExxonMobil and Transocean not agree on the resolution of any conflict onboard, the specific task or operation will cease until an agreement is reached and documented on the safest way to proceed.

The interfaces between the Transocean and ExxonMobil organisations including contractors are illustrated in Figure 8-1. An organisation chart for the campaign is provided in Figure 8-2 and roles and responsibilities for key personnel are outlined in Table 8-3.

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

Figure 8-1 Transocean-ExxonMobil/Contractor Interface

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

Figure 8-2 Organisational Chart

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

Table 8-3 Roles and Responsibilities

Role Location Responsibilities

ExxonMobil Drilling Manager

Onshore Ensures compliance with ExxonMobil Environment Policy.

Ensures overall compliance with this EP with advice and guidance from ExxonMobil drilling engineers, Transocean rig OIM and ExxonMobil Regulatory and Environment Lead.

Assumes responsibility for providing adequate resources for environmental management.

EMDC Drilling Operations Superintendent

Onshore Ensures compliance to relevant environmental legislative requirements, commitments, conditions and procedures as provided in this EP.

Reports to regulatory authorities as appropriate.

Reports environmental incidents to the ExxonMobil Field Drilling Manager and ensures follow-up actions are carried out.

Assists ExxonMobil Field Drilling Manager and ExxonMobil Drilling Supervisor in the event of an environmental incident.

Ensures corrective actions from environmental audits are closed out in a timely manner.

Transocean Offshore Installation Manager (OIM)

Offshore Implements and ensures compliance to relevant environmental legislative requirements, commitments, conditions and procedures as detailed in this EP.

Communicates environmental hazards and risks to the rig workforce and the commitments of this EP.

Implements corrective actions from environmental audits in a timely manner.

EMDC Drilling Operations Supervisor

Offshore Monitors that the relevant environmental legislative requirements, commitments, conditions and procedures as detailed in this EP are being followed on the drill rig and support vessels.

Maintains clear communication between ExxonMobil and Transocean on environmental issues.

Reports environmental incidents and ensures follow-up actions are taken.

ExxonMobil Regulatory and Environment Lead

Onshore Maintains communication with government agencies and the media (via ExxonMobil Public Affairs).

Carries out environmental education and inductions on the rig.

Coordinates environmental audits of the drill rig to ensure compliance.

Support Vessel Master(s)

Offshore Implements and ensures adherence to relevant environmental legislative requirements, commitments, conditions and procedures on-board the vessel.

Maintains clear communication with the crew.

Communicates environmental hazards and risks to the workforce and the importance or following good work practices.

Maintains vessel in a state of preparedness for emergency response.

Reports environmental incidents to the OIM and ensures follow-up actions are carried out.

Rig and vessel personnel and contractors

Offshore Perform work in accordance to this EP.

Attend EP training.

Follow good housekeeping procedures and work practices.

Report incidents to the OIM or the Drilling Supervisor.

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

8.4 Training, Communications and Awareness

The process of raising awareness of environmental commitments and performance requirements was initiated with the involvement of ExxonMobil personnel and Transocean personnel in the workshops and their involvement in the development and review of this EP.

All personnel, including third party contractors, involved in the campaign will undergo environmental awareness training prior to commencing work on the project as part of their induction. The environmental training will inform the work crews of their obligations and project-specific environmental management procedures, including responsibilities and lines of communication. Inductions will also cover the relevant components of this EP, ExxonMobil OIMS, Transocean HSE MS, and bridging documents developed to link the DWF and ExxonMobil procedures, roles and responsibilities.

The induction will cover aspects such as:

Environmental regulatory requirements of the project.

Marine user interaction:

- Requirement to comply with the proximity distance as per the 2005 Australia National Guideline for Whales and Dolphin Watching.

- Requirement to record and report sightings of whales and dolphins.

- Complaint/issue handling from fisheries.

Waste segregation, containment and disposal:

- No waste overboard policy.

- Requirements for waste minimisation, segregation, labelling, handling and storage.

- Requirements for recording waste movements and transfers in Garbage Record Book.

Housekeeping and spill prevention:

- Requirements to store chemicals, oils and wastes in designated area.

- Requirements to adhere to bunkering procedure for fuel transfers.

- Availability of spill transfer equipment.

Spill preparedness and response:

- Alerting procedure and immediate spill response actions.

Environmental incident reporting:

- Requirements for reporting reportable and recordable incidents. Environmental risks will be discussed through job safety analyses, pre-tour and safety meetings conducted on board the DWF throughout the Campaign.

Additional communications, including the findings of any incident investigations, will continue through daily meetings on board the DWF. Familiarity with emergency response plans will be developed through drills and an emergency response exercise.

8.5 Performance Measurement and Reporting

8.5.1 Monitoring and Stewardship

Campaign specific monitoring will include:

Review of environmental incidents.

MODU operational performance against performance measures.

Mass balance calculations on use of drilling fluids.

The discharge of domestic wastes from the DWF and supply vessels will be periodically monitored to ensure that the performance standards in place for the activity are met. All solid and hazardous wastes stored on-board vessels and the DWF and sent onshore for disposal will be recorded in a waste manifest. Volumes of fuel used during drilling will also be recorded on daily logs.

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

All environmental incidents or deviations from this EP are to be reported in accordance with ExxonMobil’s Incident Reporting and Investigations Procedure (ExxonMobil OIMS (SMS) Manual). In addition, all incidents arising out of operations for the activity that are not within the parameters of the environmental performance standards in this EP will be reported, in line with Regulation 26 of the Offshore Petroleum and Greenhouse Gas Storage (Environment) Regulations 2009.

Table 8-4 provides a summary of the environmental risk monitoring requirements for the project-related activities. This should be considered along with the Performance Standards, Objectives and Criteria in Section 7. The OIM and ExxonMobil Drilling Supervisor are responsible for ensuring the monitoring is undertaken as per this EP.

Table 8-4 Summary ExxonMobil environmental monitoring/recording requirements

Environmental Risk Criteria to be Monitored Frequency of Monitoring

Hazardous waste disposal Type and volume Ongoing

Diesel usage Volume Ongoing

Oil spills Type and volume Ongoing

Chemical spills Type and volume Ongoing

NADF cuttings discharge Volume of cuttings and ROC Daily During Drilling

Fuel use: rig, service vessels Volume Weekly

Flare volume Volume Weekly

Vessels entering safety zone Per incident Ongoing

Oily water discharge volume Continuous during discharge Ongoing/as necessary

Waste to shore from rig Volume and type Event/consignment

Domestic waste discharge Discharge volumes; Compliance with MARPOL 73/78

Ongoing

Sightings and Impacts to wildlife Wildlife Type Ongoing

8.5.2 Routine Reporting

For the duration of the drilling campaign, daily reports outlining routine drilling activities, volumes of cuttings discharged, environmental incidents, and diesel consumed and so on will be collected by ExxonMobil and forwarded to the DMP.

ExxonMobil will submit to the DMP, not later than the 15th of the subsequent month, a dedicated monthly campaign report providing a summary of the routine reports and other appropriate information as per Offshore Petroleum and Greenhouse Gas Storage (Environment) Regulations, 2009 (Cth) r. 26B. This includes:

A record of all recordable incidents that occurred during the calendar month.

All material facts and circumstances concerning the recordable incidents that the ExxonMobil knows or is able, by reasonable search or enquiry, to find out.

Any action taken to avoid or mitigate any adverse environment impacts of the recordable incidents.

The corrective action that has been taken, or is proposed to be taken, to prevent similar recordable incidents.

Reporting of MODU operations to the DMP will be part of an end of campaign close out report submitted to the DMP. This report will include the following operational performance data as a minimum:

Volume of cuttings overboard (m3).

Volume of NADF used (bbl).

Volume of WBM used (bbl).

Volume of other muds used (bbl).

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

ROC average%.

Prescribed industrial wastes to shore (m3).

Bilge water overboard.

General waste to shore (m3).

Putrescible wastes (food-scraps) overboard (m3).

Sewage overboard.

Waste incinerated (m3).

Emissions to air from flaring, venting and/or reinjected (km3).

Diesel usage (KL).

8.5.3 Reporting of Incidents

All incidents and near misses will be reported by Transocean to ExxonMobil.

ExxonMobil will notify and report incidents to the DMP in accordance with r. 26 of the Offshore Petroleum and Greenhouse Gas Storage (Environment) Regulations, 2009 (Cth), under which:

The operator (ExxonMobil) of an activity must give notice, verbally or in writing, of a reportable incident to the Designated Authority (DMP), including all material details of the incident that are reasonably available to the operator as soon as practicable, but within 2 hours after:

a) the first occurrence of the incident; or

b) if the reportable incident was not detected by the Operator at the time of the first occurrence – the time the Operator becomes aware of the reportable incident.

DMP reportable incidents are shown below.

DMP

Duty Officer: 0419 960 621

1) verbally within 2 hrs of incident, then

2) written report within 3 days

An unplanned event that has been assessed through the risk assessment process (Section 5.1) to have a consequence ranking of I or II.

80 litres or more of hydrocarbon or hazardous chemical discharged to sea.

An unplanned gaseous release to atmosphere of 500m3 or more.

Injury or mortality to individual(s) of an EPBC Act Listed Fauna.

Unplanned impact caused to a matter of national environmental significance.

Following the initial notification, ExxonMobil will provide written reports on any reportable incidents to DMP within three days of the first occurrence of the reportable incident and will maintain a record of each report and details of any corrective action taken. Under r. 26A(4)(c), both the initial notification and written report will cover, as a minimum:

all material facts and circumstances concerning the recordable incident that the operator knows of, or is able, by reasonable search or enquiry, to find out;

any action taken to avoid or mitigate any adverse environmental impacts of the recordable incidents; and

the corrective action that has been taken, or is proposed to be taken, to prevent a similar recordable incident.

A “recordable incident”, i.e. any incident that breaches a performance objective of this EP (refer Section 5.1) and is not a “reportable incident”, will be reported to the DMP within the monthly report described above.

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

SEWPAC reportable Incidents are shown below:

SEWPAC

[email protected]

within 24 hrs of detection

Injury or mortality to EPBC Act Listed Fauna

In addition to the above reporting requirements, the following items must also be reported:

Incident Report to

All oil pollution incidents (any quantity) in Commonwealth waters are to be reported to AMSA under Marine Notice 1/1996;

AMSA within 24 hrs

24 Hour Emergency Contact Numbers

1800 641 792 (Maritime)

1800 815 257 (Aviation)

or

+612 6230 6811 (Maritime)

+612 6230 6899 (Aviation)

Any spills greater than 10 tonnes in Commonwealth waters are to be reported to AMSA within one hour.

AMSA within 1 hr

24 Hour Emergency Contact Numbers

1800 641 792 (Maritime)

1800 815 257 (Aviation)

or

+612 6230 6811 (Maritime)

+612 6230 6899 (Aviation)

Any spills over 80 litres will be reported to the National Offshore Petroleum Safety Authority (NOPSA). Compliance with the National Offshore Petroleum Authority Guidelines on the Notification and Reporting of Accidents and Dangerous occurrences will also be adhered to.

NOPSA within 2 hrs

Incident Notification Telephone Number

(08) 6461 7090

In accordance with requirements ExxonMobil will report the following pollution incidents:

Any quantity of oil discharged (oil includes waste oil, fuel oil, sludge, lube oil and additives etc).

Any discharge from a ship involving washings of chemical or dry cargoes.

Any discharge of plastic material.

Garbage disposed of in the sea within 12nm of land (garbage includes food, paper, bottles etc).

8.5.4 Incident Investigation

Investigations into environmental spills or loss of control will be conducted in accordance with ExxonMobil incident investigation procedures and guidelines set by Regulations. Investigation teams may include Transocean representative(s) as agreed in consultation with the Transocean Rig Manager and the ExxonMobil Operations Superintendent; the team leader for investigations will be either an ExxonMobil investigator or ExxonMobil appointed objective third party. These will be reported using the ExxonMobil reporting format.

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

8.5.5 Management of Change

Changes to the DFW, Transocean CMS and/ or operating procedures including those requested by ExxonMobil shall be managed in accordance with the Transocean CMS [Ref 53]. In assessing changes to the planned campaign ExxonMobil applies a Management of Change (MoC) process. This process applies risk assessment to the MoC to ensure the risks associated with any proposed changes are kept to ALARP.

Any changes to the drilling programme will be updated in the Standing Instructions to Drillers which will then be endorsed by the DFW Vessel Master. Transocean and ExxonMobil agree to consult whenever a change may impact on safety or operations on the DFW.

8.5.6 Auditing and Management Review

ExxonMobil will undertake internal audits of compliance against this EP. One overall EP audit will be conducted during the Campaign along with one pre-use NADF audit and one NADF Audit that will be conducted within one week of the DWF using NADF.

ExxonMobil intend to conduct as a minimum one full environment audit annually. This will be supplemented with at least one annual audit during the use of NADF.

Compliance auditing against the EP will be included in the annual report submitted to the DMP.

8.5.7 Assessments

ExxonMobil will undertake environmental compliance assessments to ensure that the environmental performance objectives outlined within this EP have been met. Assessments may include:

Compliance with regulatory requirements and this EP.

Management of environmental incidents or issues, e.g. fuel spills, unauthorised waste discharges etc.

Logs of environmental matters which may have future significance (e.g. volumes and types of discharges, waste disposal manifests and facilities used, etc.).

The results of these assessments will be made available to DMP on request.

8.6 Consultation

Consultation with stakeholders has been undertaken by Chevron Australia as the Gorgon Operator on a regular basis throughout the development of the environmental impact assessment, management documentation for the Gorgon Gas Development and the Jansz Feed Gas Pipeline. This has included engagement with the community, government departments, industry operators and contractors to Chevron Australia via planning workshops, risk assessments, meetings, teleconferences and the PER EIS/ERMP formal approval processes.

Consultation specific to this Jansz-Io drilling activity has been undertaken by ExxonMobil with the following relevant authorities and stakeholders:

Western Australian Department of Industry and Resources (DMP).

Commonwealth Department of Sustainability, Environment, Water, Population and Communities (SEWPAC).

National Offshore Petroleum Safety Authority (NOPSA).

Australian Maritime Safety Authority (AMSA).

Australian Marine Oil Spill Centre (AMOSC).

Western Australian Fishing Industry Council.

Western Australian Department of Fisheries.

Australian Fisheries Management Authority.

Commonwealth Fisheries Association.

The main outcomes of the consultation process were the following:

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

There are no major fishing activities expected from the State or Commonwealth fisheries in the Jansz-Io region.

The Jansz-Io drilling activities are not expected to impact on any known recreational fishing grounds.

The Jansz-Io drilling activities will not be occurring in a major commercial shipping route.

In addition, ExxonMobil will advise AMSA and the Department of Defence in advance of the activity to allow appropriate communication and notification to other stakeholders who may utilise the area.

8.7 Emergency Preparedness and Response

8.7.1 Emergency Response Responsibilities

Responsibilities for the purposes of emergency response are outlined as follows:

Transocean Ltd is the “Operator” of the Facility and has legislative responsibilities for all operations on the DWF MODU, including response to emergencies.

ExxonMobil’s role in dealing with emergencies is to provide the necessary resources to support a Transocean emergency response. ExxonMobil’s drilling team will operate from the company’s Melbourne and Perth office. Additional management, technical and emergency response support will be provided from the Melbourne and Houston offices.

ExxonMobil is supported by Chevron Australia’s (CVX) emergency management systems and resources.

8.7.2 Emergency Response Documentation

In the event of any emergency on the Transocean DWF, the DWF Emergency Procedures Manual (EPM) is the primary document that details how emergencies will be managed.

The Jansz-Io Bridging Emergency Response Plan (ERP) [Ref 31] has been developed to support the existing DWF EPM. It defines the location specific arrangements for responding to emergencies including the role of helicopter and vessel support functions, cyclone evacuation planning, medivac, regulatory liaison and reporting.

The Bridging ERP addresses local responses for ExxonMobil Western Australian operations including appropriate support linkages to ExxonMobil's Australian and corporate-wide Emergency Preparedness and Response network including in-country, regional and global Emergency Support Groups. The Bridging ERP also details how Transocean, ExxonMobil and Chevron Australia will interact in the event of an emergency. A campaign specific Jansz-Io Contacts Directory [Ref 31] listing all contact numbers has also been developed.

Contractors will be required to have an up-to-date Emergency Response Manual (ERM) and a Shipboard oil spill contingency plan that includes site-specific detailed response and investigative arrangements.

Both Transocean and ExxonMobil emergency response plans and associated capabilities have been tested on previous campaigns. Independently facilitated Emergency Response Desktop exercises will be held periodically to test interfaces and response strategies. Findings and recommendations from these exercises will be incorporated into the Bridging ERP.

8.7.3 Oil Spill Contingency Plan (OSCP) and Resources

ExxonMobil has produced a project OSCP that includes resources to manage a Tier I oil spill and arrangements for handling larger spills [Ref 30]. Equipment can be sourced locally through mutual aid contacts (MAC) and through the Australian Marine Oil Spill Centre. ExxonMobil, as a member of AMOSC, has priority access to spill response equipment and training. The OSCP lists oil spill equipment available for responding to an oil spill.

8.7.4 Cyclones

The Jansz-Io campaign will run through the annual cyclone season of the North West Coast of Australia. In the event of a cyclone occurring in the region, emergency response cyclone procedures shall be

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

followed, as per the Jansz-Io Bridging Emergency Response Plan and Transocean Emergency Response Manual [Ref 31 and 54].

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

9 REFERENCES

1. Allen, G. 1997, Marine Fishes of Tropical Australia and South-East Asia, Third revised edition, Western Australian Museum, Perth.

2. AMSA 1997. Australian Offshore Support Vessel Code of Safe Working Practice, Australian Maritime Safety Authority, 1997

3. ANZECC, 1998. Interim Ocean Disposal Guidelines. Australian and New Zealand Environment and Conservation Council, December 1998.

4. ANZECC/ARMCANZ, 2000. Australian and New Zealand water quality guidelines for fresh and marine waters. October. Prepared by Australian and New Zealand Environment and Conservation Council and Agricultural and Resource Management Council of Australia and New Zealand.

5. APASA, 2002. Quantitative Assessment of Exposure Risk From Hypothetical Oil Spills From The Proposed Jansz-2 and Jansz-3 Appraisal Wells. Permit Area WA-268-P. Report prepared for MEPC, August 2002.

6. APASA, 2011. J0107 - ExxonMobil Jansz Io Hydrocarbon Risk Assessment

7. APPEA 2005. A compilation of recent research into the marine environment. Australian Petroleum Production and Exploration Association, 2005.

8. APPEA, 2008. Code of Environmental Practice. Prepared by Australian Petroleum Production and Exploration Association Limited.

9. AQIS, 2001. Australian Ballast Water Management Requirements. Prepared by the Australian Quarantine and Inspection Service.

10. ASA, 2011. Impact of Deepwater Blowouts in the Gulf of Mexico on Oil Mass Balance and Associated Spill Response. Applied Science Associates, February 2011,

11. Ashley D. M. Coutts; Richard F. Piola; Chad L. Hewitt; Sean D. Connell; Jonathan P. A. Gardner Effect of vessel voyage speed on survival of biofouling organisms: implications for translocation of non-indigenous marine species, The Journal of Bioadhesion and Biofilm Research, 2009

12. Australian Fisheries Management Authority, The Commercial Fishing Industry, retrieved 22/11/2007 at http://www.afma.gov.au/fisheries/industry/default.htm.

13. BHP Billiton (2006) – Environmental Impacts and Management Measures: Pyreness Development, A www publication accessed on http://www.bhpbilliton.com/ bbContentRepository/docs/OurBusiness/Petroleum/06EnvironmentalImpactsandManagementMeasures.pdf in February 2007

14. BOM, 2007, Climate Averages downloaded 23rd Nov, 2007, at http://www.bom.gov.au/climate/ averages/tables/cw_098017.shtml.

15. Bowman Bishaw Gorham, (2000). Environment Plan Jansz-1 Exploration Well WA-268-P. Report prepared for Mobil Exploration and Producing Australia, March 2000.

16. Cailliet, G.M., Cavanagh, R.D., Kulka, D.W., Stevens, J.D., Soldo, A., Clo, S., Macias, D., Baum, J., Kohin, S., Duarte, A., Holtzhausen, J.A., Acuña, E., Amorim, A. & Domingo, A. 2004. Isurus oxyrinchus. In: IUCN 2010. IUCN Red List of Threatened Species. Version 2010.4.

17. Caroline R Weir 2007. Observations of Marine Turtles in Relation to Seismic Aurgun Sound off Angola Marine, Ketos Ecology, 2007.

18. Clarke, E., 1992, Whale Sharks, in National Geographic, December, pp123, 126-131, 134-138.

19. Cogger, H.G., 1975, Sea Snakes of Australia and New Guinea, In: The Biology of Sea Snakes, Dunson, W.A., (Ed), University Park Press, Baltimore.

20. Department of Environment and Conservation, 2007, Management Plan for the Montebello/Barrow Islands Marine Conservation Reserves, 2007-2017, Management Plan No 55, Downloaded on 19th November, 2007, at http://www.naturebase.net/component/option, com_hotproperty/task,view/id,117/Itemid,755/.

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

21. Department of Industry and Resources (DoIR) (2007b) – Guideline on Minimising Acoustic Disturbance to Marine Fauna. A www publication accessed on http://www.doir.wa.gov.au/ documents/mineralsandpetroleum/ED_Pet_GL_MinAcousticDisturbanceMarineFauna_Jan07.pdf in May 2007

22. Department of Sustainability, Environment, Water, Population and Communities (2011). Megaptera novaeangliae in Species Profile and Threats Database, Department of Sustainability, Environment, Water, Population and Communities, Canberra.

23. Department of Sustainability, Environment, Water, Population and Communities (2011). Balaenoptera musculus in Species Profile and Threats Database, Department of Sustainability, Environment, Water, Population and Communities, Canberra.

24. DEWHA, 2007. EPBC Act Policy Statement 2.1 – Interaction between offshore seismic exploration and whales. Prepared by Department of Environment and Water Resources.

25. DEWHA, 2009 Guidelines for the Preparation and Submission of an Environment Plan

26. DEWHA, 2005. Australian National Guidelines for Whale and Dolphin Watching. Department of Environment, Water, Heritage and the Arts, 2005.

27. DoIR 1998. Drilling Fluids Management. Prepared by the Western Australian Department of Industry and Resources, Perth, Western Australia.

28. EPA. 2000. Environment Protection (Ozone Protection) Policy 2000. Environment Protection Authority.

29. ExxonMobil Operations Integrity Management System (OIMS)

30. ExxonMobil Development Company, Jansz-Io Drilling Project Oil Spill Contingency Plan (AUJZ-EDD-07-DR-511-R01-0070)

31. ExxonMobil Development Company, Jansz-Io Drilling Emergency Response Bridging Document (AUJZ-EDD-07-DR-511-R01-0072)

32. Jansz-Io Work Operator Interface and Transition Plan 2010. Doc AUJZ-EDD-07-DR-511-R01-0066

33. Jansz-Io Unitisation and Unit Operating Agreement, 2009. Parties of the Unit Operating Agreement Doc. DMS 091540028

34. Heatwole, H., and Seymour, R., 1975, Diving Physiology, In: The Biology of Sea Snakes, Dunson, W.A., (Ed), University Park Press, Baltimore.

35. Heatwole, H., 1987, Sea Snakes, New South Wales University Press, Kensington, NSW, Australia.

36. Heyward, A.J., Revill, A.J., and Sherwood, C.R., 2000, Review of Research and Data Relevant to Marine Environmental Management of Australia’s North West Shelf, Western Australian Department of Environmental Protection, January.

37. Hinwood, J. B., Potts A.E., Dennis, L. R., Carey, J. M., Houridis, H., Bell, R. J., Thompson, J. R., Boudreau, P. and Ayling, D.M., 1994. Environmental Implications of Offshore Oil and Gas Development in Australia – Drilling Activities. In Swan, J. M., Neff, J. M. and Young, P. C. (eds). Environmental Implications of Offshore Oil and Gas Development in Australia – The Findings of an Independent Scientific Review. Australian Petroleum Exploration Association (APEA) and Energy Research and Development Corporation (ERDC). Sydney.

38. IRCE (2006) Jansz-lo Deepwater Gas Development Environmental Plan, Report prepared for Mobil Exploration and Producing Australia Pty Ltd by IRC Environment.

39. IRCE, (2005). Jansz Pipeline Benthic Fauna Survey, Unpublished report prepared for Mobil Exploration and Producing Australia Pty Ltd by IRC Environment, ENV-REP-04-228-003 Rev B, Perth, Western Australia.

40. Jenner, K. C. S., Jenner, M-N. M, and McCabe, K. A., (2001). Geographical and Temporal Movements of Humpback Whale in Western Australian Waters, APPEA Journal 2001, pp.749-765.

41. Kailola, P. J., Williams, M.J., Stewart, P.C., Reichelt, R.E., McNee, A., Grieve, C., 1993. Australian Fisheries Resources Bureau of Resource Sciences, Department of Industries and Energy, and the Fisheries Research and Development Corporation. Canberra.

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

42. Last, P.R. and Stevens, J.D., 1994, Sharks and rays of Australia, CSIRO, Australia.

43. MARPOL, 2007. MARPOL ANNEX IV – Regulations for the prevention of Pollution by Sewage from Ships. Revised regulations.

44. McCauley, R. (1998). Radiated Underwater Noise Measured from the Drilling Rig Ocean General, Rig Tenders Pacific Ariki and Pacific Frontier, Fishing Vessel Reef Venture and Natural Sources in the Timor Sea, Northern Australia, report prepared for Shell Australia, Melbourne, July 1998.

45. Metocean Criteria for Drilling at Jansz (Letter Report dated 31 January 2011)

46. National Centre for Environment Predictions (NCEP)

47. OSPAR 2004. Report on Discharges, Spills and Emissions from Offshore Oil and Gas Installations, OSPAR Commission, 2004

48. Pendoley, K.L., 2005, Sea Turtles and the Environmental Management of Industrial Activities in North Western Australia, Thesis, for degree for Doctor of Philosophy, Murdoch University.

49. Rainer, S.F., 1990. High species diversity in demersal polychaetes of the North West Shelf of Australia.

50. SCOMI 2010, Environmental Survey Deepwater Frontier, Scomi Oilfield Services, November 2010

51. SEWPAC, 2011 Environment Protection and Conservation Act Protected Matters Report, Coordinates, Department of Sustainability, Environment, Water, Population and Communities (2011)

52. Swan, J.M., Neff, J.M. and Young, P.C. (Eds.), 1994. Environmental Implications of Offshore Oil and Gas Development in Australia, The Findings of an Independent Scientific Review. Australian Petroleum Exploration Association (APEA), Energy Research and Development Corporation (ERDC), Australia.

53. Transocean Deep Water Frontier Safety Case Revision

54. Transocean Emergency Response Manual

55. Ward, T.J. and Rainer, S.F., 1988. Decapod crustaceans of the North West Shelf, a tropical continental shelf of North-western Australia. Australian Journal of Marine and Freshwater Research 39: 751-765. Cited in: Bridgewater, P., 1990. Ningaloo Marine Park (Commonwealth Waters). Plan of management. Australian National Parks and Wildlife Service.

56. Wild Well Control Inc., 2011. Esso Australia Pty Ltd-Jansz, Operational Dynamic Kill Plan, Wild Well Control Inc, 2011.

57. Woodside, 1988. Physical, chemical and biological characteristics of the Goodwyn Field. Woodside Offshore Petroleum Pty Ltd. September 1988.

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

Appendix 1 Environmental Risk Register

G1-NT-PLNX0001089

JANSZ-IO DRILL PROGRAMME

TRANSOCEAN DEEPWATER FRONTIER ENVIRONMENTAL HAZID and RISK ASESSMENT

Document No: AUJZ-EDD-07-DR-511-R01-0073 Revision: 0

Revision Date: June 2011

Development

G1-NT-PLNX0001089

JANSZ DRILLING PROJECT

ENVIRONMENTAL HAZID AND RISK ASSESSMENT

AUJZ-EDD-07-DR-511-R01-0073 Jansz HAZIDAssessment Rev 0 Page 2 of 16

Development

Revision History

Revision Date Description Prepared by

Checked by

Approved by

A Issued for Review B. Lucas 0 June, 2011 Issued R. Lal

G1-NT-PLNX0001089




Development

Table of contents 1. SUMMARY ............................................................................................................................... 4

2. INTRODUCTION ...................................................................................................................... 5

3. HAZARD WORKSHOP ............................................................................................................ 6

3.1 Objectives and Scope 6

3.2 HAZID and Risk Assessment Attendees 6

3.2 Methodology 6

4. RESULTS ................................................................................................................................. 7

5. REFERENCES ......................................................................................................................... 8

6. Abbreviations ........................................................................................................................... 9

Appendices

Appendix 1 Workshop Minutes

Appendix 2 Workshop Attendees

Appendix 3 Hazard Charter

G1-NT-PLNX0001089




Development

1. SUMMARY

This technical note documents the Environmental HAZID Assessment that was carried out on the Jansz-lo drilling programme, which is located within the WA-18-R permit area of the North West Shelf of Australia.

The HAZID was conducted as a facilitated workshop and was held on the 28th April 2011. Project personnel from Transocean, Exxon Mobil Drilling operations and engineering, and third party contractors attended the workshop.

The results of the HAZID were recorded and a copy of the completed register is provided in Appendix 1. The focus of the review was to determine the environmental risks associated with Jansz-Lo campaign, in order that controls can be identified, and the risk to the environment minimised to As Low As Reasonably Practicable (ALARP). This report provides information for the Environmental Plan for the campaign, as required by the Offshore Petroleum and Greenhouse Gas Storage (Environment) Regulations 2009.

Where an environmental risk was identified, then this was qualitatively assessed by the workshop team using the Exxon-Mobil risk matrix.

There were 28 environmental risks identified, no higher risks were identified, and 10 were classified as medium and 18 as low. There were 16 actions identified associated with assurance that campaign risks are managed to ALARP. A full listing of the hazards, risks, and actions are included in Appendix 1.

G1-NT-PLNX0001089




Development

2. INTRODUCTION

Exxon-Mobil has contracted the Transocean Deepwater Frontier (DWF) to conduct drilling and intervention activities in the WA-18-R permit area of the North West Shelf of Australia. Exxon-Mobil will manage the drilling campaign, and Transocean is the designated operator of the DWF and responsible for day to day management of the rig.

The drilling programme consists of the drilling, completion and temporary suspension of 10 subsea wells located in 2 clusters (Drill Centre 1 and Drill Centre -2) approximately 10 km apart. The programme also includes the re-entry of an existing well, Jansz-4, which will be converted to a monitoring well. Installation of the subsea trees is to be executed by a separate vessel.

In accordance with the Offshore Petroleum and Greenhouse Gas Storage (Environment) Regulations 2009 an Environment Plan (EP) for the campaign is required. This technical note documents the workshop held to identify and assess the risks associated with the campaign and provides input to the EP.

Prior to the workshop the following activities were conducted;

Hazard Workshop Charter was distributed. The Charter provides information on the drill programme together with the objectives of the hazard workshop and activities to be covered. The Charter is provided in Appendix 1.

A list of possible hazards was developed (Appendix 2) based on a review of:

i) the Jansz-Io drill programme

ii) Previous drilling conducted by ExxonMobil in the campaign area.

G1-NT-PLNX0001089




Development

3. HAZARD WORKSHOP

3.1 Objectives and Scope

The primary focus of the workshop was to review the intended drilling campaign and the DWF Formal Safety Analysis and Facility description:

To identify any unique operations associated with the campaign; and

To evaluate any hazards and to capture risk reduction measures to mitigate the risks and to ensure that the risks are As Low As Reasonably Practicable (ALARP).

3.2 HAZID and Risk Assessment Attendees

The HAZID was held at the Exxon-Mobil Melbourne office’s on the 28th April 2011. The workshop was attended by representatives from Transocean, Exxon-Mobil and third party contractors. The workshop was facilitated by an independent third party. A list of participants is provided in Attachment 2 of this report.

3.2 Methodology

The workshop commenced with an introduction to the risk assessment process and the proposed drilling programme (refer to Attachment 3 for drilling presentation). The drilling campaign was split into the following key areas:-

MODU movements including support vessels

Support activities including helicopters, ROV, Field Vessels, personnel issues

Reservoir related issues

Drilling and completion of wells

Temporary suspension of wells

SIMOPS activities (including vessel interactions, particularly with Subsea tree installation vessel)

Jansz-4 re-entry and conversion

Shared services with Chevron (including emergency response services, support vessels, supply base)

Seasonal variations (e.g. cyclones)

During the workshop session the team brainstormed possible risks to the environment for each step in the campaign. The independent facilitator then prompted discussion by use of hazards associated with drilling activities that had been identified in similar drilling campaigns.

The team then reviewed all hazards documented and assessed whether:

The hazard recorded fully reflected the intended drilling activity and in place controls;

The risk of each hazard eventuating was then assessed using the Exxon-Mobil risk matrix; and

Any additional controls considered necessary to minimise risk were recorded.

Actions were raised where further work or mitigation measures were required. Full minutes are provided in Appendix 1.

.

G1-NT-PLNX0001089




Development

4. RESULTS

There were 28 risks identified for the campaign, however none of the risks were assessed to be high and all risks were considered to be ALARP with the identified risk reduction measures implemented. There were 16 actions identified from the campaign that are required to be closed out prior to the commencement of drilling to ensure that the risks to the environment are ALARP. The Jansz-Io Hazard Register in Appendix 1 lists all details of the HAZID and the action items.

G1-NT-PLNX0001089




Development

5. REFERENCES

1. Transocean Deepwater Frontier HSE Case

G1-NT-PLNX0001089




Development

6. ABBREVIATIONS

Term Definition

ALARP As Low As Is Reasonably Practicable

DWF Deep Water Frontier

EP Environmental Plan

HSEMS Health Safety Environment Management System

HAZID Hazard Identification Session

HSE Health, Safety and Environment

G1-NT-PLNX0001089



AUJZ-EDD-07-DR-511-R01-0073 Jansz HAZIDAssessment Rev 0

Development

APPENDIX 1

WORKSHOP MINUTES

G1-NT-PLNX0001089




Development

APPENDIX 2

WORKSHOP ATTENDEES

G1-NT-PLNX0001089




Development

Name Company Position

Barbara Lucas Nuffield Facilitator

Rajan Lal Exxon-Mobil Safety

Ron Thomaso n Exxon Mobil Drilling interface Advisor

Michael Fiel Transocean Vessel Master

David Blain Transocean Toolpusher

Simon Walker Transocean QHSE Manager

Phil McKenzie RPS Energy Safety

Karthik Gangiredia Transocean DWF Interface Manager

Ron Scherpenzeel Bristow Commercial Manager

Steve Wilson Exxon-Mobil Drilling Superintendent

Carl McDonald Exxon-Mobil Drilling Engineer

Matt Naeher Exxon-Mobil Drilling Engineer-Supervisor

Geoff Murch Transocean DWF Rig Manager-Performance

Rafe Britton Exxon-Mobil Drilling Engineer

Sam Falkner Exxon-Mobil Drilling Supervisor

Patrick Tomkins Exxon-Mobil Drilling Fluids Advisor

Luisa Jayme Exxon-Mobil Safety/Scribe

Liliy Scourtis Exxon Mobil Safety/Environment

Dirk Piersma Exxon Mobil Marine Advisor

G1-NT-PLNX0001089




Development

APPENDIX 3

HAZARD CHARTER

G1-NT-PLNX0001089




Development

CHARTER

Introduction ExxonMobil Development Company’s (EMDC) Australia Drill Team, on behalf of the Jansz-Io Work Operator in conjunction with Transocean International (MODU owner and facility operator) is currently developing regulatory submissions required to obtain approval to drill the Phase 1 Jansz-Io Development wells. Hazard identification and risk assessments workshops will be conducted in support of the following two submissions: 1. Jansz-Io Drilling Campaign Environment Plan 2. Transocean Deepwater Frontier Safety Case Revision. Oil spill modelling will also be conducted to assess the possible hazards associated with oil spills.

Background ExxonMobil has drilled appraisal wells Jansz 1, 2, 3 and 4 and will now drill ten additional Jansz-Io development wells. These development wells are within permit area WA-18-R which is in Commonwealth waters, approximately 200 km off the north-west coast of Western Australia (Figure 2.1). Ten development wells will be drilled and completed as part of the Phase 1 development. Five wells at DC-1 and another five wells at DC-2. Also as part of the Phase 1 programme, the Jansz -4 appraisal well will be re-entered and converted to a pressure monitoring well. All wells are designed with 2-D double-build and hold directional profiles with 80º penetrations of the reservoir to provide the desired well deliverability, with reservoir targets that fall within a 2km drilling radius from the mudline location. Sand control technology will be incorporated in the well completions due to the shallow, unconsolidated nature of the reservoir and the potential for sand production. All wells will be completed as open-hole gravel packs.

Objectives The objectives of the workshop are to: i. Identify potential environmental hazards and Major Accidents Events (MAEs) associated

with the drilling activities. ii. Identify controls that will prevent and or mitigate the potential impact to reduce the

potential risk to as low as reasonably practicable. iii. Risk rank each environmental hazard / MAE based on the accepted control measures.

G1-NT-PLNX0001089




Development

Methodology The hazard workshop will be run in two parts. Part 1: Environmental hazard identification and risk assessment workshop Part 2: Safety Case Revision hazard identification and risk assessment workshop (MAE

Identification) The methodology of the workshops is:

1. Overview of the Jansz-Io wells and proposed drilling activities Part 1: Environmental Hazard Identification and Risk Assessment

2. Review the drilling activities and their possible environmental impacts. i. Agree on the appropriate risk treatment (controls) for each environmental

hazard such that the resultant environmental risk is reduced to ALARP. ii. Assign a risk ranking to each hazard using ExxonMobil Risk Assessment

matrix Part 2: Safety Case MAE Hazard Identification and Risk Assessment

3. Review the drilling activities and identify any new Major Accident Events (MAE) in addition to those listed in Transocean Risk Register/Bowtie Diagrams which may arise from the Jansz-Io, campaign specific drilling activities i. Identify controls that will mitigate new hazards or further mitigate existing hazards

such that the resultant risk is reduced to ALARP. ii. Risk rank new MAEs based on the accepted controls (Safety assessment will

use the Transocean Risk Matrix)

Scope The workshops will apply the methodology described above to each of the following activities in relation to the Jansz-Io Drilling Campaign:

MODU movements including support vessels

Support activities

Drilling and completion of Wells i. Drilling and lower completion (including geologic and mechanical sidetrack) ii. Wireline and coil tubing

Temporary Suspension of wells

SIMOPS activities (including interaction with support or installation, vessels)

Jansz-4 re-entry and conversion

Shared services with Chevron (including emergency response services, support vessels, supply base)

Seasonal variations

Boundaries The workshop will include all drilling activities included in the Jansz-Io work scope as described in the UUOA Exhibit “H” except for the following two activities which will be covered by a separate assessment :

Installation of subsea trees, Upper completions Well test activities

Resources Attendees will include representatives from Transocean, ExxonMobil Development Company and third party contractors. EMDC will arrange a facilitator and technical scribe and shall prepare the workshop report including minutes.

Deliverables A report for each workshop will be produced which includes - Minutes - Hazard Register - Action List - Attendee List

Dates The workshop is planned for the 28th and 29th April 2011 in the ExxonMobil office in Melbourne.

G1-NT-PLNX0001089




Development

Invitees Steve Wilson / Kevan Jenkins Josh Lepp / Chip Bradley Robert Spence Andy Choi/ Sam Faulkner Nils Musaeus Matt Naeher Ron Thomason Dirk Piersma Patrick Tomkins Tommy Graham Carl MacDonald Andy Taylor Rafe Britton Rajan Lal Lily Scourtis

Drilling Superintendent (EMDC) Drilling Supervisor (EMDC) Drilling Supervisor (EMDC) Drilling Supervisor (EMDC) Drilling Engineering Manager (EMDC) Drilling Engineer Supervisor (EMDC) Drilling Interface Advisor ( EMDC ) Marine Advisor (EMDC) Drilling Fluids Advisor Drilling Engineer (EMDC) Drilling Engineer (EMDC) Geoscience Project Manager (EAPL) Drilling Engineer (EMDC) Risk Engineer / Regulatory (EMDC) Environment / Regulatory (EMDC)

Julian Soles Geoff Murch Simon Walker Mike Tully TBA Karthik Gangiredla

Aus. Sector Manager (Transocean) DWF Rig Manager Performance (Transocean) Aus. QHSE Manager (Transocean) DWF Offshore Installation Manager (Transocean) DWF Toolpusher / Driller (Transocean) DWF/XOM Interface Manager (Transocean)

Barbara Lucas Luisa Jayme

Facilitator Technical Scribe

Ron Scherpenzeel Commercial Manager (Bristow)

Following Additional Participants from Third party Suppliers may attend (not considered essential) HOLD HOLD HOLD

Cementing Mud-logging ROV

Approved EMDC Drilling Engineering Supervisor: ___________________ date: _________ EMDC Drilling Operations Superintendent: ____________________ date: _________ Transocean HSE Manager: ____________________ date: _________ Transocean Rig Manager: ____________________ date: _________

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

Appendix 2 Jansz-Io Drilling Chemical List

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN

Potential Discharge Chemicals for Appendix.doc Page 1 of 4

Development

Product Name OCNS Rating Charm HQ Band Registration #

Drilling Muds

Citric Acid E 1075

Conqor 404 Ns Gold 23567

Deepclean NS Gold 24290

Deepclean/ECF 1480 E Gold 23850

Egmbe Gold 287

Glydril HC Gold 2406

Glydril LC * Note 1

Glydril MC Gold 2411

Idcap D Gold 1763

Klastop Gold 23380

Kwikseal F/M/C E 5992

Magnafloc 5250 * Note 1

Mica F/M/C E 1133

Mix Ii F/M/C E 23007

Novamod * Note 1

Novathin * Note 1

Nutplug F/M/C E 23740

Omyacal 70 E 1073

Omyacarb 10 E 1073

Omyacarb 1t E 1073

Omyacarb 20 E 1073

Omyacarb 2T E 1073

Omyacarb 40 E 1073

Omyacarb 5 E 1073

Omyacarb 8 E 1073

Pipe-Lax * Note 1

Pipelax Env Gold 24243

Polypac R E 2440

Polypac UL E 2440

Polyplus Dry * Note 1

Polyplus RD Gold 2438

Polyplus LV * Note 1

Ultracap Gold 2467

Rheflat NS D 24097

Rheochek * Note 1

Rhethik * Note 1

Spercene CF E 2462

Sack Black * Note 1

Safe Floc 1 * Note 1

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development


Salt Flossy E 311

Sapp E 2449

Soltex Gold 1797

Starglide Gold 2395

Thermoset F/M * Note 1

Versagel HT E 2499

Versatrol HT D 4261

Zinc Oxide * Note 1

Sodium Formate E 2426

Warp water based Gold 5461

Reclaim Flocculant - REFLOC 707 * Note 1

Reclaim Surfactant - RESURF 2035 * Note 1

Bentone 38 E 2317

Calcium Chloride Flake (74% - 77%) E 5613

Calcium Chloride P94% E 5613

Caustic Soda E 2340

Circal 1000 E 2451

Circal 60/16 E 2451

Circal Y E 2451

DD * Note 1

Drispac R E 1758

Drispac SL E 1681

Duo-Vis Gold 2378

Glute 25 Silver 5898

Guar Gum E 2415

HRP D 5393

Kleen Up Silver 24536

Lime E 1132

MEG E 4775

M-I Bar E 2336

M-I Gel E 2405

Novatec F/P/S * Note 1

Potassium Chloride E 3977

Rx-03 X * Note 1

Safe-Cor Gold 2496

Safe-Scav Na E 2434

Safe-Solv E Gold 4123

Safe-Surf WN Gold 2362

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development


Soda Ash E 1158

Sodium Bicarbonate E 1135

Saraline 185V D 24090

Lao 14-16-18 * Note 1

Flowzan E Gold 1773 & 1683

Form A Plug II E 23447

Form A Set AK * Note 1

Form A Set XL * Note 1

Form A Set Acc * Note 1

Form A Set Ret * Note 1

Form A Squeeze E 5168

G Seal/ Gseal Fine E 2332

OS-1L E 1925

Sodium Bromide E 1136

Potassium Formate E 3818

Safesurf O * Note 1

Polyplus Liquid (>30%) * Note 1

Asphasol Supreme Gold 22997

Completions

Aldacide Silver 269

Econoprop/Carboprop E 2805

EFS-1 Gold 23687

FDP-S714-04 E 24423

HAI-202 Gold 4487

HCl E 2129

HT Breaker Gold 2094

KCl E 2142

LGC-37UC Gold 24419

NaBr E 1136

WG-37 E 23680

K-34 E 2140

Testing

Transaqua HT2 D 4082

Methanol E 4776

Monoethyleneglycol E 4775

Subsea

Oceanic HW740R D 24287

Cementing

Antifoam Agent D175A Gold 11958

Anti-Settling Agent D153 E 1599

B275 (Dye) Gold 3047

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development


CemCRETE* Dry Blend D962 E 23972

Cement Additive D095 E 3047

Cement Class G D907 E 1603

Cement Retarder D110 Gold 1664

DeepCRETE E * Note 1

Ezeflo F103 Gold 1765

Fluid Loss Control Additive D193 Gold 3997

Gasblok* Gas Migration Control Additive D600G Gold 3127

Gasblok* LT D500 Gold 1769

Liquid Retarder D081 E 1593

Litefil D124 E 1707

Low Temperature Cement Set Enhancer D186 Gold 24422

Low Temperature Dispersant D185 Gold 3158

Low-Temperature Liquid Dispersant D145A Gold 1633

Mudpush* II Spacer D182 Gold 24030

Multi-Temperature Cement Retarder D161 Gold 1489

Mutual Solvent U066 Gold 1629

Silicate Additive D075 E 1590

Uniflac* L D168 Gold 1814

*Note 1- These products are currently under assessment. Products shall have a CHARM/OCNS rating of Gold or Silver or D or E or shall be substituted for an equivalent product.

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

Appendix 3

ExxonMobil Environment Policy

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

ExxonMobil Environment Policy

It is the policy of the Company to conduct its business in a manner that is compatible with the balanced environmental and economic needs of the communities in which it operates.

The Company is committed to continuous efforts to improve environmental performance throughout its operations.

Accordingly, the policy is to:

Comply with all applicable environmental laws and regulations and apply responsible standards where laws and regulations do not exist.

Encourage concern and respect for the environment, emphasise every employee's responsibility in environmental performance and ensure appropriate operating practices and training.

Work with government and industry groups to foster timely development of effective environmental laws and regulations based on sound science and considering risks, costs and benefits and effects on energy and product supply.

Manage its business with the goal of preventing incidents and of controlling emissions and wastes to below harmful levels; design, operate and maintain facilities to this end.

Respond quickly and effectively to incidents resulting from its operations, cooperating with industry organisations and authorised government agencies.

Conduct and support research to improve understanding of the impact of its business on the environment, to improve methods of environmental protection, and to enhance its capability to make operations and products compatible with the environment.

Communicate with the public on environmental matters and share its experience with others to facilitate improvements in industry performance.

Undertake appropriate reviews and evaluations of its operations to measure progress and to ensure compliance with this policy.

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

Appendix 4

EPBC Act Protected Matters Report

G1-NT-PLNX0001089

EPBC Act Protected Matters Report: CoordinatesThis report provides general guidance on matters of national environmental significance and other mattersprotected by the EPBC Act in the area you have selected.

Information on the coverage of this report and qualifications on data supporting this report are containedin the caveat at the end of the report.

Information about the EPBC Act including significance guidelines, forms and application process detailscan be found at http://www.environment.gov.au/epbc/assessmentsapprovals/index.html

This map may contain data which are©Commonwealth of Australia (GeoscienceAustralia), ©PSMA 2010

CoordinatesBuffer: 10.0Km

Report created: 31/05/11 16:27:22

Summary

DetailsMatters of NESOther matters protected bythe EPBC ActExtra Information

Caveat

Acknowledgements

G1-NT-PLNX0001089

http://www.environment.gov.au/index.html

SummaryMatters of National Environmental Significance

This part of the report summarises the matters of national environmental significance that may occur in,or may relate to, the area you nominated. Further information is available in the detail part of the report,which can be accessed by scrolling or following the links below. If you are proposing to undertake anactivity that may have a significant impact on one or more matters of national environmental significancethen you should consider the Administrative Guidelines on Significance - seehttp://www.environment.gov.au/epbc/assessmentsapprovals/guidelines/index.html.

World Heritage Properties: None

National Heritage Places: None

Wetlands of InternationalSignificance (RamsarWetlands):

None

Great Barrier Reef MarinePark:

None

Commonwealth Marine Areas: Relevant

Threatened EcologicalCommunitites:

None

Threatened Species: 7

Migratory Species: 13

Other Matters Protected by the EPBC Act

This part of the report summarises other matters protected under the Act that may relate to the area younominated. Approval may be required for a proposed activity that significantly affects the environment onCommonwealth land, when the action is outside the Commonwealth land, or the environment anywherewhen the action is taken on Commonwealth land. Approval may also be required for the Commonwealthor Commonwealth agencies proposing to take an action that is likely to have a significant impact on theenvironment anywhere.

The EPBC Act protects the environment on Commonwealth land, the environment from the actions takenon Commonwealth land, and the environment from actions taken by Commonwealth agencies. Asheritage values of a place are part of the 'environment', these aspects of the EPBC Act protect theCommonwealth Heritage values of a Commonwealth Heritage place and the heritage values of a place onthe Register of the National Estate. Information on the new heritage laws can be found athttp://www.environment.gov.au/heritage/index.html

Please note that the current dataset on Commonwealth land is not complete. Further information onCommonwealth land would need to be obtained from relevant sources including Commonwealthagencies, local agencies, and land tenure maps.

A permit may be required for activities in or on a Commonwealth area that may affect a member of alisted threatened species or ecological community, a member of a listed migratory species, whales andother cetaceans, or a member of a listed marine species. Information on EPBC Act permit requirementsand application forms can be found at http://www.environment.gov.au/epbc/permits/index.html.

Commonwealth Lands: None

Commonwealth HeritagePlaces:

None

Listed Marine Species: 8

Whales and Other Cetaceans: 22

G1-NT-PLNX0001089

Critical Habitats: None

Commonwealth Reserves: None

Report Summary for Extra Information

This part of the report provides information that may also be relevant to the area you have nominated.

Place on the RNE: None

State and Territory Reserves: None

Regional Forest Agreements: None

Invasive Species: None

Nationally ImportantWetlands:

None

DetailsMatters of National Environmental Significance

Commonwealth Marine Areas [ Resource Information ]

Approval may be required for a proposed activity that is likely to have a significant impact on theenvironment in a Commonwealth Marine Area, when the action is outside the Commonwealth MarineArea, or the environment anywhere when the action is taken within the Commonwealth Marine Area.Generally the Commonwealth Marine Area stretches from three nautical miles to two hundred nauticalmiles from the coast.

EEZ and Territorial Sea

Threatened Species [ Resource Information ]

Name Status Type of PresenceMAMMALSBalaenoptera musculusBlue Whale [36] Endangered Species or species habitat may occur within areaMegaptera novaeangliaeHumpback Whale [38] Vulnerable Species or species habitat may occur within areaREPTILESCaretta carettaLoggerhead Turtle [1763] Endangered Species or species habitat may occur within areaChelonia mydasGreen Turtle [1765] Vulnerable Species or species habitat may occur within areaDermochelys coriaceaLeatherback Turtle, LeatheryTurtle, Luth [1768]

Endangered Species or species habitat may occur within area

Eretmochelys imbricataHawksbill Turtle [1766] Vulnerable Species or species habitat may occur within areaNatator depressusFlatback Turtle [59257] Vulnerable Species or species habitat may occur within area

Migratory Species [ Resource Information ]

Name Status Type of PresenceMigratory Marine SpeciesBalaenoptera bonaerensisAntarctic Minke Whale, Species or species habitat may occur within area

G1-NT-PLNX0001089

http://www.environment.gov.au/metadataexplorer/full_metadata.jsp?docId=%7B25D465DA-EF4A-4C23-B5E2-D87208DDE964%7D&loggedIn=false

http://www.environment.gov.au/metadataexplorer/full_metadata.jsp?docId=%7B57A51483-6640-4106-A788-DD9005A4AE47%7D&loggedIn=false

http://www.environment.gov.au/cgi-bin/sprat/public/publicspecies.pl?showprofile=Y&taxon_id=36









Dark-shoulder Minke Whale[67812]Balaenoptera edeniBryde's Whale [35] Species or species habitat may occur within areaBalaenoptera musculusBlue Whale [36] Endangered Species or species habitat may occur within areaCaretta carettaLoggerhead Turtle [1763] Endangered Species or species habitat may occur within areaChelonia mydasGreen Turtle [1765] Vulnerable Species or species habitat may occur within areaDermochelys coriaceaLeatherback Turtle, LeatheryTurtle, Luth [1768]


Eretmochelys imbricataHawksbill Turtle [1766] Vulnerable Species or species habitat may occur within areaIsurus oxyrinchusShortfin Mako, Mako Shark[79073]

Species or species habitat likely to occur within area

Isurus paucusLongfin Mako [82947] Species or species habitat likely to occur within area

Megaptera novaeangliaeHumpback Whale [38] Vulnerable Species or species habitat may occur within areaNatator depressusFlatback Turtle [59257] Vulnerable Species or species habitat may occur within areaOrcinus orcaKiller Whale, Orca [46] Species or species habitat may occur within areaPhyseter macrocephalusSperm Whale [59] Species or species habitat may occur within area

Other Matters Protected by the EPBC Act

Listed Marine Species [ Resource Information ]

Name Status Type of PresenceReptilesAipysurus laevisOlive Seasnake [1120] Species or species habitat may occur within areaCaretta carettaLoggerhead Turtle [1763] Endangered Species or species habitat may occur within areaChelonia mydasGreen Turtle [1765] Vulnerable Species or species habitat may occur within areaDermochelys coriaceaLeatherback Turtle, LeatheryTurtle, Luth [1768]


Eretmochelys imbricataHawksbill Turtle [1766] Vulnerable Species or species habitat may occur within areaHydrophis elegansElegant Seasnake [1104] Species or species habitat may occur within areaNatator depressusFlatback Turtle [59257] Vulnerable Species or species habitat may occur within areaPelamis platurus

G1-NT-PLNX0001089






















Yellow-bellied Seasnake [1091] Species or species habitat may occur within areaWhales and Other Cetaceans [ Resource Information ]

Name Status Type of PresenceMammalsBalaenoptera bonaerensisAntarctic Minke Whale,Dark-shoulder Minke Whale[67812]

Species or species habitat may occur within area

Balaenoptera edeniBryde's Whale [35] Species or species habitat may occur within areaBalaenoptera musculusBlue Whale [36] Endangered Species or species habitat may occur within areaDelphinus delphisCommon Dophin, Short-beakedCommon Dolphin [60]


Feresa attenuataPygmy Killer Whale [61] Species or species habitat may occur within areaGlobicephala macrorhynchusShort-finned Pilot Whale [62] Species or species habitat may occur within areaGrampus griseusRisso's Dolphin, Grampus [64] Species or species habitat may occur within areaKogia brevicepsPygmy Sperm Whale [57] Species or species habitat may occur within areaKogia simusDwarf Sperm Whale [58] Species or species habitat may occur within areaLagenodelphis hoseiFraser's Dolphin, SarawakDolphin [41]


Megaptera novaeangliaeHumpback Whale [38] Vulnerable Species or species habitat may occur within areaMesoplodon densirostrisBlainville's Beaked Whale,Dense-beaked Whale [74]


Orcinus orcaKiller Whale, Orca [46] Species or species habitat may occur within areaPeponocephala electraMelon-headed Whale [47] Species or species habitat may occur within areaPhyseter macrocephalusSperm Whale [59] Species or species habitat may occur within areaPseudorca crassidensFalse Killer Whale [48] Species or species habitat may occur within areaStenella attenuataSpotted Dolphin, PantropicalSpotted Dolphin [51]


Stenella coeruleoalbaStriped Dolphin, EuphrosyneDolphin [52]


Stenella longirostrisLong-snouted Spinner Dolphin[29]


Steno bredanensisRough-toothed Dolphin [30] Species or species habitat may occur within area

G1-NT-PLNX0001089






















Tursiops truncatus s. str.Bottlenose Dolphin [68417] Species or species habitat may occur within areaZiphius cavirostrisCuvier's Beaked Whale,Goose-beaked Whale [56]


Extra Information

CaveatThe information presented in this report has been provided by a range of data sources as acknowledged atthe end of the report.

This report is designed to assist in identifying the locations of places which may be relevant indetermining obligations under the Environment Protection and Biodiversity Conservation Act 1999. Itholds mapped locations of World Heritage and Register of National Estate properties, Wetlands ofInternational Importance, Commonwealth and State/Territory reserves, listed threatened, migratory andmarine species and listed threatened ecological communities. Mapping of Commonwealth land is notcomplete at this stage. Maps have been collated from a range of sources at various resolutions.

Not all species listed under the EPBC Act have been mapped (see below) and therefore a report is ageneral guide only. Where available data supports mapping, the type of presence that can be determinedfrom the data is indicated in general terms. People using this information in making a referral may need toconsider the qualifications below and may need to seek and consider other information sources.

For threatened ecological communities where the distribution is well known, maps are derived fromrecovery plans, State vegetation maps, remote sensing imagery and other sources. Where threatenedecological community distributions are less well known, existing vegetation maps and point location dataare used to produce indicative distribution maps.

For species where the distributions are well known, maps are digitised from sources such as recoveryplans and detailed habitat studies. Where appropriate, core breeding, foraging and roosting areas areindicated under 'type of presence'. For species whose distributions are less well known, point locations arecollated from government wildlife authorities, museums, and non-government organisations; bioclimaticdistribution models are generated and these validated by experts. In some cases, the distribution maps arebased solely on expert knowledge.

Only selected species covered by the following provisions of the EPBC Act have been mapped:- migratory andmarine

The following species and ecological communities have not been mapped and do not appear in reportsproduced from this database:

- threatened species listed as extinct or considered as vagrants- some species and ecological communities that have only recently been listed- some terrestrial species that overfly the Commonwealth marine area- migratory species that are very widespread, vagrant, or only occur in small numbers.

The following groups have been mapped, but may not cover the complete distribution of the species:- non-threatened seabirds which have only been mapped for recorded breeding sites;- seals which have only been mapped for breeding sites near the Australian continent.

Such breeding sites may be important for the protection of the Commonwealth Marine environment.

Coordinates

-19.79157 114.64435,-19.82643 114.57064

G1-NT-PLNX0001089



AcknowledgementsThis database has been compiled from a range of data sources. The department acknowledges thefollowing custodians who have contributed valuable data and advice:

-Department of Environment, Climate Change and Water, New South Wales-Department of Sustainability and Environment, Victoria-Department of Primary Industries, Parks, Water and Environment, Tasmania-Department of Environment and Natural Resources, South Australia-Parks and Wildlife Service NT, NT Dept of Natural Resources, Environment and the Arts-Environmental and Resource Management, Queensland-Department of Environment and Conservation, Western Australia-Department of the Environment, Climate Change, Energy and Water-Birds Australia-Australian Bird and Bat Banding Scheme-Australian National Wildlife Collection-Natural history museums of Australia-Museum Victoria-Australian Museum-SA Museum-Queensland Museum-Online Zoological Collections of Australian Museums-Queensland Herbarium-National Herbarium of NSW-Royal Botanic Gardens and National Herbarium of Victoria-Tasmanian Herbarium-State Herbarium of South Australia-Northern Territory Herbarium-Western Australian Herbarium-Australian National Herbarium, Atherton and Canberra-University of New England-Ocean Biogeographic Information System-Australian Government, Department of Defence-State Forests of NSW-Other groups and individuals

The Department is extremely grateful to the many organisations and individuals who provided expertadvice and information on numerous draft distributions.

Please feel free to provide feedback via the page.Contact Us

Accessibility | | | | Disclaimer Privacy © Commonwealth of Australia HelpLast updated: Thursday, 16-Sep-2010 09:13:25 EST

Department of Sustainability, Environment, Water, Population and CommunitiesGPO Box 787Canberra ACT 2601 Australia+61 2 6274 1111 ABN

| |Australian Government

G1-NT-PLNX0001089

http://www.environment.nsw.gov.au/nationalparks/

http://www.dse.vic.gov.au/dse/index.htm

http://www.dpiw.tas.gov.au/inter.nsf/Home/1?Open

http://www.environment.sa.gov.au/

http://www.nt.gov.au/nreta/parks/

http://www.derm.qld.gov.au/

http://www.dec.wa.gov.au/

http://www.environment.act.gov.au/

http://www.birdsaustralia.com.au

http://www.environment.gov.au/biodiversity/science/abbbs

http://www.csiro.au/places/anwc.html

http://museumvictoria.com.au/

http://australianmuseum.net.au/

http://www.samuseum.sa.gov.au/

http://www.qm.qld.gov.au/

http://www.ozcam.org.au/

http://www.derm.qld.gov.au/wildlife-ecosystems/plants/queensland_herbarium/

http://www.rbgsyd.nsw.gov.au/science/Herbarium_and_resources

http://www.rbg.vic.gov.au

http://www.tmag.tas.gov.au

http://www.environment.sa.gov.au/botanicgardens/

http://www.nt.gov.au/nreta/parks/

http://www.dec.wa.gov.au/content/category/41/831/1821/

http://www.anbg.gov.au/cpbr

http://www.une.edu.au

http://www.iobis.org/

http://www.defence.gov.au/

http://www.forest.nsw.gov.au/

http://www.environment.gov.au/epbc/contacts/index.html

http://www.environment.gov.au/about/accessibility.html

http://www.environment.gov.au/about/disclaimer.html

http://www.environment.gov.au/about/privacy.html

http://www.environment.gov.au/about/copyright.html

http://www.environment.gov.au/about/help.html

http://www.environment.gov.au/index.html

http://www.environment.gov.au/about/business/index.html

http://www.australia.gov.au/

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

Appendix 5

ExxonMobil Qualitative Risk Matrix

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

SOURCE EAPL Risk Assessment & Management System Manual (Revision 4.2) SECT090 APP-A

G1-NT-PLNX0001089

JANSZ-IO DRILLING

ENVIRONMENT PLAN


Development

Appendix 6

Jansz-Io Oil Spill Contingency Plan

G1-NT-PLNX0001089

jansz-io drilling environment plan

Documents