fpso redeployment

Design Considerations for FPSO Redeployment – FPSO Congress 2015

Presentation by - Noel Denton

Background to FPSO Redeployment

Challenges of FPSO Redeployment

Case Study: Front Puffin

Case Study: OSX-1

Case Study: Berantai

Conclusions

Design Considerations for FPSO Redeployment

Contents

Background FPSO Redeployment

History

FPSO East Fortune (Songa Floating Production) conversion to

FPSO Berantai (Petrofac Floating Production)

• FPSOs offered the industry a

technology that could provide a large

processing facility with the ability to

redeploy

• Redeployments have been achieved

successfully on a number of occasions

in the industry – but it is not always as

straightforward as it seems.

• There have been 24 redeployments in

the last 10 years

• Some vessels have been redeployed

on multiple occasions

• The range of modifications required

can be from minimal to extensive such

as new topsides and jumboisation of

the hull – this requires a lot of careful

planning at the start.

Background of FPSO Redeployment

From Crystal Sea (Crystal Production), to BW Carmen

(BWO) to BW Athena (BWO)


Why an FPSO?

• Potentially fastest route to first oil when compared to other

equivalent topsides substructure options

• Leased option can improve project economics especially for

shorter field lifes

• Short field life or uncertain reservoir performance makes leasing

with extension options attractive

• Lack of infrastructure for export and flexibility to deliver product to

the global market

• Offers the option to be disconnectable in regions with adverse

weather

• Readily deployable in a range of water depths from shallow to

deepwater

• Large topsides carrying capacity

• Storage available to mitigate process interruptions


Why redeploy?

• Shortened project execution schedule leading to earlier first oil

• Potential reduced day-rate when compared to fresh conversion /

new build

• Proven service history

Challenges for FPSO Redeployment

Technical

Hull

• Global strength and fatigue needs to be checked including stability check if new

modules are added;

• Steel replacement for life extension and coating repairs;

• Change of class / flag / regulatory regime can require modifications to the hull and

accommodation which are difficult to estimate until arrival at the shipyard.

Mooring

• Is the mooring type applicable for the new deployment:

• Is the water depth suitable for a disconnectable mooring?

• Does the FPSO require to be spread moored or turret moored?

• Is the turret suitable:

• Are the loads similar?

• Are the number of risers and umbilicals similar?


Technical

Topsides:

• It is more than just checking the name plate capacities!

• Gas compression systems are sensitive to composition and changes to pressure

ratios;

• Material selection should be verified based on CO2 and H2S content. It is also

important to establish a baseline condition for the vessels and piping to establish

remaining life;

• Flare system design;

• Flow limitation through the turret and swivel paths including erosion issues for

sand content;

• Water cut;

• Is it a heavy crude?

• Increased power requirements

• Increased heat load

• Tertiary treatment required


Technical

Topsides:

• Change in regulatory requirements:

• Are there additional requirements for the topsides?

• Is a safety case required?

Case Studies

FPSO Front Puffin

Background

• The FP was converted in 2007 from

Shuttle Tanker to FPSO and then

deployed as an FPSO for Puffin field

• FPSO Front Puffin was deployed at

AC/P22 Block North of Western

Australia

• FPSO Front Puffin is now to be

redeployed to the Aje Field in West

Africa

• The mooring and hull require minimal

modification despite moving from

Australia to West Africa

• The topsides require additional modules

to fulfill the field requirements

Case Study

FPSO Front Puffin (Rubicon Offshore International)

FPSO Front Puffin

Modifications

• Replacement of existing gas lift compressor

package with new package.

• Addition of gas dehydration package

• Addition of fiscal metering skid

• Addition of subsea chemical injection package

• Upgrade of methanol injection package

• Addition of subsea master control system

• Addition of subsea hydraulic power unit

• Upgrade of control system for new packages

• Upgrade of power distribution system for new

packages

• Integration piping

• FEED study for pre-engineering for future

upgrade scope (gas fuelled power generation)

Case Study


FPSO Front Puffin

Challenges and solutions

• Gap analysis – At the earliest opportunity conduct a

gap analysis to quantify the scope and identify any

major hurdles.

• Gas compression – replace existing units and add

a gas dehydration unit

• Change in Fiscal Regime – New gas metering

required

• Congested deck area requiring careful analysis of

support locations and tie-in points – utilisation of

3D modelling to ensure efficient implementation

• Multiple contractors – Successful use of the

integrated team approach to minimise interface

issues

• Upgrade of existing facility – Close liaison with

operations to ensure as built information is robust

when being implements into new configuration

Case Study


OSX-1 FPSO

Background

Case Study

FPSO: OSX-1 FPSO

Location: Brazil

Client: Keppel / BW Offshore

Upgrade of the new-build Nexus 1 FPSO to

make it suitable for the OSX Waimea heavy oil

field (API 17.6) offshore Brazil

Involves 7 new modules including

• Inlet Manifold

• Crude Heating

• Water Injection

• Fuel Gas Compression

• Power Module

OSX-1 FPSO

Background

• The Nexus-1 FPSO was developed as a

harsh environment generic FPSO

• Although it was never deployed, it can

be seen that even a generic FPSO

required extensive upgrade to make it

suitable for its eventual deployment

• The Nexus-1 FPSO became the OSX-1

• The heavy oil characteristics meant that

extensive heating and tertiary treatment

were required to achieve the crude

specification

Case Study

everything in pink is a change

OSX-1 FPSO

• Extensive modification was required to

the topsides

Modifications

Case Study

OSX-1 FPSO

Tertiary Treatment / Options for Treatment for Heavy Oil

• VIEC Internals – These can be

retrofitted to existing separators to

improve separation of oil and water

• Compact Electrostatic Coalescer – This

can be used upstream of existing

separation to promote increased droplet

sizes to improve separation

• Modified Internals for the Electrostatic

Coalescer – This can be used to

increase the allowable water cut and/or

to improve separation

• Centrifuge – An established technology

for treatment of heavy oils / tar

Case Study

FPSO: Berantai

Location: Malaysia

Client: Keppel / Petrofac / Petronas

Upgrade of the East Fortune FPSO to make it

suitable for Berantai Field in Malaysia

Includes 9 new modules

(approximately 5000 Te)upgrading

Berantai FPSO

Background

Berantai FPSO

Background

• FPSO Berantai was developed from the

FPSO East Fortune

• FPSO East Fortune was a generic

FPSO which was never deployed

• As with OSX-1 although it was a generic

FPSO it required extensive modification

for its eventual deployment

• The historic difficulty of successfully

employing the generic FPSO concept

demonstrates the fundamental difficulty

of matching the topsides to the field

(other economic factors also impacted

the success of the concept)

• The versatility of load bearing capacity

of the ship-shaped hull is demonstrated

by the dramatic increase in the topsides

between the two concepts.

Case Study

FPSO East Fortune (Songa Floating Production) conversion to

FPSO Berantai (Petrofac Floating Production)

Berantai FPSO Before and After

FPSO before upgrade FPSO after upgrade

FPSO Redeployment

Conclusions

• The FPSO remains an attractive option for field development due to its inherent

ability to be redeployed

• When considering redeployment the entire FPSO needs to be examined through

thorough gap analysis – mooring, risers, hull, marine systems, safety systems,

accommodation and topsides.

• Although redeployment is not necessarily straightforward with careful planning

and robust engineering it can be achieved successfully

Noel Denton

T 96271998

[email protected]

fpso redeployment

Engineering