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DNV GL © 2017 15 October 2018 SAFER, SMARTER, GREENERDNV GL © 2017
15 October 2018
DNV GL
Design Considerations – Mexico Subsea Pipelines
1
Mexican Regulations, DNV GL Services
DNV GL © 2017 15 October 2018
PIPELINE DESIGN CONSIDERATIONS
Agenda
2
24 October, 2018
I DNV GL IN MEXICO OVERVIEW1
MEXICAN INSTITUTIONAL FRAMEWORK2
REGULATORY OVERVIEW MEXICO, PIPELINES 3
DNV GL SUPPORT FOR REGULATORY REQUIREMENTS, PIPELINE SERVICES4
5
QUESTIONS6
DNV GL © 2017 15 October 20183
DNV GL © 2017 15 October 2018
DNV GL in Mexico
4
20+ years in Mexico
100+ local employees
4 Local Offices with head office in Mexico City
Multi-discipline Team
Working in collaboration with ASEA, CRE,
SEMARNAT (PROFEPA) in the process of creation
of various regulations
Good relationship with SENER (Energy Minister),
CRE, CNH, ASEA, SEMARNAT (PROFEPA)
Authorized by Regulators to provide verification in
accordance with multiple National Standards
DNV GL © 2017 15 October 2018
DNV GL Mexico Accreditations
5
Statutory Verification Before the opening of the upstream Oil & Gas sector and ASEA creation, the
authorities in Mexico used a statutory verification scheme to achieve compliance
with the different national standards required by the regulators, (i.e. SENER, CRE,
SEMARNAT, STPS…).
DNV GL in Mexico is authorized by the regulators to provide verification of the
below national standards:
Natural Gas Facilities:
• NOM-001-SECRE
• NOM-002-SECRE
• NOM-003-SECRE
• NOM-007-SECRE
• NOM-013-SECRE
Pressure Vessels:
• NOM-020-STPS
Electrical Facilities:
• NOM-001-SEDE-2005
LPG Facilities:
• NOM-015-SECRE
• NOM-004-SECRE
DNV GL © 2017 15 October 20186
DNV GL © 2017 15 October 2018
Mexican Regulatory Institutions
7
Regulations
SEMARNAT – Ministry of Environment
SHCP – Ministry of Finances and Taxes
SCT – Ministry of Transportation
STPS – Ministry of Labour
SENER – Ministry of Energy
CENACE – Energy Control Center
CENAGAS – Natural Gas Regulatory
PEMEX – National Oil Company
CFE – Enterprise State Company for
Power, Transmission and Electrical
Distribution
CRE – Regulator for Non- Hydrocarbon
Energy
CNH – Regulatory for Hydrocarbon E&P
ASEA – Regulator for HSE
Decentralized
Entities
Enterprise
State
Companies
Regulatory
Bodies
Ministries
DNV GL © 2017 15 October 2018
DNV GL Mexico – Current Regulatory Authorizations (new scheme)
▪ Authorized by ASEA to perform Probabilistic Economical Damage for Loss
of Well Control (Only party to be authorized)
▪ Authorized by ASEA to provide Certification of elements of SASISOPA (Only
international company to be authorized)
▪ Authorized by ASEA to perform Third Party Services for Upstream
▪ Under approval by ASEA to perform Audits of the performance of the
SASISOPA
▪ In dialogue with CNH for 3rd party approval for Well Certification
8
DNV GL © 2017 15 October 20189
DNV GL © 2017 15 October 2018
Mexico Field Development Typical Timeline – Licensing and Approvals
10
Winner
Exploration Plan
Transition
Phase
180 Days
CNH
Approval
Initial Exploration
Period
Notification
CNH
Discovery
Notice
120 Days
120 Days 4 Years 30 Days
Evaluation
Plan
(Drilling)
180 Days
CNH
Approval
60 Days
Evaluation
Activities
3 Years
Commercial
Discovery
Development
Plan
90 Days 2 Years
Commercial
Notification
120 Days
CNH
Approval
34 Years 35 Years
Production
Final Transition
Phase
1.° Additional Exploration Period (3 Years)
2° Additional Exploration Period (3 Years)
5 Years 10 Years
First Extension
Phase
Second Extension
Phase
(SASISOPA
EBL
SIE)
Activity / Phase
Owner / Operator
Activity
Approval / Notification
by Regulator
DNV GL © 2017 15 October 2018
Regulations and Governance Roles for Project Phases
11
Winner
Exploration Plan Production
SASISOPA
Environmental
Baseline
Social Impact
Evaluation
E&E
DEVELOPMENT
PLANS
Initial Exploration
Period
DRILLING WELL
REGULATION
RESERVOIR
QUANTIFICATION
HYDROCARBONS
METERING
Development
Plan
EXPLOITATION OF
NATURAL GAS
Insurance E&E Incidents &
Accidents notice
Incidents &
Accidents RCA
SURFACE RECOGNITION,
E&E OF HC SASISOPA
Winner
DNV GL © 2017 15 October 2018
Regulatory Framework for Floaters in Mexico – DNV GL Interpretation
12
Process Plant:
Risk Based Verification
(DNVGL-SE-0474)
Studies for ALARP:
HAZID, EERA, FERA, QRA Noise,
Well release and Spill (CFD), etc.
Hull, Mooring & Marine
Systems:
Class Notation + Statutory
ASEA
Regulatory
Compliance
As if PROD+Existing NOMs/
Applicability
(e.g. Pressure vessels,
Electrical, Lifting appliances
,Metering, discharge
+
DNV GL © 2017 15 October 2018
Typical Standards included in ASEA E&E RegulationsNORSOK N-006, 2nd
Edition, 2015Assessment of structural integrity for existing offshore load-bearing structures. NORSOK N-006, Second Edition, April 2015.
Equipment and Materials
API 14A Specification for Subsurface Safety Valve Equipment. Twelfth Edition, January 2015.
ANSI/API 6A Specification for Wellhead and Christmas Tree Equipment, Twentieth Edition October 2010.
API 6AV1 Specification for Validation of Wellhead Surface Safety Valves and Underwater Safety Valves for Offshore Service. Second Edition, February 2013.
API 53 Standard, Blowout Prevention Equipment Systems for Drilling Wells. Fourth Edition, November 2012.
NFPA31 Standard for the Installation of Oil-Burning Equipment. Edition 2016.
NORSOK M-001 Materials Section. Fifth Edition, September 2014.
NORSOK M-501 Surface preparation and protective coating. Sixth Edition, February 2012.
NORSOK R-001 Mechanical Equipment NORSOK R-001. Rev. 3, Nov. 1997.
ANSI/API 12A Oil storage tanks with riveted shells.
ANSI/API 14B Recommended practices. Design, Installation, Operation, Test, and Redress of Subsurface Safety Valve Systems.
Personnel
NORSOK S-006 HSE Evaluation of contractors. Rev. 2, Dec. 2003.
Pipelines
API RP 1111 Design, Construction, Operation, and Maintenance of Offshore Hydrocarbon Pipelines (Limited Status), Fourth Edition, August 2007.
ASME B31.4-2012 Pipeline Transportation Systems for Liquids and Slurries, ASME for Pipe Pressurization, B31, November 2012.
ASME B31.8-2014 Transmission and Distribution Piping Systems, ASME for Pipe Pressurization, September 2014.
ISO 15589-2 Petroleum, petrochemical and natural gas industries — Cathodic protection of pipeline transportation systems – Part 2: Offshore Pipelines, 2012.
NORSOK M-503 Cathodic protection. Rev. 3, May 2007.
Production Operations
NORSOK I-106 Fiscal metering systems for hydrocarbon liquid and gas, First Edition, November 2014.
NORSOK U-001 Subsea production system. Fourth Edition, October 2015.
NORSOK S-003 Environmental care. Rev. 3, Dec. 2005.
Safety Management Systems
ABS Change Management for Maritime and Offshore Industries, February 2013.
API RP 75 Recommended Practice for Development of a Safety and Environmental Management Program for Offshore Operations and Facilities. Third Edition, May 2004.
DNV-OSS-300 DNV GL, Risk-Based Verification, April 2012 and associated series of standards (301,302,304,306 and 307)
NORSOK P-002 Process System Design. First Edition, August 2014.
NORSOK S-001 Technical Safety. Fourth Edition, February 2008.
13
DNV GL © 2017 15 October 2018
What do we have today?
14
• All Mexican offshore pipelines were designed, built
and operated by Pemex PEP
• Offshore production in Mexico started ca. 40 years
ago
• The pipeline network grew with the development of
new fields and the extension of existing ones
• There are oil, gas and N2-lines
• The lines are not regulated (yet) and remain
property of Pemex
• New pipeline capacity will have to be constructed
by the new operators, which will be regulated
DNV GL © 2017 15 October 2018
MEXICO ENERGY REFORM: THE TRANSFORMATION
15
DNV GL © 2017 15 October 2018
New Mexican Revolution
16
• Rising Energy demand in Mexico
• Inexpensive, abundant US shale gas
• Drive to cleaner energy generation
• Falling gas production of Pemex
5 year plan for to:
• Double the length from 10k to 20k kms
• Private investment of 10 BUSD
• Anchored by CFE contracts
• First private offshore pipeline
• US Gas Exports 2016: 3.7 B$ / 4 BCFD
DNV GL © 2017 15 October 2018
Energy Reform 2013 – opening & reform
17
Round 1.4, Deepwater
Round 1.1, shallow
▪ The Energy Reform ended 75 years of
a Pemex Monopoly in Hydrocarbon
activities
▪ We have had six license rounds for
onshore, shallow- and deep water
fields that overall were considered
successful
▪ 70% award rate/ 39 contracts/ 26
contractors/ 14 countries/ 49 BUSD
expected investment
▪ New Operators: Statoil, DEA, CNOOC,
Chevron, Total, Murphy, BHP Billiton,
PC Carigali, ENI, ..
▪ New Regulators were established
DNV GL © 2017 15 October 2018
New Institutional Environment
18
DNV GL © 2017 15 October 2018
New Regulatory Structure
19
DNV GL © 2017 15 October 2018
CRE – ASEA: Who is responsible for what?
▪ Regulates the midstream sector
from a commercial perspective
▪ Issues and enforces the
compliance with relevant
Regulations (NOMs, DACGs)
▪ Issues and validates Transport
permits, et al
▪ Regulates and administers the
open access to transport capacity
▪ Sets Tariffs: Transport, Distr.,
Storage
▪ Oversees Metering activities
20
▪ Regulates the Hydrocarbons
Sector related to Industrial
Safety and Protection of the
Environment
▪ Issues Licenses to Operators
▪ Requires the implementation and
upkeep of a SASISOPA (sim.
SEMS) for all operators
▪ Issues and enforces the
compliance with relevant
Regulations (NOMs, DACGs)
▪ Accident investigations (RCA)
DNV GL © 2017 15 October 2018
Mexican Regulations for Subsea Pipelines
▪ There are NO dedicated Subsea Pipeline Regulations in Mexico at this
point in time!!
▪ For gas pipelines CRE and ASEA require compliance with the NOM-007-SECRE-
2010, which was based originally on ASME-B31.8, and does not address subsea
pipeline specific items.
▪ NOM-007 does not reference directly any International subsea pipeline code.
▪ ASEA has issued Upstream regulations and in Art. 73 they require that Pipelines
need to be designed, installed and maintained in a way that industrial- and
operational safety is ensured and the environment protected.
▪ ASEA refers to API-RP-1111 as one of the obligatory standards listed in Annex 1
of the Upstream regulations.
21
DNV GL © 2017 15 October 2018
Mexico Offshore Development Summary
▪ Mexico has initiated a comprehensive Energy Reform and is
opening up the complete hydrocarbons sector
▪ Gas demand in Mexico is expected to grow another 30% over
the next 10 years, more pipelines will be necessary
▪ An important part of the reform is a redesign of the regulatory
environment, including the establishment of new regulators and
re-defining existing ones.
▪ De-coupling of commercial and Safety & Environmental aspects
and responsibilities
▪ Authorities regulating offshore pipelines are CRE and ASEA
▪ Currently and for the near future there are no specific
Offshore Pipeline Regulations, what is used are NOMs
coupled with international regulations (API, DNV GL, etc.)
22
DNV GL © 2017 15 October 2018
Mexico Natural Gas
23
DNV GL © 2017 15 October 2018
Codes and Standards-CFE
24
The Natural Gas Transmission System and the Carrier must
comply with the following:
The General Law of Ecological Balance and Environmental
Protection (Ley General de Equilibrio Ecológico y la
Protección al Ambiente, LGEEPA) and its Regulations
pertaining to the Ecological Code, Environmental Impact
Assessment, Prevention and Control of Pollution to the
Atmosphere, Pollution from Noise Emissions, and Protected
Natural Areas.
Law on the Coordinated Regulatory Agencies in Energy
Matters.
Hydrocarbons Law and its Regulations.
Regulations of the Activities Referred to in Title III of the
Hydrocarbons Law
Federal Electricity Commission Law and its Regulations.
Federal Law on Metrology and Standardization.
NOM-001-SECRE-2010. NG Specifications;
NOM-007-SECRE-2010. NG Transmission.
NOM-008-SECRE-1999. External Corrosion control
NACE Standards
ASME Standards
ASTM Publications
API
• NOM-007-SECRE-2010.
• NOM-001-SECRE-2010.
DNV GL © 2017 15 October 2018
On-Shore: CFE Requirements- UV Gas Specification (NOM-001)
25
Summary:
1. Document review and Inspection (materials and
components in evaluation of Natural Gas spec).
2. Verify Testing methods & ensure they are duly
validated
3. Traceability
4. Equipment calibrations and capability of personnel
5. Documentation delivered by the manufacturer
6. Procedure for installation, operation and
maintenance
7. Results of testing and control statistics
8. Field verification to ensure verified procedures are
applied.
DNV GL © 2017 15 October 2018
NOM-007 (2010)7.1.2 In the pipeline design must consider aspects such as:
a) Physical and chemical characteristics of natural gas, according to NOM-
001-SECRE-2010, natural gas Specifications
b) Maximum operating pressure, and
c) Maximum operating temperature.
7.2 Additional loads. a) live loads such as the weight of natural gas
(consider the weight of water to effect the calculation), snow, ice and wind,
among others;
b) charges for cyclical vehicle traffic;
c) dead loads such as the weight of the pipe, coatings, fillers, valves and
other accessories not supported;
d) stresses caused by earthquakes;
e) Vibration and / or resonance;
f) Efforts settlements or landslides caused by unstable soils in regions;
g) effects of thermal expansion and contraction;
h) Movement of equipment connected to the pipeline;
i) Efforts caused by river currents or storm;
j) Efforts caused at intersections with roads;
k) safety factor for population density (F), in accordance with paragraph
7.10 of this Standard;
l) Factor joint efficiency (E), in accordance with paragraph 7.11 of this
Standard;
m) additional thickness by natural wear or corrosion margin.
26
HydroTest:A 1.25 times the MPOP location for class 1 and1.5 times the MPOP location for classes 2, 3 and 4.
Class Location based on No. of buildings and Occupancy
Class location Design factor (F)
1 0.72
2 0.60
3 0.50
4 0.40
Table 2. Factor design by population density
Change in class location. Study required. When an increase in population density it will cause a possible change in class location and should conduct a study to determine register:
DNV GL © 2017 15 October 2018
On-Shore: CFE Requirements- NOM-007
27
Summary:
1. Accredited and approved person
2. In the absence of official Mexican standard or
Mexican standard applicable =International
standards
3. Document review and Inspection (materials
and components in evaluation of Natural Gas
spec).
4. Develop Verification program consistent with
Construction/ operation.
5. Document Review
✓ Design
✓ Materials and Equipment
✓ Construction and Testing
✓ Operation and Maintenance Safety
6. On-shore pipeline
DNV GL © 2017 15 October 2018
PIPELINE REGULATIONS
28
On-Shore Off-Shore
Mexico USA Mexico USA
CFE, CRE
Article 134 of
Political
Constitution
Hydro-Carbon Law
Articles 2 Section
III, 4 Section XVII
and XXXVIII, 48,
50, 51, 52, 60,
65-75, 90, 123
TITLE 49—TransportationSubtitle B—OTHER REGULATIONS RELATING TO TRANSPORTATION (CONTINUED)CHAPTER I—PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED)SUBCHAPTER D—PIPELINE SAFETYPART 192—TRANSPORTATION OF NATURAL AND OTHER GAS BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS
None
BSEE & DOT
(30 CFR
250, 30 CFR
192)
Regulatory
Requirements
DNV GL © 2017 15 October 2018
DNV GL service specification (DNV-OSS-301)
31
Verification Plan for offshore PipelineWhy• To give industry guidance for developing a certification or verification plan
covering all phases of new development projects based on many years of best practice in the industry
Identifying and ranking critical elements What• Guidance for identifying and ranking critical elements of the project and
prioritising verification activities accordingly.
• Describing verification process and the activities for each of the project phases.
• Detailed scope of work tables for all phases (except operation) and all level of involvement.
DNV GL © 2017 15 October 2018
Offshore Codes & Standards
▪ DNV OSS 301 Verification and Certification of
Submarine Pipelines
▪ DNV-OS-F101 Submarine Pipeline System
▪ DNV-RP-F101 Corroded Pipelines
▪ DNV-RP-F102 Pipeline Field Joint Coating
▪ DNV-RP-F103 Cathodic Protection
▪ DNV-RP-F105 Free Spanning Pipelines
▪ DNV-RP-F106 Pipeline Coatings
▪ DNV-RP-F107 Pipeline Protection
▪ DNV-RP-F108 Fracture Control
▪ DNV-RP-F109 On-Bottom Stability
▪ DNV-RP-F110 Global Buckling
▪ DNV-RP-F111 Trawling
▪ DNV-RP-F113 Pipeline Subsea Repair
▪ DNV-RP-F116 Subsea Pipeline System Integrity
32
Frame agreement specifications
ProjectDesign premise
Auth.Rules & Reg.
Selected standards (ISO, Norsok, DNV,
API, ASME etc.)
Operation &Maint. Req's
Functional andTechnical Req's
Authorities
Operator
Standards
API 1111 - Design, Construction,
Operation and Maintenance of Offshore
Hydrocarbon Pipelines
ISO 13623 - Petroleum and natural gas
industries – Pipeline transportation
systems.
ASME B31.8 - Gas Transmission and Distribution Piping Systems
DNV GL © 2017 15 October 2018
Integrated services across the entire Pipeline life cycle
RISK MANAGEMENT ADVISORY
STRATEGYFEASIBILITY &
CONCEPT SELECTION
DESIGN
CONSTRUCTION
INSTALLATION &
COMMISSIONING
OPERATION & LIFE
EXTENTION
DECOMMIS-SIONING
TECHNICAL ADVISORY
TECHNICAL ASSURANCE (Certification, Verification & Inspection)
NOBLE DEBNTON MARINE ASSURANCE & ADVISORY
OFFSHORE CLASSIFICATION
65%65% of the world’s offshore pipelines are designed and installed to DNV’ GLs pipeline standard
DNV GL Capabilities
DNV GL © 2017 15 October 2018
Offshore Pipelines US GOMEX
34
Project References
DNV GL © 2017 15 October 2018
DNV GL Mexico Office Experience (Pipelines)
35
+20 yearsin Mexico
DNV GL MX Office have
earned more than $31.00
MUSD with services related
to pipelines.
Customers
+ 100 different customersPEMEX, GDC, Ienova, ICA Fluor, TAG pipelines, ENGIE, etc.
Experience.Team with more than +200 years in local and technical knowledge
RegulatorsParticipate as invited members for the creations of several Mexican Norms. Good relationship with CRE, ASEA and SENER
Local Offices+ 150 colleagues
4 offices (Mexico City, Villahermosa, Queretaro and Ciudad del Carmen)
860 km pipeline from US to the Centre of Mexico up to 2.1 bcfNatural Gas
DNV GL Mexico was involved in different services in the biggest pipeline ever constructed in Mexico
• PIMS Implementation Phase II South
• Verification Services (UV) Phase I
• Inspection Services for steel plate and pipeline for Phase II
• Verification Services (UV) Phase II North
Los Ramones I and II
DNV GL © 2017 15 October 2018
Mexico Main Pipeline Projects
36
Date of Assignation
Client Scope of Work Pipeline Service Location
2014-oct-02 IEPI MéxicoInspection / Certification Services of material
of line pipeLos Ramones Fase II North and
SouthInspection / Certification Services Mexico/China
2014-dic-16 ICA FLUOR, S. DE R.L. DE C.V. Implementation of PIMs Los Ramones Fase II RBI / AIM / GaliomSan Luis Potosi -
Queretaro -Guanajuato
2014-jun-25Gasoductos de Chihuahua, S. de
R.L. de C.V.Implementation of RBI with Galiom
(Technical Advisory + Galiom)Several GDC pipelines and
compression stationsRBI / AIM / Galiom Cd. de México
2006- mar-03 Green Energy Supervision, inspection and Quality ControlEl Sauz - San Miguel de Allende,
GtoVerification Unit Natural Gas Queretaro
2015-feb-03Gasoductos de Chihuahua, S de
R.L. de C.V.Verification Services for the Transport
SystemLos Ramones Fase I Verification Unit Natural Gas Various
DNV GL © 2017 15 October 201837
DNV GL © 2017 15 October 2018
Key Pipeline Design Considerations
▪ Pipeline routing, survey & Geotechnical
▪ Wall thickness
▪ On-bottom Stability
▪ Fatigue
– VIV & Allowable Free Span
▪ Pipeline Thermal Expansion Analysis
▪ Bottom roughness
▪ Pipeline Installation
▪ Flow Assurance
▪ Shore approach design & River Traffic
38
DNV GL © 2017 15 October 2018
Regulatory Codes & Standards
39
Regulatory
NOM-007-SCRE-2010NOM-001-SECRE- 2009
Transport of Natural Gas (Mexican Standard)Specifications of Natural Gas (Mexican Standard)
American Society of Mechanical Engineers
ASME B31.8 Gas Transmission and Distribution Piping Systems
American Petroleum Institute
API RP 1111Design, Construction, Operation and Maintenance of Offshore Hydrocarbon Pipelines (Limit State Design)
API Spec 5L Specification for Line Pipe
DNV
DNV-OS-F101 Submarine Pipeline Systems
DNV-RP-F103 Recommended Practice for Cathodic Protection of Submarine Pipelines by Galvanic Anodes
DNV-RP-F105 Recommended Practice for Free Spanning Pipelines
ISO
ISO 15589-2Petroleum, petrochemical and natural gas industries – Cathodic protection of pipeline transportation systems – Part 2: Offshore pipelines
DNV GL © 2017 15 October 2018
Code Allowables: API, ASME, DNV
40
DNV
DNV GL © 2017 15 October 2018
Wall Thickness Calculation Check
41
Wall thickness criteria
▪ Burst Design
– ASME B31.8, para. 841.1.1 (same as 49 CFR 192.105)
– API RP 1111, section 4.3.1.1
– DNV OS-F101, pressure containment
▪ Collapse design
– API RP 2RD, Section 5.4, Hydrostatic Collapse
– API RP 1111, Collapse due to External Pressure
– API RP 1111, Buckling due to Combined Bending and External
Pressure
– DNV OS-F101, Collapse due to external pressure, local buckling
DNV GL © 2017 15 October 2018
Pipeline On-bottom Stability
42
▪ Driving Forces
– Inertia forces from the waves
– Drag Forces from wave and current
▪ Resisting or Restoring Forces
– Soil interaction and friction
– Passive resistance due to penetration
DNV GL © 2017 15 October 2018
Research Philosophies
43
▪ American Gas Association A.G.A program
– Hydrodynamic tests performed at DHI in Denmark, key authors
V. Jacobsen et.al
– AGA software that determines stability of pipeline based the
ability of pipeline to resist movement from a given storm build-
up
▪ DNV-RP-F109
– PIPESTAB, Esso Norge, Statoil & SINTEF, key authors R Verley
et.al
– DNV GL Stablelines, PONDUS
– Determines pipeline resistance based on absolute (no pipeline
movement) and generalized stability (allowing certain
displacement e.g. L = 5* D or 10 D)
DNV GL © 2017 15 October 2018
Soil resistance
44
▪ Sand
– Small dependency on density (except for sand with high
calcium carbonate)
– Lower bound coefficient of friction = 0.6
▪ Clay
– Strong dependency on density and shear strength,
su ranges from 500 Pa (thick black water) to 70,000 PA (stiff
Teflon)
– Lower bound coefficient of friction = 0.2
DNV GL © 2017 15 October 2018
Lateral Stability – How to obtain stable pipe
45
▪ Steel weight, higher WT increases the weight
– rsteel = 7950 kg/m3
– But adds to cost
▪ Concrete coating, used to increase weight
– Density: 1900-3400 kg/m3 but
– Increases diameter (and loads) 40 -120 mm
▪ Partially or fully bury the pipe
▪ Trenching
▪ Restrain the pipe e.g. using piles or rock berns
– Be aware of overloading (moment/strain) & fatigue
DNV GL © 2017 15 October 2018
Pipeline Fatigue
46
• Strong tidal and bottom current
• Seabed conditions are very dynamic
• Scouring produces span gaps of less
than a foot
• DNV RP F105 provides guidance for
allowable span lengths to mitigate
VIV
DNV GL © 2017 15 October 2018
Allowable Free Span Length
▪ Allowable span length calculation is based on DNV RP
F105
▪ Allowable span length criteria:
– Screen fatigue;
– Fatigue
– Response model (VIV inline and cross flow)
– Force model (wave induced fatigue)
– ULS (strength, local buckling)
47
▪ The designer’s calculation results were assessed with DNV software – FatFree, and
the results showed reasonable comparison.
DNV GL © 2017 15 October 2018
Soil Springs
▪ Soil springs maybe developed using the following methods
– Clay: American Lifeline Alliance (ALA 7/2001);
– Sand: DNV RP F105, DNV RP F109, DNV RP F110;
– Large Displacement: R. Verley, ASME-OMAE 1995;
▪ Vertical: linear or non-linear springs can be used in analysis
▪ Axial and Lateral: Effective frictions are generally developed based
on submerged weight of the pipe under different conditions, as one
of the contact properties in FE model;
48
DNV GL © 2017 15 October 2018
Bottom Roughness
▪ Bottom roughness analysis (FEA) is carried out to serve the
following purpose:
– Identify free spans under different phase (location and
length);
– Identify high stresses in the pipeline due to bottom
roughness;
– Check if there is any global buckling issues;
▪ Finite Element models reflects:
– Pipe structure and submerged weight;
– Realistic material curve
– Seabed roughness;
– Pipe-soil contact (vertical stiffness, axial and lateral frictions);
– Pipeline conditions (as-laid, flooded, hydrotest, and operation)
with pressure and temperature profile;
49
DNV GL © 2017 15 October 2018
Thermal Expansion
50
▪ Pipeline Expansion
– Temperature: temperature differential with
as-laid condition;
– Pressure
– End cap effect due to pressure differential
(position);
– Poisson effect due to pressure differential
(negative);
▪ Pipeline expansion analysis was considered
with:
– FE method (non-linear soil friction, global
buckling, seabed roughness etc. can be
considered, more accurate);
– Subsea Tie-ins
DNV GL © 2017 15 October 2018
Pipeline Installation
DNV GL © 2017 15 October 2018
Pipeline Flow Assurance (FA)
▪ Flow Assurance shall consider the following parameters
– Pipeline elevation profile
– Hydrate management strategy
– Gas composition, temperature & pressure conditions for steady state and transient
conditions
– FA to support commissioning, N2 displacement, initial startup conditions
▪ Steady state and Transient FA calculations typically use OLGA & PipeSim
software programs
52
DNV GL © 2017 15 October 2018
The appropriate method shall meet technical
and environmental issues beyond the
management aspects of costs and schedules.
• Severe environmental conditions.
• High dynamic and interaction between
waves, currents and sediment
transportation.
• Site investigation, installation design
and operation difficulties.
• Pipeline on-bottom stability throughout
the design life, concrete coating.
• Environmental issues and regulations,
buried pipeline, etc.
Near Shore challenges
DNV GL © 2017 15 October 2018
Pipeline other Design Issues
▪ Cathodic Protection & Internal Corrosion
▪ Inspection, Repair & Maintenance
▪ Integrity Management
54
DNV GL © 2017 15 October 2018
SAFER, SMARTER, GREENER
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Questions
55