Artic Pipeline Transport

8/6/2019 Artic Pipeline Transport

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SnamprogettiOctober 19th, 2005

THE UNIVERSITY CENTRE IN SVALBARD (UNIS)COURSE IN ARCTIC ENGINEERING

AT-327 ARCTIC OFFSHORE ENGINEERING

OCTOBER 19, 2005

ARCTIC PIPELINE TRANSPORT

OF HYDROCARBONS

Luigino VITALISnamprogetti S.p.A.

Via Toniolo 1, 61032, Fano (PU), [email protected]


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Snamprogetti 2October 19th, 2005

PROJECT DEVELOPMENT SCENARIO GAS TO MARKET

OFFSHORE PIPELINE TECHNOLOGY

PIPELINE SYSTEM DESIGN PHILOSOPHY

DESIGN PROCESS PIPELINE INSPECTION AND MAINTENANCE

LIMIT STATES BASED DESIGN

EXERCISES

OUTLINEOUTLINE


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NET GAS FLOW TRADE

Ugo Romano (EniTecnologie)

NATURAL GAS: FROM RESERVES TO MARKET.

Conference Gas Naturale una Fonte Affidabile e Versatile -EniTecnologie - San Donato Milanese 14 Dicembre 2004

Net Gas Flow (bcm): TODAY

Net Gas Flow (bcm): 2030


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GAS-TO-MARKET: POTENTIAL GAS IMPORT TO EU15 (EU30)

Source:FUTURE NATURAL GAS SUPPLY OPTIONS AND SUPPLY COSTS FOR EUROPE, OME 2001

ALGERIALYBIA

EGYPT

TRINIDAD

RUSSIA

NORWAY

1

55(60) 1

73 (130)

50

5

82

(90) 11 12

113 (200)

(100)90

1

35 25

113 (200)

105(115)

10

1520

NIGERIA

(120)110

2000

2010

2020

ALGERIALYBIA

EGYPT

TRINIDAD

RUSSIA

NORWAY

1

55(60) 1

73 (130)

50

5

82

(90) 11 12

113 (200)

(100)90

1

35 25

113 (200)

105(115)

10

1520

NIGERIA

(120)110

2000

2010

2020

0

150

300

450

600

1 2 31999 2010 2020

GSm3

Gas Demand Forecast 20102020 - UE-15Source: OME 2001

Power

Industry

Residential & Commercial

0

150

300

450

600

1 2 31999 2010 2020

GSm3


0

150

300

450

600

1 2 31999 2010 2020

GSm3

0

150

300

450

600

1 2 31999 2010 2020

GSm3


Power

Industry

Residential & Commercial


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Distance, km

0 500040001000 2000 3000 6000

AC/DC Wire

PIPELINE

GAS to LIQUIDS:Syndiesel, DME, Methanol

LD.HC.HP.HGPipelines

GasVolum

e,BCM/year

25

15

10

5

0

20

30

LNG

GAS TO MARKET OPTIONSGAS TO MARKET OPTIONS


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CROSS-COUNTRY PIPELINES:CURRENT AND NEAR-TO-COME R & D OUTCOME

(Transportation cost less than 1.5 $ / MBTU)

Long Distances (LD.): 3000 7000 km

High Capacities (HC.): 15 30 Gsm3/y

High Pressures (HP.): 10.0 15.0 MPa

High Grades (HG.): X80 X120 API 5L

TECHNOLOGY INNOVATION:

A UNIQUE WAY TO COST REDUCTION ANDIMPROVED RELIABILITY


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2.000DISTANCE, km

4.000 6.0000 8.000

$/MBTU

1

2

0

3

TRANSPORTATION

WELL HEAD

TRANSIT FEES

BORDER LINE COST IN EU (2nd HALF NINTIES)

LP Land Pipelines LD.HC.HP.HGLand Pipelines

BREAKEVEN

DISTANCE

BREAKEVEN DISTANCE FOR GAS TRANSPORTATION VIA PIPELINE


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GAS TO MARKET OPTIONSThe key solutions of gas transport as a function of Volumes and distancies

LNG PIPELINELNG PIPELINE

SUPPLY COST FOR GAS DELIVERY TO EU15 (2010-2020)Source: Future natural gas supply options and supply costs for europe, OME 2001


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GAS TO MARKET OPTIONS

LNG and Onshore/Offhore Pipeline Systems are the twopossible alternatives from the economical and technicalpoint of view

Transportation cost of unit of energy increases due toharsh and remote environment to be crossed

Advanced engineering and technology is required forconstruction and operation

AND EXPORT FROM ARCTIC REGIONS?


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56 GAS PIPELINERUSSIA - CHINA - JAPANWestern Siberia - Shanghai

BOLSHEKHETSKAYA

SHANGHAI

Ob

skaya

Gub

a

Western Siberia

Russian section 2700 kmRussian section 2700 km

Chinese section 3900 kmChinese section 3900 km

56 GAS PIPELINERUSSIA - CHINA - JAPANWestern Siberia - Shanghai

BOLSHEKHETSKAYA

SHANGHAI

Ob

skaya

Gub

a

Western Siberia

Russian section 2700 kmRussian section 2700 km

Chinese section 3900 kmChinese section 3900 km

0

500

1000

1500

2000

2500

3000

0 1000 2000 3000 4000 5000 6000 7000

P_km

A relevant example:

STUDY ON LD.HC.HP.HG. GASPIPELINE FROM NORTH-EAST

RUSSIA TO CHINA

Permafrost

Bottom roughness

Seismic activity Slope stability

Hydro-geo hazards

POTENTIAL PROJECT SCENARIO:LD.HC.HP.HG. GAS PIPELINES CROSSING HOSTILE ENVIRONMENT


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Investment andoperating costs for

HP (advancedX100), 6600 kmpipeline for 30109Sm3/y.

78,9

5,8

9,26,1

Invest.+ Oper. Costs 14152 106

Operating Costs 1433 10

6

ATCI 0,0600 /m3

HP 56 inch Single Pipeline X 100 (fuel 0,075 $/m3)

%

%%

%

Pipeline Investment

Station Investment

Fuel

Other Operating Costs

Pipeline Investment

Station Investment

Fuel

Other Operating Costs

LD.HC.HP.HG. GAS PIPELINE FROM NORTH-EAST RUSSIA TO CHINA:A COMPETITIVE OPTION FOR GAS-TO-MARKET


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Location of proposed Mackenzie Valley Gas Pipeline

30 ND 1200 km

NEW ARCTIC PIPELINES


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Location of proposed AlaskaHighway Pipeline

42 ND - 2810 km e 140 bar



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Poronaysk

Nogliki

Piltun

Okha

Nikolayevsk -na-Amure

Aleksandrovsk -Sakhalinskiy

Yuzhno -Sakhalinsk

Sakhalin

Island

Russia

Katangli

DeKastri NyshDetail 2

Detail 1

Boatasyn

Gas Compression(BS#2)

172 km Piltunshoreline toOPF

636 km48 Gas Line

Oil Booster(BS#2)

636 km24 Oil Line

Detail 3

Sakhalin Phase II Development ProjectOnshore Pipelines Project

The development includes :

- 20 OD oil and 20 OD gas pipelines from PiltunShoreline-Tie in Point, through a route about 172 km long,to OPF. Booster Compression Station in proximity of theLandfall of Lunskoje pipelines;

- 24 OD oil and 48 OD pipelines from OPF,through a route about 636 km long, to LNG plantand Oil Export Terminal.

The scope of work includes:

- Development of fault crossing routing, alternative crossingconcepts, and design assessment alternatives

- Basic design including strength capacity assessment,pipeline response analysis, selection and qualification ofcrossing concepts

- Detailed design of 24 fault crossing



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Detail 1

20 Gas Line

20 Oil Line

41 km PA-B to shore

17.5 km PA-A to shore

41 kmshore toBoatasyn

Boatas

PA-

B

PA-A

14 Oil Line

14 Gas Line

Onshore Tie -in pointwith pig traps for allpipelines

20 Oil

172 kmPiltun

shorelinetoOPF

Detail 2

4.5 glycolreturn

LUN-

A

FuturepipelineOPF

Booster /Compression Station

No.1 (BS#1)

30 multiphase30 multiphase

20 Gas line

24 Oil

48Gas

13.5 km LUN -A to shore7.5 km shore to OPF

LNGTanker Non ice strengthened

2 ice breakersupport vessels

LNGPlant Oil Export

Terminal

36Loading

Line

5.5km

Tanker ofOpportunity

Domestic SupplyOff-Take

Detail 3

24 Oil & Condensate Line

48Gas Line

636 km OPFto OET

Sakhalin Phase II Development ProjectOffshore Pipeline & Cables project

The SAKHALIN II Project is a development ofOffshore oil and gas field on the north-eastern shelf of Sakhalin Island,Russia. There are two production fields associated with the project.Piltun-Astokhshoye (PA) is an oil field with associated gas and Lunskoye(LUN) is a gas field with associated condensate.

The offshore pipeline system includes:Piltun Location 14-inch ND x 17.5 km Gas Pipeline Expansion Spool, J-Tube

pull-in from the existing PA-A platform to shore 14-inch ND x 17.5 km Oil Pipeline, Expansion Spool, & J-Tube

pull-in from the existing PA-A platform to shore 14-inch ND x 41 km Gas Pipeline & Expansion Spool from PA-

B to shore

14-inch ND x 41 km Oil Pipeline & Expansion Spool from PA-Bto shore

Lunskoye Location 2 x 30-inch ND x 13.5 km Multiphase Pipelines & ExpansionSpools from LUN-A to shore 1 x 4.5-inch x 13.5 km MEG from the OPF landfall to LUN-A Two power / telecom cables x 13.5 km from the OPF landfall

to LUN-A including J-tube pull-in

Aniva Bay Location 1 x 30-inch x 5 km Oil Export Pipeline from the OET landfall to

the TLU 1 x 10-inch x 1 Outfall Pipeline from the OET One power / telecom cable from the OET landfall to the TLU,

including J-Tube pull-in



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EXERCISES

OUTLINEOUTLINE


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( Shallow to Ultra-deep water trunklines for international gas network.

Trunklines (rigid steel), long (~ 102 km) and generally large diameter(> 16 OD), transporting hydrocarbons mostly sweet gas at highpressure (> 10 MPa).

( Inter-field (special) pipelines /flowlines for shallow to ultra-deep

waters offshore production systems.Interfield (rigid or flexible) pipelines (flowlines), short (~ 101 km) andin general small diameter (< 16 OD) pipelines transporting single ormultiphase often untreated and sour hydrocarbons.


PROJECT DEVELOPMENT SCENARIO


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KEY ISSUES FOR DEEP WATERS TRUNKLINES

Materials & Line Pipe Technology

Installation Vessels & Equipment

OFFSHORE PIPELINES: THE NEW CHALLENGES


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DEEP WATER FIELD DEVELOPMENT

IncludingIncluding: Drilling and completion systems

Surface and subsea structures

Floating and subsea production systems

andand RISERS, FLOWLINES, AND EXPORT PIPELINES

(SPECIAL e. g. insulated, C.R.A., P.I.P., etc.)



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Deep Waters vs. Shallow to Medium Waters

Technical Challenges

DESIGN - thick line pipe, high grade steel

- reliability-based design criteria

- survey

CONSTRUCTION - lay equipment

- intervention work technology

OPERATION - inspection, maintenance

- repair

Technical FeasibilityBottom roughness, geo-hazards, lay-ability, pipeline integrity criteria



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2) GREEN STREAM PIPELINE

KP0 KP100 KP200 KP300 KP400 KP500 KP600 KP700 KP800 KP900 KP1000 KP1100 KP1200 KP1300

-3000-2500-2000-1500-1000

-5000

-3000-2500-2000-1500-1000-5000

200000 E 400000 E 600000 E 800000 E 1000000 E 1200000 E

2400000N

2600000N

2800

000N

2400000N

2600000N

2800

000N

-4000

-3500

-3000

-2500

-2000

-1500

-1000

-500

0 m500 m

1000

4) IRAN to INDIA PIPELINE

3) ALGERIA to SPAIN PIPELINE

Tuapse

Izobilnoye

Tuapse

Izobilnoye

1) BLUE STREAM Pipeline


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traditional and challenging offshore pipeline projects;(ultra-deep, harsh environments, bottom roughness,geo hazards, severe service conditions etc)

frontier areas pipeline projects;(arctic and sub-arctic, severe seismic environments etc)

CURRENT PIPELINE SYSTEMS PROJECTSCURRENT PIPELINE SYSTEMS PROJECTS


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Harsh Environments Ice gouging in the shallow water areas ( < 25 - 30 m ) Severe seismic environment

Rationalization of pipeline system design philosophy

Limit state based design to optimise offshore pipeline systemfrom the technical and economical point of view in relation tohazards

Advanced technology for design, line pipe fabrication,

construction and Inspection/Monitoring and Repair

DESIGN ISSUES FOR OFFSHORE PIPELINES IN ARCTIC ENVIRONMENTDESIGN ISSUES FOR OFFSHORE PIPELINES IN ARCTIC ENVIRONMENT


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OUTLINEOUTLINE






EXERCISES


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Designer must guarantee the compliance of the whole systemwith the safety targets and standards, with design

responsibilities in charge to other functions

IDENTIFICATION OF CRITERIA AND PHILOSOPHIES

(with reference to rules, standards, contractual requirements)

HSE PlanHSE Plan

DEVELOPMENT SAFETY ANALYSES AND REVIEWS

HAZARD IDENTIFICATIONHAZARD IDENTIFICATION

HSE REVIEWSHSE REVIEWS

ProceduresProcedures WHAT / IF ANALYSISWHAT / IF ANALYSIS

EVALUATION OF RESIDUAL RISKCOMPARISON WITH ESTABLISHED CRITERIA

QUANTITATIVE RISK ANALYSISQUANTITATIVE RISK ANALYSIS

REQUIREMENTS FORREQUIREMENTS FOR

INSPECTION ANDINSPECTION ANDMAINTENANCEMAINTENANCE

Pipeline System Design Philosophy


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92148Fittings

3139Flexible lines

65209Steel lines

No. of Incidents Resultingin a Loss of Containment

No. of Incidentsto Operating Pipelines

N/AN/A1SPM (single point mooring)

9,3x10-5289 52227Mid Line (outside Platformor Well Safety Zone)

2.3x10-32 5866Within Subsea Well Safety Zone

1.1x10-31677618Within Platform Safety Zone

7.2x10-41677612Riser

N/AN/A1Platform

Leak Frequency(km-year)

Operating Experience(km-years)

No. of Incidents Resultingin a Loss of Containment

20 %9 %14 %57 %

Rupture> 80 mm20 - 80 mm< 20 mm

Equivalent hole diameter (mm)

INCIDENTS TO OPERATING LINES

LEAK FREQUENCY FOR OPERATING STEEL LINES

EQUIVALENT HOLE SIZE DISTRIBUTIONS FOR OPERATING STEEL LINES

P

A

RLOC

2

001


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ANALYSES OF 30 YEARS OF INCIDENT DATA

- European Gas Pipeline Data Group

- Western European Cross-Country Pipeline

- US Department of Tranportation, Office of Pipeline Safety, Research and SpecialProgram Administration

show US and European pipelines becoming safer.

Gas pipeline annual failure rate from 0.81.5 to 0.150.21 x 10-3/ km-year

Oil pipeline annual failure rate from 1.21.8 to 0.300.60 x 10-3/ km-year

SATISFACTORY PERFORMANCE


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PIPELINE SAFETY DESIGN PHILOSOPHYin accordance with DNV OS-F101, 2000

Fluid Classification Location Class Definition

Serviceability vs. Ultimate Limit States

Safety Class Approach

Safety Targets from Industry Standards,

Failure Statistics and Current Design Criteria vs. Performance.

PIPELINE SAFETY DESIGN PHILOSOPHY


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FLUID CLASSIFICATION


Gases or liquids, not specifically identified in table, shall beclassified in the category containing substances most similar inhazard potential to those quoted. If the fluid category is not clear,the most hazardous category shall be assumed.

E


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LOCATION CLASS DEFINITION

PIPELINE SAFETY DESIGN PHILOSOPHYin accordance WITH DNV OS-F101, 2000


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SAFETY CLASS APPROACH


Safety Class LOW where failure implies low risks of humaninjury and minor environmental and

economic consequences.

Safety Class NORMAL for conditions where failure implies riskof human injury, significant

environmental pollution or very higheconomic consequences.

Safety Class HIGH for conditions where failure implies highrisk of human injury, significantenvironmental pollution or very higheconomic consequences.


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IDENTIFICATION OF SAFETY CLASSES


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TARGET SAFETY LEVELS



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IMR

The ideal safety path


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PIPELINE SYSTEM DESIGN PHILOSOPHYfrom prescriptive to goal settings design

Hazard Identification

The HAZID Analysis shall be carried out by the Project designspecialists in order to:

identify novel or unforeseen sources of hazard;

verify that the hazards and causes are credible;

confirm controls already adopted by the Project;

comment on Occurrence and Severity ratings;

reply to recommendations put forward during the study.


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PIPELINE SYSTEM DESIGN PHILOSOPHYfrom prescriptive to goal settings design

design loads identification

Design Standard Application

Hazard Identification

Residual Risks Evaluation

Residual Risks Comparisonwith Project Acceptance Criteria

Acceptable?

Project Design

Incorporate

Risk Reduction Measures

Yes

No

Environmental Loads

Accidental Loads

Construction Loads

Other Loads

HSE Objective

Operational Loads

SafetyStudies

Design Standards

Accidental Loads

Anchoring

Fishing Activities

Environmental Loads (Freq


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OFFHSORE PIPELINE SAFETY

A worldwide attention to sustainable risk in a context of increasinglycongestioned/interfering-with-human-activities pipeline system for gathering andtransportation of hydrocarbons;

The ageing of important offshore pipeline systems calling for increased inspectionand, sometimes, rehabilitation with new operational strategies beyond thoseenvisaged at the design stage;

A general interest in developing International Standards and design guidelines

reflecting current pipeline technology and complying with quantitative safetytargets.

Show that the performance of modern pipeline systems, built during the last two

decades and designed in compliance with design formats and criteria in forcesince the Sixties, over 30 years of operation is satisfactory: 10-3 10-4 misfit /

year-km.

Market growing, strategical services security of supply need high performances.

Can we do better or at least the same for Arctic and Sub-arctic Pipelines?

Performance studies based on both failure statistics and analytical approachesmotivated by:


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DESIGN PROCESS

PIPELINE INSPECTION AND MAINTENANCE


EXERCISES

OUTLINEOUTLINE

FIELDS OF APPLICATION


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from exploration through production to export

FIELDS OF APPLICATION

Pi li D i ltidi i li h


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Pipeline Design: a multidisciplinary approach


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ONON--SHORE PIPELINE DESIGNSHORE PIPELINE DESIGN

PIPELINE ROUTE

SELECTION AND STUDIESBASIC AND DETAILED

DESIGNENGINEERING DURING

CONSTRUCTION

DATA COLLECTION, FIELDINVESTIGATIONS AND TESTS

SIZING OF LINE PIPES DESIGN OF PIPELINES AND

RELATED CIVIL AND

MECHANICAL WORKS DOCUMENTS AND REPORTS

FOR PERMITS ANDAUTHORIZATIONS

DOCUMENTS FORCONSTRUCTION CONTRACTS

DESIGN OF SPECIAL SECTIONS MATERIAL LIST AND

SPECIFICATIONS

DESIGN FOR SPECIFICSITE CONDITIONS

ASSISTANCE DURINGCONSTRUCTION

LAND RESTORATION

WORKS AS-BUILT DRAWINGS

PIPELINE CORRIDORDEFINITION

ROUTE SURVEYS ANALYSIS OF TECHNICAL

AND PHYSICAL CONSTRAINTS

(CODES AND LAWS,HYDROGEOLOGY, SEISMICRISKS, MASTER PLANS,PROTECTED AREAS,ARCHAEOLOGICAL AREAS)

ENVIRONMENTAL IMPACTEVALUATION

LAND RESTORATION


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ONON--SHORE PIPELINE DESIGN IN ARCTIC ENVIRONMENTSHORE PIPELINE DESIGN IN ARCTIC ENVIRONMENT

Pipeline design shall be assessed in relation to the permafrostrelated hazards, envisaged along the onshore pipeline routed,particularly:

Permafrost condition and relevant phenomena (thermo-karsts etc.)site specific

Seasonal variation at soil surface and impact on pipeline supportand/or trench solution

Pipeline response analysis under environmental conditions

Strength and Deformation Capacity vs. Ordinary and Extreme Loadsaiming to define steel grade and material requirements in relation tolongitudinal deformability


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ONON--SHORE PIPELINE DESIGN IN ARCTIC ENVIRONMENTSHORE PIPELINE DESIGN IN ARCTIC ENVIRONMENT

Pipeline design of a gas pipeline in the Arctic and Sub-arcticEnvironment can be pursued by an aboveground or underground

solution, particularly:

The aboveground solution offers the following advantages:preserving the tundra upper cover, the possibility to create reliable

construction design, the accessibility for inspection and control.Different types of aboveground pipeline solutions are utilized, atpresent the pile supported pipelines are typical.

As regards the underground solution, the reliable operation ofunderground gas pipelines is limited to engineering solutionsmeeting real conditions and factors affecting the area.


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PIPELINE ROUTESELECTION

ROUTE SURVEYS AND

DATA EVALUATION LINE PIPE SIZING

MATERIALS ANDCOATING SELECTION

TECHNICALDEVELOPMENTS

ENVIRONMENTAL

IMPACT EVALUATION

STRESS ANALYSIS ONIRREGULAR SEABEDS

FREE-SPAN DYNAMIC

ANALYSIS LAYING ANALYSIS

STABILITY & SCOURINGANALYSIS

OVERWEIGHTING &TRENCHING

INTERVENTION WORKS

PIPELINE PROTECTION

CROSSINGS & TIE-INS

DOCUMENTATION FORCONSTRUCTIONCONTRACTS

ASSISTANCE DURINGCONSTRUCTION

AS-BUILT

VERIFICATIONS

AS-BUILT DRAWINGS

ASSISTANCE DURINGIN-SERVICEINSPECTIONS

IN-SERVICECONDITIONEVALUATIONS

REPAIRASSESSMENTS

UPGRADINGANALYSES

OFFSHORE PIPELINE DESIGN

FEASIBILITY STUDY

&BASIC DESIGN

ENGINEERING

DURINGCONSTRUCTION

ENGINEERING

DURINGOPERATION

DETAILEDDESIGN

OFFSHORE PIPELINE DESIGN IN ARCTIC ENVIRONMENTSOFFSHORE PIPELINE DESIGN IN ARCTIC ENVIRONMENTS


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Pipeline burial requirements shall be optimized in relation to the iceberggouging hazards, envisaged along the offshore pipeline route, particularly:

Strength Capacity vs. Ordinary and Extreme Loads

Pipe Sectional Capacity under Increasing Bending Deformations Resistance of Girth and Longitudinal Welds by Engineering

Criticality Assessment

Pipe Sectional Capacity to withstand Soil Vertical Pressure

Pipeline-Ice Keel Protection Requirements Ice-soil Interaction analysis aiming to define:

Soil pressure against pipe wall as a function of depth in thesoil;

Soil deformation during ice keel-soil interaction; Analysis of the pipeline response when subject to ice gouging.

Pipeline Design Process: A Multi-Disciplinary Approach


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PIPELINE SIZING AND FLOW

DATA GATHERINGAND PROCESSING

MATERIAL AND STEEL GRADEOPERATIONAL DATA

ENVIRONMENTAL DATA

OTHER DESIGN DATA

SURVEY DATA

WALL THICKNESS DESIGN

DESIGN BUCKLE ARRESTORS BUCKLING CHECK

DESIGN WEIGHT COATING

SELECT PRELINARYCORROSION COATING

EVALUATE HAZARDS FISHING ETC.

PIPELINE STABILITY DESIGN

PIPELINE SPAN EVALUATION

FINALISE CORROSION COA T

THERMAL ANALYSIS

RISK ANALYSIS

PIPELINE LAYABILITYAND LOCAL BUCKLING

IS LINELAYABLE

EVALUATE OTHERPROTECTION NEEDS

IS LINESAFE

DESIGN ADDITIONALSTABILISATION

TRENCH LINEFOR 100 YEAR CASE

PREPARE ALL

SPECS/DRGSPROCUR./TENDER DOCS

C.P. DESIGN/ANODES

EXPANSION LOOP DESIGN

VALVE STATION DESIGN

SHORE APPROACH DESIGN

STABILITY/PROTECTIONBY WEIGHT

COATING IS SUITABLE

NO

YES

YES

NOT FOR

100 YEAR CASE1/5 YEAR

CASE

IS WALLSUITABLE

NO WALLINCREASE

YES

YES

NO

IS TRENCHINGACCEPTABLE

NO

NO

YES

YES

PIPELINE DESIGN

NO

Hazard due to Surface Waves: Pipeline On-bottom Stability


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Horizontal and vertical stability are keypoints for the offshore pipeline systems;

Different procedures in accordance withinternationally reconnaised code ofpractice are available (AGA, DnV RP E

305); Analysis capabilities include:

Quasi static; i.e. simplified approachthat simulates the effects of externaldynamic actions with static equilibriumequations;

Full dynamic; i.e. complete simulationof the effects of a external actionincluding dynamic effects due to thewave cinematic, pipeline mass, etc.

Bi-dimensional models i.e. detailedinvestigations for special section ofthe pipeline with specific lateralconstraints ( e.g. crossings, subseastructures, trench slope).

Hazard due to Surface Waves: Pipeline On bottom Stability

Shallow water scenarios in arctic environments

i.e. Sakhalin Island, North Canada etc.

Geo-morpho Hazardeous Environments


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Troll Oil Pipeline: The deep depression inTroll Oil Pipeline: The deep depression in FensfjordenFensfjorden

Pipeline crossing uneven seabottom in the arcticenvironment such as, for example, the Barents Sea.

G h d d t I t f th T bidit C t


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Geo-hazard due to Impact of the Turbidity Currenton the Pipeline

Troll Oil Pipeline: Pipeline route approaching the steepTroll Oil Pipeline: Pipeline route approaching the steep

wall and the bore hole exitwall and the bore hole exit

Deflected shape of a pipelineDeflected shape of a pipelineimpacted by turbidity currentsimpacted by turbidity currents

Pipeline laid on an unstable area in the arctic environmentsuch as, for example, the Barents Sea.

Hazard due to Seismic Excitation


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When the pipeline in operationpresents a sequence of suspendedlengths alternating betweencontacts with the seabed orartificial features, the assessmentof the structural integrity of thepipeline under severe groundmotions due to earthquakes,

should account for cyclic bendingstresses which might exceedenvironmental design criteria.

0.00

10.00

20.00

30.00

40.00

50.00

60.00

223600 223700 223800 223900 224000 224100

SeismicStressRespon

se(MPa)

-190

-180

-170

-160

-150

-140

-130

223600. 223700. 223800. 223900. 224000. 224100.K. P.

Depth[m]

on Free Spanning Pipelines

Shallow water scenarios in arctic

environments i.e. Sakhalin Island,North Canada etc..

Hazards due to Sand Wave Mobility


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Sandwaves are mobile bedforms found in

strong tidal current regimes and moderatewave environments.

Prediction of the sandwaves mobility during

the pipeline lifetime is required to preventand avoid unacceptable pipeline-seabed

configurations.

ACTIVITIES Hydrodynamic modelling Sediment transport modelling Sandwave mobility modelling Simulation of pipeline response

to a migrating wave pattern

Pipeline Behaviour during Sand Wave Migration

Shallow water scenarios in arctic environmentsi.e. Sakhalin Island, North Canada etc.

Hazards due to Sea Bed Mobility in the Near Shore Areas


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Pipe burial depth in the shore approachis strongly dependent on the expectedcoastal evolution. Specific studies arecarried out, based on historical data

(topographic surveys, satellite dataetc.) and numerical models, to forecast

the potential seabed and coastlineevolution. Short term and long term

modifications induced by normal and

extreme wave and current conditionsare simulated and the burial depth

needed to avoid possible exposure ofthe pipe during its life is assessed.

Shallow water scenarios in arctic environmentsi.e. Sakhalin Island, North Canada etc.


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Hazard due to Severe Operating Condition


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-1050

-1025

-1000

-975

-950

16700 16750 16800 16850 16900 16950 17000 17050 17100 17150 17200

KP DISTANCE

WATE

R

DEPTH

(m)

AS-LAID

OPERATING

Combined effects of pressure andtemperature may lead to instability

of the pipeline with consequentlateral or vertical displacement.

Advanced analysis procedures are

necessary to analyze thepossibility of occurrence of thephenomenon and to design therequired mitigation measures.

Analysis aims to characterize as follows: definition of pipeline propensity to in-service buckling definition of propensity to develop the buckle in the lateral or vertical

direction definition of post-buckle configuration in terms of displacements and

stresses 3D Finite element non linear analysis

Izobilnoye

Izobilnoye

BLUE STREAM PIPELINES Hazard due to Severe Operating Condition


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Sea Bottom/Temperature Profile

-1780.0

-1680.0

-1580.0

-1480.0

-1380.0

-1280.0

-1180.0

-1080.0

-980.0

-880.0

-780.0

-680.0

-580.0

-480.0

-380.0

-280.0

-180.0

-80.0

9000 11000 13000 15000 17000 19000 21000 23000 25000 27000 29000

Pipeline X Coordinate (m)

WaterDepth(m)

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

16.0

18.0

20.0

22.0

24.0

26.0

28.0

30.0

32.0

34.0

Diff.Temperature(C)

Pipe OD 610.0 mm

Pipe Wall Thickness 31.8mm (D/t 19.2)

Pipe Submerged W eight (empty) 1.5 kN/m

Pipe Submerged Weight (operating) 1.95 kN/m

Axial - Lateral Friction 0.5 - 0.7

Residual Lay Pull 400 kN

Operating Pressure 25.0 MPa at 0.0 m

Max/Min Diff. Tem perature 30.1/7.9 C

Pipe Temperature Profile during Operation:Thermal Expansion vs. Bottom Roughness

TuapseTuapse

1.0

2.0

3.0

4.0

acement[m]


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-1234

-1229

-1224

-1219

-1214

-1209

-1204

18100 18150 18200 18250 18300

Buckle 3

-1318

-1313

-1308

-1303

-1298

-1293

19100 19150 19200 19250 19300 19350

Buckle 4

-864

-859

-854

-849

-844

-839

-834

-829

13900 13950 14000 14050 14100

Buckle 2

-170

-160

-150

-140

-130

-120

-110

-100

9700 9750 9800 9850 9900 9950

-1727

-1726

-1725

-1724

-1723

-1722

-1721

28300 28350 28400 28450 28500 28550

Buckle 6

-1382

-1380

-1378

-1376

-1374

-1372

-1370

19950 20000 20050 20100 20150 20200

Buckle 5

Buckle 1

Pipeline X Coordinate (m)2D Analysis - Pipeline Vertical Configuration Axial friction 0.5 - Lateral friction 0.7

PipelineZCoordinate(m)

-4.0

-3.0

-2.0

-1.0

0.0

9000 10000 11000 12000 13000 14000 15000 16000 17000 18000 19000 20000 21000 22000 23000 24000 25000 26000 27000 28000 29000

RelativeVerticalDispla

2D Analysis - Pressure

2D Analysis - Temperature

Pipeline X Coordinate (m)2D Analysis - Pipeline Vertical Configuration Axial friction 0.5 - Lateral friction 0.7

-3.0E+6

-2.0E+6

-1.0E+6

0.0E+0

1.0E+6

2.0E+6

3.0E+6

4.0E+6

9000 10000 11000 12000 13000 14000 15000 16000 17000 18000 19000 20000 21000 22000 23000 24000 25000 26000 27000 28000 29000

VerticallBendingSM2(N*m)

Temperature - 2D Response

2D FE Analysisto define how

safely the pipeline

copes with bottom

roughness

Fully 3-dimensional FE Analysis to define where and how the pipeline might

develop upheaval buckling at the most pronounced undulations


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-1425.0

-1400.0

-1375.0

-1350.0

-1325.0

-1300.0

-1275.0

-1250.0

-1225.0

-1200.0

-1175.0

-1150.0

17650 17900 18150 18400 18650 18900 19150 19400 19650 19900 20150 20400 20650

Pipeline X Co-ordinate (m)

Wa

terDepth(m)

-10.0

-5.0

0.0

5.0

10.0

YCo-ordinate(m)

develop upheaval buckling at the most pronounced undulations

Advanced engineering analyses have to be carried to minimize mitigation measuresagainst severe operating conditions in arctic environment

Buried Pipelines subject to Seismic Travelling Waves


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BODY WAVES SURFACE WAVES

(A) P-waves or Compression Waves (B) S-waves or Shear Waves

(C) Rayleigh Waves (D) Love Waves

Waves Types Pipe Configuration Seismic Excitation

Pipeline Response

Permanent Ground Deformation Active Faults


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Strike-slipReverse-slip

Surface earthquake fault

Permanent Ground Deformation Active Faults


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Fault Displacements

-0.5

0.0

0.5

1.0

1.5

-5 0 5 10 15

Perpendicular Distance from Fault Scarp (meters x V)

VerticalFau

ltDisplacement(metersxV)

V

0.2 V

3 V 4 V 1.5 V

V is the vertical displacement

reported from field measurement.

-0.5

0.0

0.5

1.0

1.5

-5 0 5 10 15


FaultNormalDisplacement(metersxV)

V

3 V The fault normal displacement, FN, is defined as a function ofthe vertical displacement, V, reported from field

measurement.

Folding and/or

distributed shear

Fault slip on

main fault

-0.5

0.0

0.5

1.0

1.5

-10 -5 0 5 10


FaultParallelD

isplacement(metersxFP)

2 meters, regardless of

displacement

FP is the displacement parallel to the

fault strike and is independent of the

observed vertical displacement.

FP

Pipeline crossing Active Faults


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Pipeline Responsethrough FE Models

Differential Displacement (m)

AxialStr

ain

(-)

High risk seismic area, see for

example, Sakhalin Island

Hazard due to Ice Gouging


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( ) HDH

n

soil eDHDu

=== 0.1DepthBurialPipe,DepthGougeIce

Ice gouging morphology and pipeline threats from iceIce gouging morphology and pipeline threats from ice

keel gouging soilkeel gouging soil

Hazard due to Ice Gouging


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Iceberg grounding theIceberg grounding the seabottomseabottomThe effect of the gouging ice on apipeline depends on the level ofthe pipeline with respect to thegouge, and on the deformation ofthe soil as the ice cuts the gouge.

Within that field, one candistinguish three zones:

An uppermost zone 1, withinwhich the soil is first carried upinto the mound in front of the ice,

and then sideways into the berm; An intermediate zone 2, in which

the soil is deformed plasticallyunder the mound, but ultimatelycontinues under the ice; and

A lowest zone 3, in which the soilpasses under the ice, but issubject to stresses transmittedfrom zone 2.

Hazard due to Ice Gouging - Development of bending deformation


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Max bending strain vs. soil cover, ice keel gouge depth and soilMax bending strain vs. soil cover, ice keel gouge depth and soil lateral resistancelateral resistance

Pipeline and soil displacementsPipeline and soil displacements

due to ice keel gouging in zone 2due to ice keel gouging in zone 2

2.6 2.7 2.8 2.9 3 3.1 3.2 3.3 3.4 3.51

1.5

2

2.5

3

3.5

4

4.5

5

5.5

6

Gouge Depth = 2.1 m - Qu = 250 kN/m




H (m)

Strain(%

)

Hazard due to Ice GougingStrength capacity assessment using advanced FEM analyses and Tests


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Bending and deformationBending and deformationcapacity of pipes subject tocapacity of pipes subject to

axial force, inner pressureaxial force, inner pressure

and bending,and bending,

Results implemented inResults implemented inDNV OSDNV OS--F101 localF101 local

buckling criterionbuckling criterion

0.500

HOTPIPE 2 - EXPERIMENTAL TESTS - PIPE SPECIMEN NO. 3

BENDING MOMENT VS. CURVATURE RELATIONSHIP

0.00E+00

1.00E+05

2.00E+05

3.00E+05

4.00E+05

5.00E+05

6.00E+05

7.00E+05

8.00E+05

9.00E+05

1.00E+06

1.10E+06

1.20E+06

1.30E+06

0.000 0.050 0.100 0.150 0.200 0.250 0.300 0.350 0.400 0.450AVERAGE CURVATURE (1/m)

BENDINGMOMENT(Nm)

T3 Pipe specimen t = 16.2 mm, , fo =0.0%, SMYS = 480 MPa, Mean D FE Mesh, Mid Section,

T3 Pipe specimen t = 16.2 mm, , fo =0.0%, SMYS = 480 MPa, Mean D FE Mesh, Mid Section, Triggering Force

Specimen 3 - Experimental T est

Pipeline Design in Tundra Areas


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Frost Heave

Thermal Analysis

Pipeline Design in Tundra Areas


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Thermal Analysis

Jun

jul

sep

oct

nov

dec

jan

febmar

apr

may

Jun

aug

4

5

6

7

8

9

10

11

12

13

14

15

Month

MonthlyMeanTemperatureforSleipnerEasington(C)

Pipe line Sector from KP 444 to KP 500 Pipel ine Sector from KP 500 to KP 524 Pipel ine Sector from KP 524 to KP 544 Assumed Temperature Prof ile

WINTER SEASON

MONTHLY MEAN TEMPERATURE

TEMPERATURE PROFILES FORDIFFERENT OPERATING

CONDITIONS

1415

e(C)

Frost Heave Analysis


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The heave is not onlycaused by freezing of thein-situ pore water but alsoby water flow to a freezingfront (segregational heave).

This water flow is inducedby a suction gradient thatdevelops in the frozen soil.

The frost heave after the

development of ice bulb isdependent on the value ofthe segregation potentialSPo.

The segregation potential isin general obtained from

laboratory tests.

0 1 2 3 4 5 6 7 8 9 10 11 1256789

1011

1213

Time (month)

GroundTempe

rature

0 1 2 3 4 5 6 7 8 9 10 11 120

0.1

0.2

0.3

0.4

Pipe Internal Temperature -4C



Time (month)

SegregationalHeave(m)

)()( TgradeSPvtPa

oe =

Pipeline Design in Arctic Environment


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Differential Settlement due Frost Heave

OUTLINEOUTLINE


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OFFSHORE PIPELINE TECHNOLOGY PIPELINE SYSTEM DESIGN PHILOSOPHY

DESIGN PROCESS



EXERCISES

Pipeline Inspection and Maintenance Philosophy


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At the end of the design phase:

Diameter, Thickness and material

Pipeline route Construction technology

Intervention works

-Before construction

-After construction Operating philosophy

-Inspection and monitoring plan

-Damage evaluation

-Pipeline repair

Safety objective met

for all relevant limitstates



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Inspection/Monitoring Requirements

The objective is to define:

HowHow to inspect

WhatWhat (and WhereWhere) to inspect

Emergency proceduresEmergency procedures

&&InterventionIntervention measuresmeasures

WhenWhen to inspect

Based onBased on

HAZID, RiskHAZID, RiskAnalysisAnalysis

and inputs fromand inputs from

designdesign

General CriteriaGeneral Criteria

Based on inspection

results and damageevaluation



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Earthquakes vs.Earthquakes vs.

GeoGeo--hazardshazards

Possible occurring earthquakes may trigger

geo-hazards events that may threaten thepipeline structural integrity. The followinggeo-hazards are of major concern:

mass flows

- fault displacements

- soil slides and slumps- turbidity currents

- Travelling waves are usually less severe thatgeo-hazards

Pipeline geometry & configuration

Internal InspectionInternal Inspection

(IMU,(IMU, CaliperCaliper pig)pig)

Condition of area around PL:

Visual InspectionVisual Inspection

Leak detection:

LDS/SCADA systemLDS/SCADA system



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Arctic Hazards:Arctic Hazards:

The following geo-hazards are of major

concern:Ice gouging

Differential settlement

Erosion at landfallPipeline geometry & configuration

Internal InspectionInternal Inspection

(IMU,(IMU, CaliperCaliper pig)pig)

Condition of area around PL:

Visual InspectionVisual Inspection

Leak detection:

LDS/SCADA systemLDS/SCADA system

Design Philosophy

DFI

Safety & Availability

Pipeline System


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As-laid Configuration

Pre-Commissioning

Misfit? Leak?

Accidental Scenarios &Extreme Environmental

LoadsRFO

As-Built Configuration

Ordinary Inspection

(External)

Continuous Leak

Detection (SCADA)

Inspect?

Misfit?Leak?

STOP

Maintenance & Repair

NO

YES

NO

YES

YES

NO

NO

YES

Survey Data

Survey Data

ExtraordinaryInspection (External

&/or Internal)

p y

Inspection Proceduresvs.

Emergency Response


78/119

Pipeline Monitoring and Maintenance .Structural Integrity Diagnosis before . Repair


79/119


External ROV Survey

Shape of pipe anomaly as predictedby FE Analysis

Shape of pipe anomaly as measuredby Internal Inspection

OUTLINEOUTLINE


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OFFSHORE PIPELINE TECHNOLOGY PIPELINE SYSTEM DESIGN PHILOSOPHY

DESIGN PROCESS



EXERCISES

LIMIT STATE BASED DESIGN


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Snamprogetti October 19th, 2005

Design criteria currently in use are based onDesign criteria currently in use are based onallowable stressesallowable stresses and weakly related to actualand weakly related to actual

failure modes.failure modes.

Limit state designLimit state design adopts functional relationsadopts functional relationsdescribing actual failure modes in a formatdescribing actual failure modes in a format

explicitingexpliciting load and resistance factors and refers to aload and resistance factors and refers to a

rationally based safety philosophy weighting eachrationally based safety philosophy weighting eachdesign issue in relation to type of failure and naturedesign issue in relation to type of failure and nature

of consequences and reflecting quantified safetyof consequences and reflecting quantified safety

targets in relevant partial safety factors.targets in relevant partial safety factors.

LSD in the Offshore/Onshore Pipeline TechnologyDeterministic vs. Reliability Approach


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Reliability

Methods

Deterministic

Approach

Limit State Based

Design (LSBD)

Working Stress

Design (WSD)

Load and ResistanceFactored Design (LRFD)

Probabilistic BasedDesign

LSD in the Offshore/Onshore Pipeline TechnologyReliability Based Limit States Design Pursuing given Safety Target


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LIMIT STATES DESIGN FORMAT

Ld( ,F, C,S) < Rd(SC,m)where:

Ld design load effect function

Rd design resistance function

C condition load factor environmental load factor

F functional load factor

S system safety factor

resistance usage factor

Reliability Index

Standard Deviation

Probability Distributionof Safety Margin

(R-L)

1.E-07

1,.E-06

1.,E-05

1.E-04

1.E-03

1.E-02

1.E-01

1.E+00

0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0

Reliability Index,

ProbabilityofFailure

ProbabilityDistribution Resistance

Distribution, R

LoadDistribution, L

Nominal Load

Nominal Resistance

NominalSafety

Domain

fL>1 fR


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g y y

Limit State g(x) = R - L

Criteria, Decision

Loads, L

Long term

Distr., Risk

Uncertainty fx (x)

Failure Probability

Target Safety

Capacity, R

FEM, Test

Tools

Consequences

( )[ ] ( )

( )

==

0xg

f dxxf0xgPP

Limit States/Failure Modes as per DNV OS-F101


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ULTIMATE LIMIT STATES (ULS):ULTIMATE LIMIT STATES (ULS):

BurstingBursting

CollapseCollapsePropagating BucklingPropagating Buckling

Local Buckling due to Combined LoadingLocal Buckling due to Combined Loading

Fracture/Plastic CollapseFracture/Plastic CollapseRatchetingRatcheting (Accumulation of plastic deformation)(Accumulation of plastic deformation)

SERVICEABILITY LIMIT STATES (SLS):SERVICEABILITY LIMIT STATES (SLS):

OvalizationOvalization Limit due to BendingLimit due to Bending

FATIGUE LIMIT STATES (FLS)FATIGUE LIMIT STATES (FLS)

ACCIDENTAL LIMIT STATES (ALS)ACCIDENTAL LIMIT STATES (ALS)

LSD in the Offshore/Onshore Pipeline TechnologyRelevant Limit States (Loads vs. Failure Mechanisms)


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Internal pressure Bursting Fracture/Plastic collapse of defected long. welds

External pressure Collapse Buckle propagation and/or arrest

Combined loads Local buckling

Fracture/Plastic collapse of defected girth welds

Variable loads Fatigue

Operating loads Global buckling

Ultimate Limit States


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FailureFailure occurs when internal actions are no longer able to equilibrateoccurs when internal actions are no longer able to equilibrateexternal loads and consequentlyexternal loads and consequently deformations are uncontrolled by anydeformations are uncontrolled by any

boundaryboundary

Deformation due to external loads are controlled or imposed byDeformation due to external loads are controlled or imposed byexternal boundariesexternal boundaries andand failurefailure occurs at deformation level which activateoccurs at deformation level which activate

material (ductile tearing, cracking etc.) or shape instabilitiesmaterial (ductile tearing, cracking etc.) or shape instabilities ((ovalizationovalization,,

wrinkling and/or bulging/kinking etc.)wrinkling and/or bulging/kinking etc.)

Ultimate Limit States (ULS)Ultimate Limit States (ULS) for a pipeline entail structural damages whichfor a pipeline entail structural damages which

will give rise to the release of the transported fluid into thewill give rise to the release of the transported fluid into the

externalexternal

environment or the flooding of the line, both in the short and lenvironment or the flooding of the line, both in the short and long termong term

Ultimate Limit States


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Longitudinal failureLongitudinal failure modesmodes may develop in the presence of longitudinalmay develop in the presence of longitudinaldefects which cause the reduction of strength capacity for the cdefects which cause the reduction of strength capacity for the containmentontainment

of internal pressureof internal pressure

Circumferential failure modesCircumferential failure modes are associated with excessive longitudinalare associated with excessive longitudinalstresses and strains caused by external loadsstresses and strains caused by external loads

In relation to geoIn relation to geo--morphomorpho hazard,hazard, circumferential failure modescircumferential failure modes due todue tobending effects are of major concern.bending effects are of major concern.

The most critical condition for theThe most critical condition for the localisationlocalisation of deformation is associatedof deformation is associated

with the development ofwith the development of bending strainsbending strains which may be either unbounded orwhich may be either unbounded or

limited by external boundaries.limited by external boundaries.

Sometimes circumferential (and longitudinal) failure modes are aSometimes circumferential (and longitudinal) failure modes are activated byctivated bythethe localization of deformation in fully restrained conditionslocalization of deformation in fully restrained conditions due to highdue to high

temperature in combination with high pressuretemperature in combination with high pressure

LSD in the Offshore/Onshore Pipeline TechnologyTarget safety level (Pf

T) According to DNV OS-F101


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LSD in the Offshore/Onshore Pipeline TechnologyRelevant Limit States (Failure Statistics)


90/119


Corrosion Outside

Forces

Material

defects

Construction

defects

Other

47.1%

0.0%

23.5%

0.0%

29.4%

0.0%

10.0%

20.0%

30.0%

40.0%

50.0%

60.0%

70.0%

Corrosion Outside

Forces

Material

defects

Construction

defects

Other

Corrosion Outside

Forces

Material

defects

Construction

defects

Other

0.4%

99.2%

0.2% 0.0% 0.2%

0.0%

10.0%

20.0%

30.0%

40.0%

50.0%

60.0%

70.0%

80.0%

90.0%

100.0%

Corrosion Outside

Forces

Material

defects

Construction

defects

Other

Total incident by cause in the

midline zone (Offshore gas

pipelines - Gulf of Mexico

experience before 1980 - OD>20),

Ref./VERITAS, 1980/

Total incident by cause in thesafety zone (Offshore gas pipelines- Gulf of Mexico experience before

1980 - OD>20),Ref./VERITAS, 1980/

LSD in the Offshore/Onshore Pipeline TechnologyReliability Based Load and Resistance Factored Design (LRFD)

dd

LLLLL

RL


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DESIGN CHECK (PfT=10 -3)

0

0.5

1

1.5

2

2.5

3

0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2

Stress: L, R

DensityFunctio

ns:fL(L),fR(R)

Load

Resistance

m; C,A, U

Mean Value

Load

Characteristic

Load/load effect F; E; C Mean ValueResistance

Characteristic

Resistance

SC

Design Value

Load and Resistance

SCm

Cd

CAAAEECFFLCd

RR

LLLLL

=

++==


92/119

LSD in the Offshore/Onshore Pipeline TechnologyLocal Buckling (Combined Loading)


93/119


OVALIZATION BUCKLING-

NO PRESSURE

WRINKLING-

INNER PRESSURE

PLASTIC STRAIN

PLOT

DEFORMEDPLOT

Bending and deformationBending and deformation

LSD in the Offshore/Onshore Pipeline Technology

Local Buckling (Combined Loading)


94/119


Bending and deformationBending and deformationcapacity of pipes subject tocapacity of pipes subject to

axial force, inner pressureaxial force, inner pressure

and bending,and bending,

Results implemented inResults implemented inDNV OSDNV OS--F101 localF101 local

buckling criterionbuckling criterion

0.500

HOTPIPE 2 - EXPERIMENTAL TESTS - PIPE SPECIMEN NO. 3

BENDING MOMENT VS. CURVATURE RELATIONSHIP

0.00E+00

1.00E+05

2.00E+05

3.00E+05

4.00E+05

5.00E+05

6.00E+05

7.00E+05

8.00E+05

9.00E+05

1.00E+06

1.10E+06

1.20E+06

1.30E+06

0.000 0.050 0.100 0.150 0.200 0.250 0.300 0.350 0.400 0.450AVERAGE CURVATURE (1/m)

BENDINGMOMENT(Nm)

T3 Pipe specimen t = 16.2 mm, , fo =0.0%, SMYS = 480 MPa, Mean D FE Mesh, Mid Section,

T3 Pipe specimen t = 16.2 mm, , fo =0.0%, SMYS = 480 MPa, Mean D FE Mesh, Mid Section, Triggering Force

Specimen 3 - Experimental T est

LSD in the Offshore/Onshore Pipeline TechnologyLCC Local Buckling (Combined Loading)

112

d2

dd

2

d

+

+

ppMS


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1)

1bc

d

bc

d

pc

dmsc

pc

dmsc

+

+

p

p

p

p

MS

( )( )

>

=

>


96/119


dAAdEEdFCFD

D

,,,

++=

( )

( )

>

Accidental > Functional > Environmental

Exercise No. 1Calculate the Local buckling deformation capacity

using DCC DNV OS-F101 Design Equationi.e. limit value, functional, accidental and environmental value


113/119


Limit Accidental Functional Environmental-5.00%

-4.50%

-4.00%

-3.50%

-3.00%

-2.50%

-2.00%

-1.50%

-1.00%

-0.50%

0.00%

0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 9.00 10.00

Inner Pressure (MPa)

Minimum

Com

pressiveStrain(%)

Limit

Functional

Environmental

Accidental

INPUT DATA

Exercise No. 2Calculate maximum bending strain on a pipeline

induced by ice keel gouging


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Ice keel gouging depth, D = 2.1 and 2.5 m

Pipe outer diameter, Do = 914.4 mm

Pipe steel wall thickness, t = 26.04 mmOuter diameter to thickness ratio, Do/t = 35.12

Steel Grade = API 5L X60

Minimum Specified Yield Stress, SMYS = 415 MPaSMTS derated factor, fu, Temp = 0 MPa

Inner pressure = 0 MPa

Max soil lateral resistance, q = 250 and 450 kN/m

Pipeline burial depth, H (top of pipe) = 2.5 to 3.5 m

FEM Analysis Results




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Maximum and minimum axial strainsMaximum and minimum axial strains

along the pipeline axis in zone 2along the pipeline axis in zone 2Pipeline global horizontalPipeline global horizontal

displacements in zone 2displacements in zone 2

Simplified Analytical Model




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Simplified analytical modelSimplified analytical modelFEM global analysisFEM global analysis


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Rotational equilibrium gives:




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The rotation at each hinge, , isequal to

The bending strain at each hinge isdistributed on a 2.5 Do pipe length

z

u

=

q

MzMzq

p

p

==

82

4

1 2

( ) ( )z

HDuD

D

D

RadiusM

qHDu o

o

o

bend

bendbend

p

,

5

1

525.22

1

8,2.0 ==

===

RESULTS: Applied bending strain vs. soil cover, ice keel gouge depthand soil lateral resistance



4.50%


119/119


0.00%

0.50%

1.00%

1.50%

2.00%

2.50%

3.00%

3.50%

4.00%

2.5 2.6 2.7 2.8 2.9 3.0 3.1 3.2 3.3 3.4 3.5

Pipeline burial depth (m)

Maximumb

endingstrain(%)

q = 250 kN/m; D = 2.1 m.

q = 450 kN/m; D = 2.1 m.

q = 250 kN/m; D = 2.5 m.

q = 450 kN/m; D = 2.5 m.

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