6 experience with new dnv pipeline codes

MANAGING RISK

Experiences with new DNV pipeline codes

Tommy BjørnsenDet Norske Veritas

Milestones in Offshore/Onshore Pipeline ResearchJapan – Norwegian SeminarTokyo, Japan, 27 May 2003

MANAGING RISK

Content of presentation

• Introduction• Historical perspective• Basis for the new DNV codes• Development of the new codes• Industry feedback• Further development• Summary and conclusions

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DNV Objective

To safeguard life, property and the environment

Foundation established 1864

2

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DNV - Main Industries

ProcessOil & Gas RailShipping Automotive

3

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DNV Pipeline Services• Assisting customers in:

– Selecting optimum technology and solutions

– Qualifying technology (incl. R&D)

– Verifying that technology is correctly applied

• Based on:– An in-house multidiscipline

technology environment– A close collaboration with

research institutions– Knowledge and experience

from all over the world

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The Blue Stream Project

• 2 x 24” pipelines, WT 31.8 mm• Offshore length 390 km• Project challenges:

– Water depth of 2150 m– Sediments with H2S content– Seismic activity– Sediment flow– Difficult topography– The required technological

innovation– Tight schedule– Development of repair

systems

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Pipelines in a historical perspective

• 1000 AC:First known gas pipelines made of bamboo, in Japan

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• First oil pipeline was built for the Nobel brothers in Baku, 1878 – About 10 km and

76 mm diameter– Balakhany fields to

Nobel's refinery in Cherny Gorod

– Decreased transport cost with 95%

– The whole pipeline was paid back in one years time!!

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Pipeline from Baku to the Black Sea in 1905

• 8 inch diameter• 800 km's long

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Historical perspectiveDesign code development

• In the US, the development of a national pressure piping code was discussed as early as 1915

• In March 1926, the American Standards Association initiated project B31

• In 1935 the American Tentative Standard Code for pressure piping, B31, was published

• In 1951, B31.4 & 8 were published

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DNV involvement in Pipelines

Historical perspectiveDesign code development

1900 1950 2000

ASM

E B3

1.4

&B3

1.8

DNV

Rule

s fo

r Sub

mar

ine

Pipe

line

syst

ems

1976

DNV

Rule

s fo

r Sub

mar

ine

Pipe

line

syst

ems

1981

BS 8

010:

3IS

O 1

3623

Allowable stress design

ASM

E B3

1 19

26

Limit state d.

DNV

Offs

hore

Sta

ndar

d F-

101

SUPERB1992-1996

The first limit statebased Pipeline design code with calibrated

safety factors!

DNV

Rule

s fo

r Sub

mar

ine

Pipe

line

syst

ems

1996

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Historical perspectivePremises for the “best” pipeline code

• Which one is the best design code?– The one that gives the thinnest wall?– The one that gives the thickest wall?

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The first requirement of the code is:• Document sufficient safety level

Given the first premises, the second is:• Give the lowest total life-cycle cost

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• What is sufficient safety level?– Traditional design codes have a historical

record accepted by society at large, hence they do provide sufficient safety level for traditional pipeline design in general

– For new applications and for optimisations (concepts, temperatures, pressures, water depths etc.) limit state based design codes are required to ensure consistent safety level

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• Lowest life cycle cost

• Offshore pipelines cost appr. US$ 1000/m

• Cost optimisation

As installed pipeline cost

Installation40 %

Materials30 % Intervention

20 %

Engineering/ Admin

10 %

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Design format - Expressions

• Limit state methodology– Consider each failure mode independent

• Load and Resistance Factor Design (LRFD)– A “deterministic” design criteria with partial

safety factors (One interpretation of the limit state format)

• Structural reliability - probabilistic analyses– Tool to, for a given failure probability, calculate

partial safety factors

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Typical limit states in pipeline design

• Pressure containment• Local buckling

– Collapse– Combined loading– Propagating pressure

• Global buckling– Snaking– Upheaval buckling

• On bottom stability• Trawling interference

• Fatigue due to– Pressure variations– Temperature– Vortex shedding

• Fracture– Fracture propagation

(Content dependent)– ECA

• Ovalisation• Ratcheting

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Collapse and propagating buckling

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Design formatLRFD versus ASD

• ASD– Easy to use– Less checks– (Should) Give(s)

same result as LRFD for ”normal design”

– Includes (implicit) design rule of thumbs

• LRFD– Consistent safety

level– Flexible– Allows optimisation– Less dependent on

assumptions– Can easier be

extended to new scenarios

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SUPERB Project

• ObjectiveDevelopment of a SUbmarine PipelinEReliability Based design guideline and in that respect to review and update design recommendations and criteria for pipeline design

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SUPERB-The Project

Pre-phase Phase 1M Phase 2M Phase 3M• Pilot

studies• Safety

assessment• State of art

Technology

• Technologydevelopment

• Revised Safetyand CalibrationProcedures

• Draft Guideline

• Synthesis• Finalization• Guidelines

US$ 100 k US$ 500 k US$ 500 k US$ 400 k

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SUPERB -Database; Model uncertainty

Property Data points Projects Validity

Burst 76 (22SUPERB)

X52-X1206<D/t<25

Collapse S=0,Seamless, UOE

3500 (39) (6-7) X65-X7016<D/t<45

Collapse+axial 15-20

Collapse+moment 148 X52-X70

MomentSmall pipes

>100(+50 FEM)

X52-

Internal pressure+moment

2 (+100 FEM)

Burst (corroded) >100 (60)(+500 FEM)

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SUPERB -Database; Material (Welded only)

Property Data points Projects Validity

Yield >1000 >20 X60-X80

Ultimate >1000 17 X60-X80

Y/T >100 >5 X60-X80

CTOD 291 100

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New DNV pipeline codes

• DNV’96 was published on the basis of the results from the SUPERB project

• This included:– Limit state based design – Calibrated safety factors– Further benefit to improved material quality

(ductility and yield stress distributions)• DNV’96 was updated and published as

DNV-OS-F101 in 2000• An extensive list of additional documents

supporting the main pipeline standard

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Recommended PracticesDNV-RP

Offshore StandardDNV-OS

Offshore Service Specification

DNV-OSS

DNV Offshore Codes

Quali

ty &S

afety

Stru

ctur

es Systems

Special Facilities

Pipelines & RisersMater

ials T

echn

ology

FA B C D E

Clas

s

Shelf

Com

pl.

Cert.

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DNV Offshore CodesOffshore Standard (OS)

• Technical requirements only

• Harmonised with ISO– ISO 13623 Pipeline

Transportation Systems– ISO 3813-3 Linepipe

• Limit state based design criteria

• Calibrated safety factors

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Under developmentExisting

Residual strength

Corroded pipes(British Gas)

Mechanical Pipeline Couplings

Gudesp(DHI)

Multispan(DHI, Snamprogetti)

Protection(Statoil)

Reeling JIP(Sintef & TWI)

DNV Offshore CodesRecommended Practices (RP)

TrawlingDNV-RP-F10X

Design of HT/HP

Pipelines

DNV-RP-F10XDesign of

HT/HP Pipelines

Hotpipe(Statoil, ShellSnamprogetti)

Design of Titanium Risers

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DNV Offshore Codes DNV-OS-F101 -The World

Blue StreamGazprom/ENI

Two 610 mm diameter pipelines from Russia to Turkey across the Black Sea. Maximum water depth is 2150 meters. Length is 2 x 400 km

Nam Con Son BP Amoco

A 360 km, 32” submarine pipeline from the offshore field complex to

the onshore gas terminal.

West Natuna Pipeline Project Conoco

A 600 km, 28” submarine pipeline from the offshore field complex in Indonesian waters to the onshore

gas terminal in Singapore.

Zakum Gas Injection Project Adma-Opco

Two high pressure gas injection pipelines for the Zakum field. This was the first project that applied the DNV’96 in the Middle East.

Tangguh Field Development Arco

Situated in the "Bird’s Head" area of West IrianJaya,. The Upstream platform facilities are

approximately 25km km apart with conventional platforms and gas being exported by submarine

pipelines, 20km to 30km in length, to the Onshore Receiving Facility (ORF). The gas has a relatively high CO2 and H2S content and includes free water.

Mardi Gras Pipeline transportation system (BP)Several fields including Crazy Horse (6300ft)MMS approved use of DNV-OS-F101 for this

project

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DNV Offshore CodesReception from the industry

“Comparing DNV’96 to traditional pipeline design is

like comparing a modern computer to a computer from

the 1980ies...”

Prof. A. Palmer OPT Conference 25-26 Feb. 1999 Amsterdam

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Upstream, 18 February 2000: (ExxonMobil Natuna Project, Indonesia)

• • Adoption of the ‘1996 DNV Rules for submarine pipeline systems’, resulting in a safer and lower-cost pipeline design.


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• Norwegian Deep-water Program (NDP)– Andrew Palmer and Associates, UK, evaluated

different codes in order to recommend one particularly suited for deep water applications

– They recommended DNV-OS-F101 • BP (Houston / GoM)

– Intec (Houston) evaluated different codes with the objective to recommend one for the deep-water field MardiGras

– They recommended DNV-OS-F101

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Further development

• Plans for an update of OS-F101• High strength steel (X80+)• New Recommended Practises are being

developed as required (e.g. HT/HP pipelines and pipelines undergoing plastic deformation during installation and operation))

• Large effort on the in-service phase, Pipeline Integrity Management (PIM)

• New EU directive on safety hazards, DNV leads consortium on PIM guidelines

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Summary and conclusions

• DNV pipeline codes have been developed based on an extensive industry collaboration and international Joint Industry Projects (Norwegian participants has played a key role)

• These codes represents cutting edge within pipeline technology

• They are in line with current ISO standards• They are in use world wide• Feedback from the users are being used to update

and improve

6 experience with new dnv pipeline codes

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