4 bp pipeline management risk assessment, operation experience and lessons learned - per olav...

8/12/2019 4 BP Pipeline Management Risk Assessment, Operation Experience and Lessons Learned - Per Olav Gartland (Force Technology)

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PTIL seminar on pipeline integrity 9. December 2009

BP Pipeline ManagementRisk assessment, operation experience

and lessons learned

Per Olav Gartland, John Berget and Bente Herfjord

FORCE Technology Norway AS

and

Inge J. Mæland and Alf Inge Lyse

BP Norway




Pipeline Integrity Management

to ensure the technical integrity of the pipeline, i.e.:

to operate within acceptable safety margins and

optimised economy throughout the lifetime

» avoid failures and incidents» re-qualification and life extension of old pipelines

» optimize life cycle cost (LCC)




BP Norway PIM Strategy

Risk AssessmentEvaluate internal/external conditionIdentify critical parameters and accept criteria (KPI s)

MonitoringCorrosion monitoring

Critical process parameters (KPI`)Free span, burial, CP etc.

Status Reporting (quarterly)

Inspection

Internal and external inspection plansDetail inspection planning (scope, inspection method/practical arrangements etc.)Inspection (ILI, ROV)Evaluate inspection results/finding & take actions

Maintenance activitiesCleaning (pig)

General maintenance of valves and pig receivers and launcher.

RiskAssessment

MonitoringInspect ion plan

Imp lementworkscope

Execute Monitor ingInspect ion

Evaluate

Findings Act ions

IN S P E C T IO N & C O R R O S I O N M A N A G E M E N T

Follow up

Update plan

Control




BPs Engineering Technical Practice ETPs

PR 43 Pipeline ETP Rationale and Philosophy

GP 43-17 Pipeline Risk ManagementGIS 43-213 Pipeline Spanning (DNV RP F105)

GP 43-23 Offshore Facilities for Pipelines

GP 43-24 GIS and Mapping

GP 43-26 Offshore SurveysGP 43-36 Pipeline Protection

GP 43-37 Control Systems for Pipelines

GP 43-39 Measurement and Sampling on Pipelines

GP 43-48 Pipeline Operations Organisation Setup

GP 43-49 Pipeline Integrity Management Systems (PIMS)GP 43-50 Pigging, Pig Launchers, and Receivers

GP 43-51 Maintenance and Reliability

GP 43-52 Inspection and Integrity Assessment of PipelinesGP 43-53 Pipeline Intervention and Repair




INTERNAL Load effects

Corrosion caused by

CO2 / HAc

H2S

Bacteria (deposit)

Erosion caused by

particle (sand)

EXTERNAL Load effects

CorrosionCP system malfunction

Coating quality

Bacteria

HISC

Ground movementsEarth quake

Soil movements

3rd party damageImpact (anchoring etc.)

Sabotage

Mechanical defectsFatigue

Vibration

Risk AssesmentFailure Mechanisms during Operation

RISK = Probability (PoF) x Consequence (CoF)




Internal Risk Assessment

Quantitative assessment based on:Corrosion features from In-line Inspection (ILI)CorPos-AD pipeline corrosion model

CO2 (Norsok M-506), HAc, H2S, erosion

Additional models (Cassandra) to be implementedModel combined with ILI data

Qualitative assessment

Bacteria corrosion

Integrity check based on DnV RP-F101

Remaining Lifetime EstimationTime to next inspectionMonitoring program parameters and associated critical values




CorPos-AD

Database

Graphs

Risk analysis and

Safety Check

Corrosion modeling

Flow modeling

OLGAImport inspection data

Import monitoring data

Import production data

Import chemical injection data

Reports

Combine corrosion model

and monitoring/inspection

CorPos-AD, overview




Case 1: Hod 12 Multiphase pipeline




Case 1: Hod multiphase pipeline ILI

Hod

0.0

2.0

4.0

6.0

8.0

10.0

12.0

mai.90 jan.93 okt.95 jul.98 apr.01 jan.04 okt.06 jul.09 apr.12

Time

C o r r o s i o n d e p t h ( m m ) Inspection dataMFL UT

12 Hod multiphase pipeline (CS)

Operation from 1990

ILI 1993, 1994, 1995, 1998, 2004, 2009

Corr. Inhibitor injection 1993




Case 1: CorPos-AD analysis of Hod multiphase pipeline

CorPos-AD analysis based

on:

Production data

Inhibitor injection data

CR-profile obtained for 4time periods

Max corroded depth vs

time from integration

0

0.2

0.4

0.6

0.8

1

1.2

1.4

0 2000 4000 6000 8000 10000 12000 14000

KP [m]

C o r r o s i o n r a t e [ m m / y e a r ]

CR (1991-1993)

CR (1993-1998)

CR (1998-2000)

CR (2001-2008)




Case 1: CorPos-AD analysis of Hod multiphase pipeline

Hod

0.0

2.0

4.0

6.0

8.0

10.0

12.0

mai.90 jan.93 okt.95 jul.98 apr.01 jan.04 okt.06 jul.09 apr.12

Time

C o r r o s i o n d e p t h

( m m )

Inspection data

Corpos-AD analysis 2009




Case 1: Hod Multiphase pipeline CorPos-AD RiskAssessment

ILI data from 2008

Design lifetime = 7

years (2015)

Risk status at end of

design life = OKEstimated remaining

lifetime > 50 years

Future ILI frequency 5years

Zone 1- Pit growth prediction

Critical pit depth according toDnV R P-F101

Blue lines: Pit growth model prediction from 2008 to 2015




Case 1: Major challenges

Wax deposits in pipeline

UT pig data more sensitiveto residual wax than MFLpig data

MFL and UT data have

different accuracy andresolution

Modification of pig hardwareand software over timemakes it difficult to evaluate

time evolution of corrosionfeatures (e.g. to extractcorrosion rates)




Case 1: Hod Multiphase - Corrosion Monitoring

Quarterly status reporting:




Case 2: Ula - Ekofisk 20 oil export pipeline

Ula

Tambar

Cod

20 UTS PipelineLength: 70 km from Ekofisk toUla

13 km from Ula to Y Assembly

Ekofisk 2/4 J

Gyda

Ula/GydaWye

Assembly

10 Cod Gas Export(Decommisioned)Length: 26.4 km 8 Tambar Production Flowline

(Decommisioned)Length: 16 km

20 Gyda Oil Export PipelineLength: 24.8 km

10 Spool from Tambar to UGIPLength: 60 m

36 Ekofisk to Teeside

Total length 170 km




20 UT pig Launching..





Production start in 1986

UT

MFL

MFL

Method

Pitting with depth up to 4.4 mmbefore Y-connection

Pitting with depth up to 6.9 mmbefore Y-connection

No findings

Findings

2006

2004

1997

Time of inspection

2006 ILI





Low production rates

Increased water holdup

Dilution of inhibitor

Changes leading to improved corrosion control

Increased inhibitor injection rates

Increased frequency of cleaning pig runs

Increased frequency of intelligent pig runs

Increased production rate (Tambar)

CorPos/OLGA analysis

0

5

10

15

20

25

30

1992 1994 1996 1998 2000 2002 2004

Year

M a x w a t e r h o l d u p ( % )

Before Y-connection

After Y-connection





Quarterly status reporting:




Lessons Learned (1)

Proper cleaning of pipelines prior to inspection is very important

to ensure good / reliable and comparable inspection data.

Good planning and coordination of the operation is important to

ensure effective utilization of expensive rental equipment

(cleaning pigs and inspection tools)

Dimension control by gauge plate

Hook devices both in front and back of the cleaning/inspection

pigs to ease the pig launch and retrieval from pig launcher /

receiver.




Lessons learned (2)

Data on corrosion rates (CR) required for lifetime estimation

ILI data strongly dependent on method (MFL, UT) andmethod development Difficult to obtain corrosion

rates from ILI data

No corrosion monitoring units on pipelines.

Probes top-side not relevant for the entire pipeline.Good experience from using CR data obtained from CorPos-AD model, adjusted to fit ILI data if required

Low production rates may lead to water accumulation and poor

inhibitor performance in oil export lines with low water content(1-2 %) High frequency of cleaning pigs required




Major challenges in the future

Internal

MIC (Microbial Influenced Corrosion)

External

How determine anode depletion for buried pipelines?

How to inspect for HISC risk of CRA pipelines?

4 bp pipeline management risk assessment, operation experience and lessons learned - per olav...

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