Integrity Management of Pipelines and Risers. 2011/Rørledningssemina… · Pipeline & Riser –...

Bente H Leinum and Øyvin Eriksen

Integrity Management of Pipelines and Risers.

How to ensure integrity from well to shore?

© Det Norske Veritas AS. All rights reserved.


Pipeline & Riser – System Thinking

2 2 Slide 2

Systems thinking is the process of

understanding how things influence

one another within a whole

from well to shore

from concept to

operation

from internal flow to

external threats



3

DNV RP-F116 definition of Pipeline System Integrity

The function of submarine pipeline systems is to efficiently and safely

transport a variety of fluids

‘Pipeline system integrity’ is defined as the pipeline system’s

structural/containment function.

There are two main failure modes;

1. Loss of containment – leakage or full bore rupture

2. Gross deformation of the pipe cross section resulting

in either reduced static strength or fatigue strength.



4

Integrity Management in the Operational Phase System Thinking

Flow Integrity Structural Integrity

Functional Integrity Production Integrity



5

Overall framework for the IM-process

Management Processes

Support Processes

Core processes

- Administration (information management, doc control)

- Reporting & Communication - HR (people, competence & training) - Project Management - Contractors & Purchasing - Emergency Preparedness - Learning from Events - Management of Change - Incident Reporting

- Policy & Strategy - Safety Philosophy - Leadership Commitment - Regulatory & Other Requirements

(Compliance) - Planning - External Communications - Audits - Results and Review - Risk Management - Interface Management



System Overview –

From Design during Operation

6

Control systems

e.g.

Equipment

Pipelines

Risers

DFI

Sub-system Approach

Op

era

tion R

ea

din

ess - H

an

do

ve

r

Commissioning & Operation

System Approach

Projects

Operation unit



7

IM-Process in a life cycle perspective

The integrity is

Established during the concept, design and construction

phases

Maintained in the operations phase

Transferred from the development phase to the operations

phase. This interface involves transfer of vital data and

information about the system.



8

Planned development:

Complete Integrity Management (IM) Codes

Management system

DNV-RP-Fxxx

Pipeline

DNV-RP-F116

Risers

DNV-RP-F206

Subsea

DNV-RP-Fxxx

Technical guidelines - DNV recommended practices (RP)

Well

DNV-RP-Fxxx

Harmonized risk philosophy and documents

Both high level and detailed technical guidelines

Flow

DNV-RP-Fxxx

Flexible

DNV-RP-Fxxx

Technical requirements – DNV standards (OS) and ISO



9

Risk assessment and knowing the threat picture

General industry practice a risk based approach should be applied

Identify and manage threats

- combined effect of threats

- changes in threat picture.

Examples: Anchor

18 %

Impact

24 %

Corrosion

27 %

Structural

5 %

Material

10 %

Other

11 %

Nat. Hazard

5 %

Anchor

6 %

Impact

7 %

Corrosion

40 %

Structural

8 %

Material

4 %

Other

18 %Nat. Hazard

17 %

The Gulf of Mexico The North Sea



10

Example 1: Dong Energy – Siri-Field – Si to Ni 10” WI line

Pipeline data 10” WI line (buried), Material grade SML 450 I DFPS. D (outer):273mm, WT (nominal): 14.4 mm (incl. 4mm corrosion allowance), L: 32 km.

Damage to pipeline 6 o’clock pitting corrosion. Wall thickness reduction of up to 70% leak at approx.3km from the Siri platform after 3,5 year in operation (design life: 15 year)

Cause of incident 6 o’clock Microbiologically induced corrosion.

Consequences and solution Replacement of corroded section of pipeline. A cleaning frequency of 1 month was recommended for further operation.



11

Example 1: Dong Energy – Siri-Field

Nini

Cecilie

Siri

10" Water injection

10" Water injection

4" Gas lift

4" Gas lift

3” Gas lift

13 km

32 km

9 km

SCB-2 Water injection

8” Multiphase

12" Multiphase

14" MultiphaseStine S1

Production SCB-1

16" OilOil Storage tank

Umbilical

SAL System

Nini

Cecilie

Siri

10" Water injection

10" Water injection

4" Gas lift

4" Gas lift

3” Gas lift

13 km

32 km

9 km

SCB-2 Water injection

8” Multiphase

12" Multiphase

14" MultiphaseStine S1

Production SCB-1

16" OilOil Storage tank

Umbilical

SAL System

The Siri-Nini-Cecilie-Stine Field

Review of data from corrosion control, surveillance

data and procedures showed that the some part of

the pipeline integrity management system had not

been satisfactory implemented or in accordance

with own control program.

Management commitment

Revamp of Integrity Management System



12

Example 2: Online monitoring of Ship Traffic

The ship specific information found in the AIS data can be improved by joining the sources

with a ship register

DNV holds a comprehensive ship register which is continuously monitored and updated

Other supporting data sources can be included in the DNV data model as e.g. pipeline

data,…

Aggregated data / export

For ship types and sizes

For selected time frame and area

Prepared for GIS presentation (selected grid )

Etc.

Real time AIS

data

Ship ID

Position (long/lat)

Speed

Etc.

Continuous data capture and processing

Modeling of:

Environmental performance

Safety analysis

Pipeline inspection planning (3rd party activity)

Other…

Ship register

Ship ID

Ship type

Ship particulars, size

Machinery details

Capabilities

Anchor size

Cargo types



Example 2: Online monitoring of Ship Traffic - Trawling

13

Motivation: The size of trawl gear has increased

over the last decades and trawling may impose

larger loads than the pipelines originally was

designed for.

Trawl Tracking: AIS (Automatic Identification

System) data can be used to track trawling activity.

Trawling Equipment: Each individual trawler has

been identified. Most of these have provided

information on equipment used

Pipeline trawl crossing frequency for different

equipment categories is calculated along the

pipeline route

Together with pipeline data and results from

external pipeline survey, this forms the basis for

- more detailed load analysis

- optimised mitigation actions (e.g. rock dumping)

- focused inspections (w.r.t. 3 party threat)

Fishing vessels 1000 - 4999 Gt

Example of fishing vessels & pipeline network

(density plot)



Example 2: Pipeline vertical config.and trawl crossing frequency

14

AIS_Total = Total number of crossings, AIS_CW_6-7_5T = Crossing with Clump weight between 6.0 and 7.5 tones



Summary - Encourage system thinking

Interface management

Increased awareness

- know your system

- build cross discipline competence

- ensure transfer of experience

Compliance and Performance

- management commitment

15



16

Safeguarding life, property

and the environment

www.dnv.com

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