This document provides information on an offshore platform asset integrity management presentation given by Cdr. Balakrishnan G Nair. It begins with background on Nair and his employer, Saipem, an engineering and construction company. It then discusses asset integrity management and challenges in maintaining the structural integrity of aging offshore platforms. Specific issues addressed include design life versus life extension, efficacy of integrity programs, tools used, and technical challenges around lack of historical data as platforms age. The presentation provides a case study on the 1980 Alexander L. Kielland accident and proposes ways forward such as improved monitoring techniques and through-life weight control.

1. Cdr. Balakrishnan G Nair (IN Retd)
Present
Affiliation
Saipem India Projects Private Limited
Academic
Qualification
B.Tech (Naval Architecture), Cochin University of Science & Technology, 1983 - 87
PG (Naval Construction), IIT Delhi, New Delhi, 1988 -90
PGDBA (Operation Management), Symbiosis, Pune, 2005- 07
Area of
Specialization
Naval Architecture, Warship Design, Steel Structures, Structural Fabrication,
Survey, Project Management.
Achievements/
Awards
Admiral Bharat Bhushan Award for best Ship Design project at IIT Delhi, 1990
Commendation by Commander-in-Chief, Southern Naval Command, 1997
‘Certified Value Engineer’, 1998
Commendation by Chief of the Naval Staff, 1999
'Operation Vijay' Medal for significant technical contribution to Indian Navy, 2000
Member, Indo-Russian team for Technical Acceptance of BrahMos Missile Launcher, 2004
‘Six-Sigma – Green Belt’, 2010
Associate Member, The Royal Institution of Naval Architects, London, 2012
Paper Title Asset Integrity Management of offshore platforms and associated issues & challenges
Photogra
ph of
speaker

2. ASSET INTEGRITY MANAGEMENT OF OFFSHORE PLATFORMS,
ASSOCIATED ISSUES & CHALLENGES
Cdr Balakrishnan G Nair, (IN Retd),
Chief Engineer, Saipem India Projects Private Limited

3. CONTENTSCONTENTS
3
1.1. ABOUT SAIPEMABOUT SAIPEM
2.2. BACKGROUNDBACKGROUND
3.3. CASE STUDYCASE STUDY
4.4. DESIGN LIFE & LIFE EXTENSIONDESIGN LIFE & LIFE EXTENSION
5.5. EFFICACY OF ASSET INTEGRITY MANAGEMENTEFFICACY OF ASSET INTEGRITY MANAGEMENT
6.6. TOOLSTOOLS
7.7. ISSUES & CHALLENGESISSUES & CHALLENGES
8.8. WAY AHEADWAY AHEAD
9.9. REFERENCESREFERENCES

4. 4
ABOUT SAIPEMABOUT SAIPEM

5. ABOUT SAIPEMABOUT SAIPEM
5
 Operating in more than 60 countries
 > 50,000 employees from >130
nationalities
 11 fabrication yards in 5 continents
 29 engineering and project execution
offices worldwide
 Revenues
– 2014 ~13 B€
 Backlog
– June 2014 24.2 B€
Saipem A Major Multicultural E&C & Drilling Contractor

6. ABOUT SAIPEMABOUT SAIPEM
6
A Leading Global EP(I)C General Contractor

7. ABOUT SAIPEMABOUT SAIPEM
7
An impressive track record over more than 60 years

8. ABOUT SAIPEMABOUT SAIPEM
8
Global Presence with a Multilocal Emphasis

9. ABOUT SAIPEMABOUT SAIPEM
9
Global Presence with a Multilocal Emphasis

10. ABOUT SAIPEMABOUT SAIPEM
10
Saipem Businesses and BUs

11. ABOUT SAIPEMABOUT SAIPEM
11
Saipem E&C: Complete Range of EPC/EPIC Services

12. ABOUT SAIPEMABOUT SAIPEM
12
Saipem’s Assets: Major Engineering Centres

13. 13
BACKGROUNDBACKGROUND
TO ASSET INTEGRITY MANAGEMENTTO ASSET INTEGRITY MANAGEMENT

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BACKGROUNDBACKGROUND
- During the Life Cycle of an Offshore Asset, its Integrity can
come into question any time.
- Many offshore installations the world over are reaching or
being in excess of their original anticipated design life.
- While ageing of systems can affect performance, ageing of
the supporting structure can have very significant effects.
- The need to assess integrity of offshore assets particularly
when they are nearing their design life requires no emphasis.

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BACKGROUNDBACKGROUND

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BACKGROUNDBACKGROUND
- When an offshore asset reaches its design life, often
there is demand that it be continued to be deployed:
- To produce oil/gas either from the original fields or
- To serve as base for neighboring wells.
- Such assets are likely to remain operational for a
significant period of time in foreseeable future.
- Demonstration of structural integrity beyond its
design life is a must, as ageing affects performance.

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BACKGROUNDBACKGROUND
Structural performance during life extension

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BACKGROUNDBACKGROUND
- Fig shows variations of deterioration of structural integrity with time.
- The key issue for ageing installations is the increased uncertainty
associated with their performance in the later stages.
- Changes in ownership and cycles of contracting out structural
maintenance activities may contribute to loss of corporate knowledge.
- Similarly, the change from Certification to Verification may also
contribute to loss of corporate knowledge.
- This body of knowledge encompasses Design Criteria, the history of
inspection and repair etc.
- In turn, this impacts understanding of current condition of structure.

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BACKGROUNDBACKGROUND
- Presence of fabrication defects is of relevance in
ageing installations.
- This is particularly so, as they turn significant
under sustained harsh environment.
- The changes in the following are additional factors
that need to be considered:
- Inspection approaches (detailed to global)
- Codes of practice
- Environmental criteria

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CASE STUDYCASE STUDY

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ALEXANDER L. KIELLANDALEXANDER L. KIELLAND
Edda 2/7C and Alexander L. Kielland (right)

22. 22
- The rig Alexander L. Kielland was built as a mobile drilling unit at a
French shipyard and delivered to Stavanger Drilling in July 1976.
- The floating drill rig was not used for drilling purposes but served as a
semi-submersible 'flotel' providing living quarters for offshore workers.
- In 1980 the platform was working in the Norwegian north sea
providing offshore accommodation for production platform Edda 2/7C.
- In the evening of 27th
Mar 80, > 200 men were off duty in the
accommodation onboard Alexander L. Kielland.
- The wind was gusting to 40 knots with waves up to 12 m high. The rig
had just been winched away from the Edda production platform.
- Disaster struck and of the 212 people aboard 123 were killed, making
it one of the worst disaster in Norwegian offshore history since WWII.
ALEXANDER L. KIELLANDALEXANDER L. KIELLAND

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SEQUENCE OF EVENTS THAT UNFOLDEDSEQUENCE OF EVENTS THAT UNFOLDED
- Around 18:30 those on board the rig felt a 'sharp
crack' followed by 'some kind of trembling'.
- Suddenly the rig heeled over 30° but stabilized.
- Five of the six anchor cables had broken, the one
remaining cable preventing the rig from capsizing.
- The list kept increasing, at 18.53 the remaining
anchor cable snapped.
- The rig turned turtle taking down 123 onboard.

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In March 1981, the Investigation Report brought out
the following:
-The rig collapsed owing to a fatigue crack in one of its
six bracings (bracing D-6), which connected the
collapsed D-leg to the rest of the rig.
-The crack was traced to a small 6mm fillet weld which
joined a non-load-bearing flange plate to this D-6
bracing.
-This flange plate held a sonar device used during
drilling operations.
FINDINGS OF THE INVESTIGATIONFINDINGS OF THE INVESTIGATION

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FINDINGS OF THE INVESTIGATIONFINDINGS OF THE INVESTIGATION

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- The poor profile of the fillet weld contributed to a
reduction in its fatigue strength.
- There were considerable amounts of lamellar tearing in
the flange plate and cold cracks in the butt weld.
- Cold cracks in the welds, higher stress concentrations
due to the weakened flange.
- Cyclic stresses, common in the North Sea.
- All the above played a collective role in the collapse.
FINDINGS OF THE INVESTIGATIONFINDINGS OF THE INVESTIGATION

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FINDINGS OF THE INVESTIGATIONFINDINGS OF THE INVESTIGATION
Part of the bracing that failed during the accident
(On display in the Norwegian Petroleum Museum)

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FINDINGS OF THE INVESTIGATIONFINDINGS OF THE INVESTIGATION
- After initial trigger, structural elements failed in
sequence, destabilizing entire structure.
- The design of the rig was ‘flawed’ owing to the
absence of structural redundancy.
- Additional accommodation blocks were added
to the platform in 1978, so as to accommodate
386 persons!

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DESIGN LIFE & LIFE EXTENSIONDESIGN LIFE & LIFE EXTENSION

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DESIGN LIFE & LIFE EXTENSIONDESIGN LIFE & LIFE EXTENSION
- “Design Life” and “Life Extension” are to be understood
clearly particularly in the context of ageing installations.
- The Design Life of an installation is not well defined in
codes and standards (See Table in the following slide).
- For the purposes life extension, definitions of Design Life
as in ISO-2394 & ISO-19902 are considered appropriate.
- This can be adapted as 'The assumed period for which a
structure is to be used for its intended purpose’
- This is ‘with anticipated maintenance but without
substantial repair on account of ageing processes'.

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DESIGN LIFE & LIFE EXTENSIONDESIGN LIFE & LIFE EXTENSION
Code, Standard or Guidance Definition of Design Life
ISO 19900, Petroleum and natural gas
industries - General requirements for
offshore structures
Service requirements - the expected service life shall be specified in
design.
ISO 19902 - Fixed steel installations
The assumed period for which a structure is to be used for its
intended purpose with anticipated maintenance but without
substantial repair being necessary
NORSOK - N001
Structures shall be designed to withstand the presupposed repetitive
(fatigue) actions during the life span of the structure.
HSE Design & Construction Regulations
1996
Reg. 4 - need to ensure integrity of a structure during its life cycle.
Processes of degradation and corrosion to be accounted for at the
design stage; Reg. 8 - need to maintain integrity of structure during
its life cycle.
DnV - Classification Note 30.6, Structural
reliability methods
Definition of design life: ‘The time period from commencement of
construction to until condemnation of the structure’.
D.En / HSE Guidance Notes
Calculated fatigue life should not be less than 20 years, or the
required service life if this exceeds 20 years. The (cathodic
protection) current to all parts of the structure should be adequate
for protection for the duration of the design life.

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EFFICACY OFEFFICACY OF
ASSET INTEGRITY MANAGEMENTASSET INTEGRITY MANAGEMENT

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EFFICACY OF ASSET INTEGRITY MANAGEMENTEFFICACY OF ASSET INTEGRITY MANAGEMENT
- The structural integrity management of ageing
installations requires:
* Accurate knowledge of the condition of a structure
with respect to fatigue & corrosion;
* Understanding of response of the structure in aged
condition.
- Appropriate inspection techniques & structural analysis
methods are necessary.
- It is important to achieve the correct balance between
structural analysis and inspection.

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EFFICACY OF ASSET INTEGRITY MANAGEMENTEFFICACY OF ASSET INTEGRITY MANAGEMENT
The successful implementation of a structural integrity
management plan also depends on:
-Understanding the degradation processes.
-Availability of appropriate level of data on actual
condition of the structure.
-Reliable assessment methods.
-Implementation strategy to deal with increasing risk of
failure with time.

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EFFICACY OF ASSET INTEGRITY MANAGEMENTEFFICACY OF ASSET INTEGRITY MANAGEMENT
- Asset Integrity Management programs for Oil & Gas
Industry are generally tailored for specific asset.
- They take a comprehensive approach towards
managing risk throughout the life of the asset.
- It encompasses core elements of an effective risk
management consisting of:
- Integrity Management (structure& equipment)
- Configuration Management
- Emergency Response.

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A.I.M - WHAT IT ENTAILSA.I.M - WHAT IT ENTAILS
Integrity Management
-Should include asset-specific survey planning, suitable software to
manage & track asset’s structural condition & program
management.
Configuration Management
-Must provide industry-proven offshore stability monitoring and
load management combined with periodic configuration audits.
Rapid Response Damage Assessment
-It should employ customized salvage response plans allowing for
rapid evaluation of damaged conditions to an offshore asset in
emergency situations.

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TOOLSTOOLS

38. 38
TOOLS ENABLING A.I.MTOOLS ENABLING A.I.M
- Physical match of facility Vs as-built documentation
- Topside Weight Control Reports
- Corrosion, Erosion and Thickness Records, Marine growth
- A risk evaluation and identification of hazards and failure modes
- Prospect of wave-in-deck loading (represented by reserve freeboard ratio)
- Report on experiences of adjacent fields and actual field Sea-states
- Scour Survey
- Seabed subsidence information
- Fatigue Strength Assessment
- Pushover Analysis & RSR

39. 39
ISSUES & CHALLENGESISSUES & CHALLENGES

40. 40
ISSUES & CHALLENGESISSUES & CHALLENGES
-The subject of ageing installations is of great
significance for the offshore industry and will remain so
with an ever-increasing population of ageing structures.
-This significance is increasingly reflected in the content
of current regulations, codes, standards & RPs.
-They give recognition to the requirement that specific
consideration of the ageing process is required.
-Those assets which did not have a well established
A.I.M program during their life cycle would be more ill
prepared for life extension.

41. 41
ISSUES & CHALLENGESISSUES & CHALLENGES
-The structural integrity management of ageing
offshore installations is a complex process.
-The performance of ageing installations can be
highly variable though deterioration can occur
at any stage in the life cycle, depending on:
- The design of the structure
- Fabrication quality
- In-service inspection and repair activities
- Quality & extent of structural assessment

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ISSUES & CHALLENGESISSUES & CHALLENGES
-There is the issue of deterioration which is not
known, either because of inadequate inspection
or because the component is un-inspectable.
-This also requires competency in the wide range
of activities essential to the structural integrity
management process.
-Operators have tended to treat installations in
the life extension phase in the same way as
installations operating within their design life.

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ISSUES & CHALLENGESISSUES & CHALLENGES
Other technical issues to be addressed are:
-Accelerating local fatigue beyond design limits
-Widespread fatigue damage and subsequent
loss of redundancy.
-Maintenance of corrosion protection and
allowances.
-Pile integrity, accumulated accidental damage.

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ISSUES & CHALLENGESISSUES & CHALLENGES
- Data on the original design criteria, material
properties, fabrication quality and installation
performance are required but may not
necessarily be available.
- Difficult to obtain a match between as built
document and the physical condition.
- Even in cases where original WCR are
available, it s unlikely that through life record
of weight monitoring data is available onboard

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ISSUES & CHALLENGESISSUES & CHALLENGES
- Data on Corrosion, Erosion and Thickness
Records, Marine growth particularly in
inaccessible region are difficult to obtain.
- Seabed subsidence data and scour survey may
be unavailable/ costly to obtain or practically
impossible.
- Unless an effort has been made over a period
of time it is unlikely that data on sea-states
actually experienced by adjoining platforms
are available in discernible manner.

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WAY AHEADWAY AHEAD

47. 47
WAY AHEADWAY AHEAD
- There is a need for the development and application of
new inspection techniques, e.g. on-line structural
monitoring methods.
- This would enable continuous monitoring of the
structural integrity of offshore installations during the
life extension phase.

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WAY AHEADWAY AHEAD
- Through life weight control mechanisms that highlight
significant changes that can affect structural integrity
caused by deviation from original design conditions.

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WAY AHEADWAY AHEAD
- It is important to take advantage of
inspecting and testing of components
from decommissioned structures to
establish the effects of ageing.
- This is particularly beneficial for
components that are difficult to inspect.

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WAY AHEADWAY AHEAD
- Create an electronic model as close to
the current physical status of the
platform.
- As and when the situation demands, run
a SACS analysis as against the current
environment condition.
- Undertake Seismic Analysis if applicable.

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WAY AHEADWAY AHEAD
- Carry out a FEM analysis for critical joints.
- Perform a Fatigue Analysis based on
knowledge of the cycles the platform was
exposed to.
- Perform a Push-over Analysis for ensuring
availability of adequate Reserve Strength Ratio
(RSR).
- Predict the residual life based on available
corrosion margin.

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REFRENCESREFRENCES

53. 57
REFERENCESREFERENCES
1. Offshore Asset Integrity Management - Program for Life Cycle
Maintenance– A publication by ABS Nautical Systems Division
2. Life Extension issues for ageing offshore installations - A. Stacey,
M. Birkinshaw, J. V. Sharp - OMAE2008
3. Lifetime extension of ageing fixed offshore platforms and subsea
assets AIM Forum, Bureau Veritas – Kuala Lumpur 17-18th September
2013
4. Technical challenges relating to continued safe operation of Ekofisk
platform structures arranged, Michael Erik Hall May, 2007
5. Repairing of tubular joints damaged under cyclic loadings: An
innovative technique, T S Thandavamoorthy, A R Santhakumar, A G
Madhava Rao – 12WCEE, 2000
6. Risk Assessment Method for Offshore Structure Based on Global
Sensitivity Analysis, Zou Tao, Li Huajun and Liu Defu, 2012

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REFERENCESREFERENCES
7. Surveys using Risk-Based Inspection for The Offshore Industry.
ABS, 2003
8. Structural Reliability Applications in Risk-Based Inspection Plans for
Semi-Submersible Floating structures, A. Ku, Bernardo Nietmann, V.
Krzonkalla , et al, Deep Offshore Technology 2012
9. Risk based fatigue inspection planning – state of the art, Tom
Lassen, 5th Fatigue Design Conference, Fatigue Design 2013
10. An extended methodology for Risk based Inspection Planning, J.T
Selvik, P. Scarf, T. Aven – Mar 2011
11. Structural Integrity Management- from cradle to grave,
Mohammad Nabavian – 2013
12. Asset Integrity Management extends reach, M.F Renard, 2013

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THANK YOUTHANK YOU