Enhancing Offshore Safety: Preventing Hydrocarbon Releases Due to Pipework Vibration

1. Improving Safety – Reducing Hydrocarbon ReleasesPipework Vibration / Fatigue Awareness Stuart McGregor Jeremie Neillo Senior Project Engineer Business Development Manager Date: 30th June 2010 Department: Plant Integrity

2. Purpose Background • Hydrocarbon releases are a major risk offshore • Accounts for 33% of all dangerous occurrences reported to HSE • A significant proportion are caused by vibration fatigue • This is avoidable Purpose To give you an understanding of: • What vibration fatigue is • Why you should consider it • What you can do about it

3. Introduction Doosan Babcock Energy • Have over 110 years experience in the energy sector • Have a long history for designing, supplying and constructing efficient coal fired power plant • Are a leading engineering services provider for the power and energy sector, including offshore • Worked with the offshore industry to develop the AVIFF (avoidance of vibration fatigue failure) Guidelines, which are regarded as the benchmark for managing pipework vibration fatigue • Have significant experience of identifying and resolving vibration issues offshore - reducing HC releases

4. Agenda • What role does vibration play in pipework failure • What are the benefits of good vibration awareness • What is the solution • Worker involvement, what role do you play • The future – how do we keep moving forward

5. What is vibration… Vibration • Small movements rapidly to and fro • Oscillations

6. What is fatigue… Fatigue • Progressive and localized structural damage that occurs when a material is subjected to cyclic loading • Can lead to failure

7. Is Piping Vibration really an issue… • What type of vibration failures can occur • Is this a real threat to us

8. Small Bore Connections (SBC’s) • SBC are at significant risk from vibration fatigue • Potential for failure at the welded connection to main line • Greatest risk on thin walled pipework • What does high risk look like

9. Small Bore Connections

10. Small Bore Connections – With Support Brackets

11. Failure at welds in main lines • Designed to recognised piping code by Competent Engineers • 6” Flare Pipework Failed in service due to Turbulent Excitation • Pipework was observed to be vibrating (at Low Frequency) but no action was taken • When may this be a particular risk

12. Fretting • Pipework vibration can result in Fretting • Fretting can occur when there is relative motion between 2 surfaces • Potential for loss of containment • What fretting risks should we look out for

13. Benefits of Vibration Awareness – Safety & Environmental Significant progress made by industry: • From early 2000’s to today, HC releases in the North Sea caused by vibration fatigue have nearly halved • Some operators have made very significant progress, some have made minimal progress Major KPI by HSE & Insurance industry

14. Before - 2004 10 off HC releases in 2004 5 off were vibration related At least 2 vibration release resulted in controlled shut down 1 off was a 10 day shut down for major weld repairs Minimal proactive management of vibration fatigue Potential for major accident to occur Status - 2004 Major unknown and unmanaged risks Significant impact upon safety and productivity Atleast 10 days lost production (£40-60M) After - 2005 Full vibration review of platform Modifications to reduce rectify identified risks Ongoing maintenance & healthcare plan in place Total cost including modification approx £1M 10 off vibration failures since 2005 No controlled shut downs Status 2010 Risks known and being proactively managed Minimal impact upon safety and productivity Risks ALARP – As Low As Reasonably Practicable Benefits of Vibration Awareness – Case Study – North Sea Platform

15. Solutions – The Engineers Role • Follow AVIFF guidance to minimise risks • Initial surveys (office and site based) • Resolve concerns • Ongoing monitoring (annual / following major change) • Consider Vibration • At design stage • Prior to changes / updates • Process change • New plant equipment • Pipework changes (Carbon steel to Super-Duplex)

16. Solutions – What Role Can you Play… • Would would you do if…..

17. Solutions – What Role Can you Play… Keep your eyes and ears open • Pipework vibrating • Leaks / drips • Noise, especially tonal • Changes from yesterday / last trip Don’t assume someone else has reported the concern You can be the eyes and ears of the safety / Asset integrity team

18. Look Out For Clamps – Maintenance & Inspection • Example of critical clamp not been re-instated correctly after intervention work on line

19. Solutions – What Role Can you Play… Look out for….. • Small Bore Connections vibrating • Pipework vibrating • Fretting risks • Small leaks / drips • Noise • Changes since yesterday / last visit • Clamps / brackets refitted correctly

20. The Future – How Do We Keep Moving Forward • Be Proactive • Follow and apply AVIFF guidelines • Implement regular health checks for vibration fatigue • Consider vibration before major changes • Consider vibration at design stage Keep your eyes and ears open Report concerns

21. Stuart McGregor Senior Project Engineer Tel: 01224 224 316 Email: smcgregor@doosanbabcock.com Jeremie Neillo Business Development Manager Tel: 01224 224 315 Email: jneillo@doosanbabcock.com Questions