David Galbraith

Development of Key Performance Indicators for Offshore Structural Integrity

Key performance indicators (KPIs) are widely used to assess performance against targets, whether these be technical, environmental or financial. Offshore KPIs are used by both duty holders and regulators to assess the reliability of equipment and systems, often they relate to safety systems and the regulator’s interest relates to such systems. The most obvious KPIs include number of fatalities, fatal accident rate, lost time injury frequency and total recordable incident rate, as well as hydrocarbon release incident rates associated with maintaining safety. Many of the “non-headline” KPIs relate to systems that could be critical in the event of an accident and these are of great importance. However KPIs have not yet been developed for the performance of the offshore structural system. Performance standards are a requirement of current UK offshore legislation, although these again are more normally associated with fire and explosion. Since many offshore installations are now in the ageing phase performance measures are increasingly important. This paper described the background to developing KPIs for offshore structures, relating to aspects which are important for both safety and asset integrity. This has been achieved based on a hazard approach, which includes extreme weather, fatigue, corrosion and accidental damage. KPI’s need to be measurable and this aspect has been incorporated in their development. It is proposed that these KPIs will have significant use in providing a basis for measuring structural performance, particularly for ageing installations where a case for life extension needs to be made.Copyright

Ageing accidents - suggestion for a definition and examples from damaged platforms

An increasing number of offshore installations are in the life extension stage of life, resulting in a growing concern among structural engineers about ageing related issues. However, structural engineers are often asked if there is experience of any ageing accidents or if there are examples of such. A safety conscious person would then reply that theory points towards a growing failure rate and hence that ageing accidents will eventually occur. Good engineering practice would then imply that there is no point in waiting for the accident to occur. As responsible engineers we should investigate the hazards and avoid accidents without having to wait for a potentially fatal accident to lead to action. The other possible answer is to question the term “ageing accident”. What is the definition of an “ageing accident”? This paper will investigate into the term “ageing accident” and will propose a definition of this term. Further, this paper will describe some examples of ageing accidents, in particular the many structural failures that have occurred in the Gulf of Mexico hurricanes.Copyright

Lessons Learned From Auditing Structural Integrity Management

As part of its regulatory duties the Norwegian Petroleum Safety Authority (PSA) periodically undertakes audits of the Structural Integrity Management (SIM) functions of the operators of facilities within the Norwegian offshore jurisdiction; typically one or two audits of reasonable detail are undertaken each year, but in addition PSA have also tried a series of mini-audits based purely on interviews without examination of evidence.In many cases certain aspects of the SIM cause the auditors some concern and there is a degree of consistency about those aspects of SIM causing such concern, and on occasion become formal “findings” of the audits. In general the actual execution of SIM activities are performed adequately, but the full understanding of the purpose of SIM and realistic intent and expectation are missing. A particular concern of the auditors is the anticipation of structural form-specific accidental and abnormal events and their incorporation into the SIM.This paper will provide a summary of the more important lessons learnt over several years of auditing, in an attempt to provide industry with a better understanding of the regulator’s expectations of SIM, particularly for installations that are ageing or have unique features.Copyright