Piper Alpha and the Evolution of Inherently Safe Design and Integrity Management: An Overview of Interpretations and Lessons Learned

The development of Inherently Safe Design, Corrosion and Integrity Management as a genuine combined engineering discipline has evolved largely over the past 30 years or so, with significant acceleration and urgency after the Piper Alpha offshore disaster in the North Sea in 1988. The concepts and practices have matured with many significant changes implemented across the world offshore regions. Even after more than 20 years, the emanating point for sweeping changes has been the Cullen Report and the UK North Sea industry. This paper offers an interpretation of the early and later lessons learned, as applicable and relevant to deepwater and by analogy arctic offshore assets and pipelines, whereupon conditions are harsh and accessibility very limited. The particular focus is on the so called ‘secondary tier’ points related to materials performance, corrosion, and integrity; the understanding monitoring and control of such matters and failures can be critical in reconstituting integrity, if pragmatic life cycle safety and performance are to be recognized. It is argued that modes of failure such as those related to loss of material properties, corrosion, erosion, environmental cracking, and other degradation phenomena, have become far more critical in deepwater and arctic projects. This is mainly due to repair, retrofit, or re-habilitation being invariably far too costly if not virtually impossible in practice. The authors’ use career wide experiences post Piper Alpha to highlight the worries and concerns offering rational pragmatic solutions, illustrated through related case histories. Conclusions and recommendations are based on predictions, interpretations, and viable solutions. Additionally, industry disconnects between technology transfer under this tutelage are identified. The new methods of ‘concurrent design’ and inherently safe design are discussed, and in the context of mechanical, materials, and corrosion engineering advances are related to the use of Key Performance Indicators (KPIs) and Key Failure Indicators (KFIs), for best life cycle integrity and knowledge management. This approach is considered very important for deepwater and arctic assets where ‘surprise’ failures, environmental and political ‘snafus’ are not really an option, and thus more purposeful design investment at CAPEX is vital rather than at OPEX, and the ‘gray’ zone between the two cost centers must be therefore be better reconciled, perhaps it is argued through the concept of an extended CAPEX.Copyright © 2010 by ASME