The following is a suite of papers based on extensive research in 2011, which together have analyzed hydrocarbon leaks on Norwegian offshore installations in detail. The papers will be published through 2012. Links to publishers will be added as the papers are published.
On the analysis of hydrocarbon leaks in the Norwegian offshore industry
Abstract: There have been several major offshore accidents in different offshore regions since 2005. In Norway there have been several very serious near-misses during the last ten years, several of which involving serious hydrocarbon leaks with catastrophic fire and explosion potential. All these severe occurrences demonstrate the importance of learning from major accident precursors in order to appraise the risk potential involved in critical offshore operations. This paper is based on analysis of about 175 hydrocarbon leaks in the period 2001-2010. Regulatory requirements in Norway are aimed at preventing as far as possible such occurrences during night time, but the analysis shows that this has been far from successful. The industry has for many years claimed that the maintenance personnel are the main group of employees involved in causing these leaks. This study has shown that leaks during the execution of maintenance and modification are less than half of the leaks, and that failures during the preparation for carrying out maintenance tasks are more frequent. Such preparations have often been conducted during night shift. The analysis gives a strong incentive to change this practice.
On the use of major accident precursor event investigation in relation to understanding of risk potential in Norwegian offshore industry
Abstract: The recent offshore accidents at Macondo and Montara offshore fields in US and Australia have demonstrated the importance of learning from major accident precursors in order to appraise the risk potential involved in critical offshore operations. This is fully realized by Petroleum Safety Authority (PSA) [Norway] who has a specific requirement for such learning in their regulations. But an unfortunate practice has been developed by the major players in the Norwegian offshore industry whereby the potential is severely and systematically downplayed, probably to limit the negative exposure if the real potential consequences were known. The paper presents an analysis of about 40 major accident precursor investigations, in order to demonstrate the effect of downplaying of the major accidents potential. It is demonstrated how the risk potential as classified in the investigation reports has a random relationship to a more objective risk potential, as revealed in the national risk indicator project conducted by PSA. This is further demonstrated by comparing company investigations with authority investigations in four cases where parallel investigations were performed.
On the analysis of hydrocarbon leaks from offshore installations in a work process context
Abstract: The recent offshore accidents at Macondo and Montara offshore fields in US and Australia have demonstrated the importance of learning from major accident precursors in order to appraise the risk potential involved in critical offshore operations. One of the most common type of precursor events on offshore installations is hydrocarbon leaks. From the work by Petroleum Safety Authority [Norway] there is an extensive database available on these precursor events, in most cases involving incident investigations performed by the company. The Norwegian Association of Offshore Operators (OLF) has launched an initiative in order to try to understand the reasons behind the high frequency of these precursor events, and propose actions to mitigate the situation. The paper presents an analysis of about 175 major accident precursor (hydrocarbon leaks) investigations, in order to demonstrate how these may be analysed in a work process context, involving planning, preparation, execution and reinstatement. The observations from the analysis are focused on the times at which the leaks occur, and the implications of these times for prevention of precursor events. Finally, some recommendations for the management and supervision on the offshore installations are included.
Development of models of maintenance work in process plants on offshore petroleum installations
Abstract: There have been several major offshore accidents in different worldwide regions since 2005. In Norway there have been several very serious near-misses during the last ten years, several of which involving serious hydrocarbon leaks with catastrophic fire and explosion potential. One of the main findings of previous studies is that manual intervention is the main cause of the majority of leaks. Several recent papers have focused on modelling of such works. This paper is based on analysis of about 70 major accident precursors (hydrocarbon leaks) in the period 2006-2010. The purpose has been to improve the models that have been published previously, in order to update models with the most recent data. This study has shown that two operational barriers are not as often available as previously assumed. Verification of the performance of work is often the only available barrier, which implies that this is an extremely crucial barrier.