Use of accident precursor event investigations in the understanding of major hazard risk potential in the Norwegian offshore industry

The recent offshore accidents at the Macondo and Montara fields in the 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 realised by the Petroleum Safety Authority in Norway, which has a specific requirement for such learning in its regulations. However, an unfortunate practice has been developed by the major players in the Norwegian offshore industry, whereby potential is severely and systematically downplayed, probably to limit the negative exposure if the actual potential consequences were known. The present article analyses 45 major accident precursor investigations in order to demonstrate the effect of downplaying the potential of major accidents. It demonstrates how the risk potential classified in investigation reports has a random relationship to the more objective risk potential, as shown in the national risk indicator project conducted by the Petroleum Safety Authority. This is further demonstrated by comparing company investigations with authority investigations in four cases where parallel investigations were performed.