ABSTRACT
Prevention of hydrocarbon leaks is important; they are the most critical precursor events that may lead to major accidents, such as in the case of Piper Alpha. The number of hydrocarbon leaks on offshore production installations on the Norwegian Continental Shelf peaked just after year 2000, with more than 40 leaks per year with initial rate above 0.1 kg/s The Norwegian Oil and Gas Association ran a reduction project from 2003 until 2007, which resulted in ten hydrocarbon leaks above 0.1 kg/s in 2007. The number of leaks increased in the years after 2007, and was in average 15 in the period 2008-2010, without any significant increase in the number of installations. The Norwegian Oil and Gas Association initiated a new initiative early in 2011 in order to reduce the number of hydrocarbon leaks further. The initiative will be completed at the end of 2013, but has already started to show promising results. A study performed by the project concludes that more than 50% of the leaks are associated with failure of operational barriers during manual intervention into the process systems. Human and organizational factors are dominating with respect to circumstances and root causes. The study has further demonstrated the high importance of verification as an operational barrier, and has shown that many of the failures do not have multiple operational barriers at the end. This finding is crucial for how manual interventions in pressurized process systems should be planned and carried out. This paper presents the analysis of hydrocarbon leaks, including its initial results in 2011 and 2012. The importance of operational barriers and verification is illustrated through statistics and case studies.
