Key performance indicators for environmental contamination caused by offshore oil spills

Oil spills during offshore operations are likely to cause severe contamination of the sea. The identification of the environmental effects of accidental releases from offshore oil and gas facilities plays a crucial role in the prevention and mitigation of marine pollution. Key Performance Indicators (KPIs) are largely recognized as an effective tool to address and communicate multifaceted issues related to accidental events in the framework of risk management. In the context of Oil Spill Risk Assessment (OSRA) studies, this study proposes a set of KPIs addressing the potential environmental contamination caused by on-surface oil spills from offshore oil and gas installations. A layered approach was defined, based on three different levels of KPIs having an increasing complexity and providing an increasing amount of information. The environmental KPIs defined allow a preliminary quantitative assessment of the environmental contamination due to the oil spill scenarios defined in the ENVironmental hazards IDentification (ENVID) studies carried out for oil and gas installations, providing a preliminary ranking of the expected environmental effects of the spills and supporting their prioritization in order to select those which should undergo a more accurate Environmental Risk Assessment study (ERA).