Metocean and Oil Spill Modeling

Abstract

Abstract This paper sets out to explain the global methodology developed by Total to improve the reliability of oil spill drift modeling by developing metocean skills in-house. The role of oil spill modeling is not at present considered essential during an oil spill, despite the fact that its advantages have been clearly identified. Actually, model predictions should make it possible to –Forecast the drift of an oil slick–Identify the areas where the intervention teams should take action–Predict the period and areas that could be impacted–Inform neighboring installations, authorities and NGOs. Oil & Gas Companies initially showed great interest in this new tool but, due to a series of poor modeling results, its place in the oil spill response was redefined. After several studies, these controversial results appear to originate in the questionable reliability of the current and wind data. To remedy this, Total created a "metocean & oil spill modeling" system to improve the quality of this data, which in turn will bring an improvement to oil-spill drift modeling results. This paper explains the main steps of this system and details its advantages. Its overall functioning has been tested in Total on a recent event: a gas and condensate leak on the Elgin platform in the North Sea. The main actions and conclusions are developed in this paper. A retrospective analysis of the results on the Elgin event shows the system is effective, since the reliability of the predictions is estimated to be about 92% for the first day's forecast and about 77% for 2 days. So now, thanks to the improvements in metocean information, oil spill models can be considered as reliable tools for use in oil spill response.