Oil and gas consumption is vital for sustained economic growth. With many developing countries progressing towards prosperity, oil and gas consumption demand increases every year. Oil spills due to major accidents hamper the growth and development of the oil and gas industries. Oil spills also cause serious damage to ocean environment and most of the spills take months or years to cleanup. With the recent unfortunate event of a large scale oil spill in Gulf of Mexico, it is clearly evident that such accidents must be prevented from happening or at least efforts must be taken to mitigate the effects of oil spill during such accidents. In order to mitigate the effects, one needs to predict the accurate trajectory of oil films during a spill event, so that appropriate actions can be taken in a timely manner. Over past three decades, simplified empirical correlations are most commonly used in evaluation of the oil slick spreading. Latest developments in computational fluid dynamics and increased computational resources have provided an opportunity to develop a comprehensive model for oil spill problem.
In this current study, a detailed Computational Fluid Dynamics (CFD) based study is proposed to predict the trajectory of oil film during various spill scenarios in shallow water drilling. Three dimensional simulations were conducted for different wave and current conditions. A three phase (Oil, water and air) Volume of Fluid (VOF) multiphase model was used to capture the trajectory of oil film. Open channel wave boundary conditions were used to simulate the propagation of sea waves. The sea water wave profile was described by a Fifth-Order Stokes theory. The presented results clearly show the advantages of using this methodology in predicting the trajectory of oil film during various spill scenarios. The results of these CFD studies show that ocean wave profile and current have important effects on the location, and the extent of oil film on sea surface. The polluted area increases with higher interaction of wave and current. At high wavelength, oil dispersion underwater increases and the extent of oil film on sea surface increases. However at high wave amplitude, the extent of oil film on surface decreases. The presented CFD model clearly shows the value of using CFD simulations to predict the trajectory of oil on the sea surface during various oil spill scenarios. This in turn could help in mitigating the effects of oil spill and also help in clean-up activities.
