Eulerian large-eddy simulation of deep-sea hydrocarbon plume with multi-component gas bubble dissolution.

The multiphase hydrocarbon plume released from a deep-sea oil spill usually contains a large amount of natural gas bubbles that provide the buoyancy force to raise the plume. The natural gas consists of various alkane compounds that can experience considerable dissolution in seawater in the deep-sea environment. This gas dissolution effect causes the reduction of the total buoyancy force as the plume rises, strongly affecting the structure and dynamics of the hydrocarbon plume in the region near the release source. In this study, a fast Eulerian large-eddy simulation (LES) model is developed to model the effects of multi-component gas bubble dissolution on the dynamics of the plume. The LES model is applied to simulate a subsea blowout from a depth of 700 meters, with an initial gas compound ratio of methane/ethane/propane $=$ 87.5/8.1/4.4. Both instantaneous flow field and statistical characteristics of the plumes will be presented in this talk.