Numerical study of underwater fate of oil spilled from deepwater blowout

• A numerical oil spill model is developed for contingency planning.
• The underwater fate of oil spilled from deepwater blowout is investigated.
• The model is verified by comparing with field experimental data.
• The model is applied to a hypothetical scenario occurring in the South China Sea.

Based on Lagrangian integral technique and Lagrangian particle-tracking technique, a numerical model is developed to simulate the underwater transport and fate of oil spilled from deepwater. This model consists of two submodels: the plume dynamics model and advection–diffusion model. The former is used to simulate the stages dominated by initial jet momentum and plume buoyancy of the spilled oil while the latter is used to simulate the stage dominated by ambient current and turbulence. The model validity is verified through comparing model predictions with data observed from a field experiment. The model is applied to simulating a hypothetical oil spill taking place at the seabed of a deepwater oil/gas field in the South China Sea, wherein the fate of spilled oil within the first 48 h after spill starts is investigated in terms of the oil budget and its underwater distribution.