Effect of subsea dispersant application on deepwater oil spill in the South China Sea

There are considerable amounts of offshore oil/gas fields in the South China Sea (SCS), and for potential oil spill events in this area, dispersants may provide a reliable large-scale response when the preferable option of recapturing the oil cannot be achieved. In this paper, effect of chemical dispersants on underwater oil transport is investigated with an underwater oil spill model. Since the model is an adaption of an existing one, we first calibrate it by comparing the model result with echo-sounder data that were observed during the "DeepSpill" experiment with crude oil/LNG (liquefied natural gas) discharge. Then, with the hydrodynamic data provided by an operational forecasting system and the drilling data obtained from offshore platforms in the SCS, we apply the model to a hypothetical spill case, and examine the difference in oil distribution in water column caused by subsea dispersant application. The model results can provide valuable reference for contingency plan makers to make an efficient emergency response to potential underwater oil spill accidents in the SCS.