Oil Well Blowout 3D computational modeling: review of methodology and environmental requirements

Abstract

This literature review aims to present the different methodologies used in the three-dimensional modeling of the hydrocarbons dispersion originated from an oil well blowout. It presents the concepts of coastal environmental sensitivity and vulnerability, their importance for prioritizing the most vulnerable areas in case of contingency, and the relevant legislation. We also discuss some limitations about the methodology currently used in environmental studies of oil drift, which considers simplification of the spill on the surface, even in the well blowout scenario. Efforts to better understand the oil and gas behavior in the water column and three-dimensional modeling of the trajectory gained strength after the Deepwater Horizon spill in 2010 in the Gulf of Mexico. The data collected and the observations made during the accident were widely used for adjustment of the models, incorporating various factors related to hydrodynamic forcing and weathering processes to which the hydrocarbons are subjected during subsurface leaks. The difficulties show to be even more challenging in the case of blowouts in deep waters, where the uncertainties are still larger. The studies addressed different variables to make adjustments of oil and gas dispersion models along the upward trajectory. Factors that exert strong influences include: speed of the subsurface currents;  gas separation from the main plume; hydrate formation, dissolution of oil and gas droplets; variations in droplet diameter; intrusion of the droplets at intermediate depths; biodegradation; and appropriate parametrization of the density, salinity and temperature profiles of water through the column.