Predicting the state and properties of Deepwater Horizon oil under pressure using the Peng-Robinson equation of state

Being able to estimate the partitioning behavior of the live oil mixture between a gas and a hydrocarbon liquid phase is crucial for valid modeling of the behavior of the emitted fluid. Equations of state are a well-known way to estimate the phase partitioning and phase properties of real fluids under varying pressure and temperature conditions. We used the Peng-Robinson equation of state in combination with the Lin-Duan volume translation to predict the phase partitioning and phase densities of the emitted fluid at pressures and temperatures corresponding to Gulf of Mexico water column depths ranging from 0 to 1500 m. We modeled the emitted fluid based on the 148 compounds quantified on an individual basis by Reddy et al. (2012), together with 131 pseudo-components derived from comprehensive two-dimensional gas chromatography with a flame ionization detector and simulated distillation data for the thousands of compounds not measured on an individual basis. Several correlation methods were used to estimate the required properties, when data were unavailable. The predicted density of the dead oil at surface conditions matches the measured density within