Multiphase Equilibrium Characterization and Compositional Analysis in Presence of Hydrates

As one of the most important ways to reduce the greenhouse gas emission, Carbon dioxide sequestration coupled with hydrocarbon resource recovery is often economically attractive. Applying CO2 to exchange CH4 in the hydrate phase represents a growing concern in hydrate exploitation field. In order to characterize multiphase behavior in containing hydrate system, this paper constructed a multiphase flash model in presence of hydrates. The stability analysis and reformulated Richford-Rice equation solving algorithm are based on the minimization of the Gibbs free energy. The Soave–Redlich–Kwong (SRK) equation of state combined with Huron–Vidal mixing rules was applied in this model to give satisfactory prediction for polar systems. A good agreement between 61 experimental measurements and prediction values is observed, proving the reliability of this model.