CRITICAL-POINT CALCULATIONS FOR OIL-RESERVOIR FLUID SYSTEMS USING THE SPHCT EQUATION OF STATE

The ability for predicting the critical points of reservoir fluids using the Simplified Perturbed Hard-Chain Theory (SPHCT) equation of state proposed by Kim et al. is analyzed. The computational procedure developed by Heidemann and Khalil was used for locating the critical points in any multicomponent mixture described by this equation of state. Experimental binary vapor-liquid equilibrium data of interest in the petroleum industry have been used to evaluate the interaction coefficients in this equation for 164 binary mixtures. The performance of the SPHCT EOS to predict critical points is demonstrated on four oil reservoir fluid systems containing up to forty-eight components. Convergence to all the critical points existing in these large systems was obtained in a few iterations without any difficulty.