Modeling of Asphaltene Precipitation in Calculation of Minimum Miscibility Pressure

Abstract

An algorithm has been developed to investigate the effect of asphaltene precipitation on calculation of minimum miscibility pressure (MMP), which is one of the key design parameters of any gas injection projects. In fact, this algorithm is the extension of procedure suggested by Jaubert et al. for prediction of MMP whatever the displacement mechanism. The vapor–liquid equilibrium calculation and then liquid–liquid equilibrium calculation are required to be taken account to estimate the amount of asphaltene precipitation. The association equation of state (AEOS) has been applied to determine the phase behavior of asphaltene. The algorithm has been used for the MMP prediction of Weyburn reservoir oil in which the precipitation of asphaltene has been reported. The results show good agreement with those experimental data obtained by slim tube, and improved by 7.6% and 5.3% on average compared to Jaubert’s algorithm and Ahmadi’s approach, respectively.