Minimum miscibility pressure calculations including effects of three phase equilibria

This work presents the first equation-of-state (EOS) algorithm to compute minimum miscibility pressures (MMP) in hydrocarbon systems exhibiting three-phase (L-L-V) equilibria. Previous efforts have been limited to systems involving only two-phase equilibria. This work is particularly applicable to low-temperature reservoirs since they often exhibit L-L-V phase behavior. A comparison of twoand three-phase algorithrn results shows that the two-phase algorithm may overpredict the MMP in cases where three-phase equilibria is realized. The results of a CO2 - West Texas oil system show that the error by the two-phase algorithm is significant and the three-phase algorithm offered here should be used.