developing a compositional reservoir model for investigating the effect of interfacial tension on oil recovery

in this paper, a simplified formulation for compositional reservoir simulator is presented. these types of simulators are used when inter-phase mass transfer depends on phase composition as well as pressure. the procedure for solving compositional model equations is completely described. for equilibrium calculation, property estimation peng robinson equation of state is used. this equation was tuned using some data from swelling test and saturation pressure data.  it is another purpose of this work, to show how the gas oil interfacial tension impresses the predictions of developed compositional model. application of the simulator to simulate the results of oil recovery from displacement tests is presented. a good agreement was achieved between the experimental data and model predictions.