Compositional Modelling of Gas Injection into Oil Reservoirs

In this paper, a simplified formulation for compositional modeling of gas injection process into oil reservoirs is presented. Compositional models are used when interphase mass transfer depends on phase composition as well as pressure. A procedure for solving compositional model equations is completely described. Peng Robinson Equation of State is used for preparing a compositional thermodynamic program for equilibrium calculation, property estimation and pseudo component determination. The validity of this program was tested against experimental data such as swelling data and saturation pressure. Also the results of this model is compared with GEM software output. It is another purpose of this paper, to prepare an experimental apparatus for displacement of oil by injecting gas in a porous media. In each experiment, oil recoveries as a function of injected pore volume of gas were measured. Application of the developed simulator to simulate the results of oil recovery from slim tube experiments is presented.