Impact of Capillary Pressure on Numerical Simulation of Immiscible Water-Alternating-Gas (IWAG) Injection

IWAG is extensively used as an enhanced oil recovery method worldwide with diverse extent of success. IWAG simulations normally do not incorporate capillary pressure effect. This parameter is always neglected due to unavailability of reliable measured data or the assumption of insignificant effect. However, former studies indicate that capillary pressure is important in porous media flow description because of the saturation distribution in the capillary-like pore spaces. The aim of this project is to investigate the impact of three-phase capillary pressure on the field oil recovery, water cut and oil relative permeability of IWAG injection process at different water-oil mobility ratio. The study involves fully penetrating wells, vertical injection and production wells in a three-dimensional oil reservoir which is homogeneous, isotropic, and with uniform thickness. To examine the effect of three-phase capillary pressure, the injection rate is varied from low to high. The finding of this study shows that three-phase capillary pressure has significant impact in IWAG simulation process.