Production performance of water alternate gas injection techniques for enhanced oil recovery: effect of WAG ratio, number of WAG cycles and the type of injection gas

Abstract

Production performance of a water alternate gas injection (WAG) method has been reported for the effect of several operating parameters, such as, WAG injection cycles, viz., single cycle WAG and five-cycle WAG and the tapered WAG at the reservoir conditions of 120°C and 230 kg/cm2 for hydrocarbon gas and CO2 gas. It is observed that the number of cycles in the WAG injection process affects the recovery of oil from the core sample. It is observed that the tapering in the WAG injection process improves the recovery of oil initially in place. The observations on the effect of gases revealed that the CO2 gas with five-cycle WAG process gives higher incremental recovery than the five cycle WAG process using hydrocarbon gas. It is observed that the saturation profile of CO2 WAG injection shows the better gas saturation in the core as against the hydrocarbon gas in the WAG process.