New EOR Technology: Simultaneous Gas Alternating Gas (SGAG) injection

Abstract

A new oil recovery method known as Simultaneous Gas Alternating Gas (SGAG) injection that is based on the principle of the conventional Simultaneous Water Alternating Gas (SWAG) injection has been proposed in this study. The performance was observed via a simulation process based on data from an oil field of a shale oil reservoir. The effectiveness of SGAG was evaluated through a sensitivity analysis, and by observing its effect on oil recovery factor and ultimate oil recovery. The results of the sensitivity analysis show that (1) SGAG technique will improve the ultimate recovery factor compared to continuous gas injection; (2) Based on gravity segregation between two gases, oil recovery is enhanced; and (3) Because the produced CH4 can be reinjected and based on the availability of CO2, the possible SGAG combination of (CH4 + CO2) is more economically and feasible for a tank of Shale Oil reserve. This study provides a reliable basis for minimizing operating costs per unit CO2 injection volume and insight into cost-effectively enhanced oil recovery (EOR) technique.