Evaluation of the EOR Potential in Hydraulically Fractured Shale Oil Reservoirs by Cyclic Gas Injection

Gas flooding in fractured reservoirs may not be an effective avenue for improving oil recovery because the injected fluids could break-through to production wells via the fracture network. A cyclic injection scheme is one way to solve this problem. In this study, the authors propose to use cyclic gas injection to improve hydraulically fractured shale oil recovery. They used a simulation approach to evaluate the enhanced oil recovery (EOR) potential from cyclic gas injection. The simulation results indicate that total oil recovery can be increased up to 29% by cyclic gas injection, compared with the 6.5% recovery from the primary depletion. If a higher pressure is used to reach fully miscibility with reservoir oil and more cycles are employed, more oil recovery is expected.