Improving Mobility Ratio Vs Dealing with Fracture for Sweep Improvement with CO2 Floodin

CO2 has been used effectively in Enhanced Oil Recovery (EOR) processes to improve displacement of the residual oil. However, EOR in fractured reservoirs has always been a challenge for the petroleum industry. The presence of fractures provides an easier flow path between injection and production wells for injected fluids often causing early breakthrough thereby affecting the flooding process. The application of CO2 EOR processes in these reservoirs is hence strongly dependent on the fluid flow in the fracture and matrix zones.;The purpose of this study is to answer the crucial question in CO 2 EOR methods of whether to improve the mobility ratio or deal with the fractures for effective sweep improvement. This was evaluated by examining the relative importance of flow capacities in matrix and fracture zones. The variation in flow capacity ratio of matrix and fracture with respect to fracture width provided insights into the aspect of flow distribution.;Using analytical calculations, a criterion was established to evaluate the flow into matrix and fracture zones. Based on this for a fractured reservoir (depending on its fracture width) an informed decision can be made regarding the type of above mentioned treatments to be undertaken to improve the CO2 sweep efficiency.