Evaluation and comparison of different EOR techniques after polymer flooding

The results of different chemical oil displacement forms after polymer flooding and their EOR mechanisms are studied by physical simulation.The remaining oil saturation of the physical model is monitored in the simulation experiments.The results demonstrate that,the oil recovery factor could further be enhanced after polymer flooding by combining well pattern infilling with chemical flooding.Of several simulated chemical flooding forms,ASP compound system has the best oil displacement result,and it can further enhance oil recovery by 17.2%.The analysis of the remaining oil saturation distribution shows that,the mechanism to enhance oil recovery in low permeability reservoirs is to expand sweeping volume in high permeability layers is to improve oil displacement efficiency.Therefore,two mechanisms to enhance oil recovery should be considered in the selection of the water flooding forms after polymer flooding.