A Method for Enhancing Oil Recovery by Producing Remaining oil at Fluid Diversion Line at Subsequent Water Flooding Stage after Post-polymer flooding

According to hydrodynamic flow field distribution theory,a new method is provided for enhancing oil recovery,by adjusting water flooding regime and adding polymer near fluid diversion line to produce remaining oil.Prediction research is done by numerical simulation for the method.It is indicated from results that,after injecting polymer solution with normal concentration of 640mg/L·PV,additional polymer solution with concentration of 300mg/L·PV is injected through conversion wells.Thus recovery rate is increased by 4.21%,which has an obvious effect.