An Inspection Well Data Analyzing Approach to Residual Oil Distribution After Polymer Flooding

As one of the widely applied EOR methods in China, polymer flooding can gain about 10% incremental oil recovery. Meanwhile, most producing wells have been in high water cut period, subsurface displacement is still non-uniform and some non-flushed layers also exist inside reservoirs etc. So there are still 50% residual oil reserves left after polymer flooding in reservoir. Aiming at developing the pretty high exploitation potential, it's necessary to study on residual oil distribution law after polymer flooding. For that reason, the key multi-section-and-multi-rhythm reservoir in the north of Daqing placanticline is selected at first. Then, by comparison of flushing conditions between water flooding and polymer flooding, residual oil distribution law after polymer flooding has been studied by utilizing 11 inspection wells' data. Finally, five enrichment areas residual oil existed in the reservoir have been put forward respectively. The research process and results can provide certain methodological and theoretical references on the studies on residual oil distribution, the rational adjustment and potential tapping after polymer flooding.