After many years of waterflooding, PⅠ2-3 reservoirs has been in the stage of extrahigh water cut, by 2016, comprehensive water cut in the study area is 92.5%.Based on wateredout log interpretation results and sealed coring data, application of numerical The remaining oil distribution law was studied by numerical simulation method, The results show that the comprehensive recovery degree of the study area is 43.02%, and the residual oil is mainly distributed in the channel sand, which still has the potential of polymer flooding. Through the field test data analysis and laboratory experiments show that the injection of the earlier opportunity, the more favorable and enhanced oil recovery. Finally, on the basis of geological modeling and numerical simulation, the study of well pattern adaptability is carried out and the reasonable injection-production well spacing is determined.