Research on identification method of dominant seepage channels after polymer flooding-a case study of Block X in Daqing Oilfield
Due to low efficiency circulation of injected liquid along the dominant seepage flow in the late pol-ymer flooding period,the water cut will rise too fast if injected polymer solution continues,which will affect the oilfield development effect and economic benefit.The evaluation system of the dominant seepage chan-nels after polymer flooding was established by the cumulative probability method,and the weight of each system was evaluated by the gray correlation analysis method.The classification limit standard of the domi-nant seepage channels was established.The method was applied to Block X of Daqing Oilfield,and the wa-ter-flooding ratio of each sedimentary unit was defined.The identified superior seepage channels were veri-fied by the stratified water absorption data of water injection wells,which provided guidance for the treat-ment of superior seepage channels in the later stage.