Abstract: After entering high water cut development stage,CH2 block met the problems of developed predominant channel on the plane and vertical monolayer dart,which would lead to water flooded of some oil wells and fast rising of water cut.Therefore,the predominant channel recognition technology of E1f1 reservoir in CH2 block has been carried out.By using fuzzy comprehensive evaluation method,through moisture index characteristics study,the predominant channel is mainly pore type.According to different methods,the pore throat radius range of the predominant channel is calculated to be between 6.0~12.5μm.