A new three-dimensional effective water-flooding unit model for potential tapping of remained oil in the reservoirs with rhythmic conditions

Abstract After long-term water injection development, most of the oilfields in China have entered stage high-water cut, which has reached up to 90%. Due strong heterogeneity reservoir, more than 50% oil remains underground oilfields. Therefore, how predict distribution and content remaining quickly accurately heterogeneous reservoir become key EOR. In this paper, a new effective water-flooding unit model is established based on three-dimensional flow function, can characterize influence vertical streamline distribution. addition, two shape functions are defined oil–water two-phase characteristics an injection-production unit. The results show that lower part positive rhythm denser, leads formation dominant seepage channel with ease. However, for reverse forms upper reservoir. Besides, types reservoirs, greater permeability difference is, faster cut increases. Furthermore, under same condition, reaches 90% half year earlier anti-rhythm This study provides insight guidance development rhythmic reservoirs.