Numerical Simulation Study Of Separate Zone Injection And Production For EOR In Beierxi Block Of Saertu Oilfield

Daqing Oilfield is a supergiant heterogeneous and multilayered sandstone reservoir which has 80~120 subzones, and its interlayer permeability contrast is up to 60 times more. Bererxi Block has entered extra-high water cut period after 40 years development. The composite water cut reaches 93.46 percent and the degree of geologic reserve recovery reaches 38.98 percent. There is still a great quantity of residual oil left underground. Development experiences indicate the remaining oil distributed in the top of the thick layer and poor layer in different scale and different forms. Separate zone injection and production can tap this type remaining oil, which is conducted by injecting separated in the injection end while producing from individual layer. It is aimed at increasing the productivity of weak water flooding zones or parts and controlling the produced fluid intensity in high water flooding zones. Separate zone injection and production technology can control the water cut, production decline and improve invalid water circulation. This technique is one of the main methodes to achieve "oil stablization and water control" policy and enhance oil recovery.This paper analyses the filtration theory of separate zone injection and production intensively. Combined with Beierxi block developing character, concept model is built to study the separate zone injection and production affecting factors, such as barrier bed, rhythmicity and reservior pressure. Besides, the fine geologic and dynamic production models of the testing block in Bererxi were are established, and history matching of the water and polymer flooding is carried out to verify the models. The best Separate zone injection and production project and rational production system are optimized by the forecasted results of separate zone injection and production effects.The results show that the separate zone injection and production project increased injection pressure and controlled the produced fluid intensity excavated the potential of the residual oil utmostly.This paper has a certain academic value and theoretical significance. It provides technical support for the further tapping of the remainding oil and the development adjustment in Bererxi block, and also provides a theoretical basis for injection-production adjustment of the same oilfield in the late development period.