Laboratory Test Study On Improving Waterflooding Development Effect In Cheng Bei Oilfield

The geological structure of Cheng Dao oilfield belongs to a typical river sedimentary facies reservoir.The reservoir has the characteristics of heterogeneity.The Cheng Dao Oilfield has experienced many years of high efficiency development.The water content of the production well is high.Due to the heterogeneity of the reservoir,the water injection is uneven.It is necessary to make adjustments to the development of the high water cut period.Since the reservoir has undergone many adjustments,The layer division and the layout of the well network are also perfect.Due to the requirement of high recovery ratio for production wells in heterogeneous high water cut stage,Therefore,it is necessary to carry out water injection development adjustment on this basis.To achieve the effect of increasing the efficiency of the night.At the same time,a reasonable injection and production plan for heterogeneous reservoirs is also explored.To achieve the maximum collection efficiency requirements.This paper focuses on physical simulation experiments.The research object is a block in the northern part of Cheng Dao oilfield.According to the actual situation of Cheng Dao Oilfield,the following experiments are designed.First of all,water sensitivity experiments on natural cores in the North block of Cheng Dao oil field are carried out.The corresponding data and charts are obtained through water sensitive speed sensitivity test.The experimental data were analyzed according to the evaluation criteria of water sensitivity.Experimental analysis shows that the sensitivity of reservoir core to water sensitivity is weak.The water sensitivity and speed sensitivity of the core are better.It provides a theoretical basis for further water flooding experiment.Secondly,double tube parallel injection experiment is carried out for interlayer heterogeneous cores.The first choice is to drive at a constant flow rate.When the water content reaches 75%,the displacement velocity is changed.When the water content reaches100%,the displacement is stopped.Charts are drawn according to the experimental results of different injection rates.Through comparative analysis,the influence of different injection rate on recovery factor is explored.The experimental results show that increasing the injection rate on the basis of the original velocity can improve the original oil recovery.Finally,the water flooding experiments of heterogeneous cores at different velocities are carried out.Experiments were carried out with different gradient velocity to conduct water flooding experiments.At the same time,the high and low permeable layers of the corewere displaced simultaneously.According to the experimental results and the influence of the seepage effect of heterogeneous cores in different flow velocities on the recovery factor,The water flooding rule and reasonable water injection plan of heterogeneous core in the process of water drive development are summarized.