Study On Formation Pressure Level And Optimization Of He50 Fault Block Reservoir In High Water Cut Period

In the process of oilfield development,if the formation pressure keeps too high,water flooding and other phenomena will occur,and injection pressure will increase,that is,increasing cost;if the formation pressure keeps too low,the production pressure difference that can drive oil flow from reservoir to bottom of production well can not be formed,or even threephase flow may be formed,which will make the flowability of formation crude oil worse.Therefore,it is of great significance to determine reasonable formation pressure for enhancing oil recovery.Based on the field data and numerical simulation method,combined with the theory of percolation mechanics,the optimum values of injection-production parameters related to maximizing the potential of the study area are determined,focusing on the influence of formation pressure on the optimum values of injection-production parameters;secondly,numerical simulation method,production fluid intensity method and injection-production system balance method are used to study the target reservoir from different angles.Reasonable formation pressure maintenance level is studied.Finally,based on numerical simulation method,reasonable injection-production ratio,reasonable formation pressure recovery mode,cycle and half-cycle ratio of each water injection development mode are optimized from various angles such as oil production and production life,and reasonable formation pressure recovery scheme suitable for the current situation of the study area is summarized.The results show that the injection-production parameters such as oil production index,fluid production index,water absorption index,reasonable injection-production well number ratio,reasonable oil production rate and reasonable formation pressure maintenance level are not fixed values,which change with the development status of oilfield.Therefore,in different stages of oilfield development,the injection-production well number ratio needs to be adjusted with the change of development stage.The reasonable formation pressure maintenance level under the existing conditions in the study area is established,and the optimum formation pressure recovery scheme suitable for the study area is put forward.