Evaluation Of Development Effect And Research On Governance Countermeasures Of C5–C5B Block

C5-C5B block belongs to Chaoyanggou oilfield,which is a low permeability fractured reservoir.From 1986 to the end of 2020,the comprehensive water content of the block was71.07%,and the recovery degree was 27.49%.At present,it has entered the middle and high water cut period,and the water cut rises rapidly.It is necessary to evaluate its development response,analyze its remaining oil distribution at present,and study and judge the next step of treatment measures for the exposed problems to achieve the purpose of controlling water and increasing production.Based on the industrial standards and the actual development situation of Chaoyanggou Oilfield,this paper uses the multi-level average method to formulate the standard of the first class of blocks,and determines that the C5-C5B block is in the state of not reaching the standard.Then,the development index of each well area in the study block is judged to reach the standard.The development effect is evaluated one by one,and the problems existing in the current development are pointed out,which lays the foundation for the formulation of the subsequent adjustment scheme.The geological modeling and numerical simulation software are used to simulate the research block,and the model is optimized by combining the equivalent simulation of matrix starting pressure gradient and the simulation method of fracture pressure sensitivity effect.The distribution characteristics of remaining oil in the plane and longitudinal of each well area are studied,and the remaining oil type in the plane and its proportion in various types of oil layers and the remaining oil production in the longitudinal are clarified.At present,incomplete injection-production and planar interference residual oil are the main types of uninfilled well areas.the primary encryption area is mainly plane interference and fault occlusion;the proportion of remaining oil with inter-layer interference in the secondary encryption area increases significantly.Vertically,with the encryption of well pattern,Remaining oil in type II and III reservoirs is gradually used but there are still remaining oil.According to the above characteristics of remaining oil,the countermeasures for remaining oil control are further determined.Combining the development problems in different well areas with the remaining oil distribution characteristics,the remaining oil control countermeasures in each well area are studied and determined.The development effect is compared and predicted by numerical simulation software,and the remaining oil control countermeasures in different well areas are optimized.Horizontal sidetracking drilling is suitable for remaining oil tapping in uninfilled well area.It is predicted that the recovery degree is increased by 0.81%and the cumulative oil increment is 5.62×10~4 t in ten years.The secondary encryption method is used for remaining oil tapping in the first encryption well area,and it is predicted that the recovery degree will increase by 1.94%and the cumulative oil increment will be 7.62×10~4t in ten years.Deep profile control method is used in secondary infill well area for remaining oil tapping in ten years.It is predicted that the recovery degree is increased by 2.38%and the cumulative oil increment is 7.79×10~4t.After the implementation of the scheme,the recovery ratios of the unencrypted area,the first-encrypted area and the second-encrypted area increased by 3.66%,3.54%and3.15%,respectively,and the average increase of the block was 3.51%.