Optimization Of Plane Equilibrium Displacement Technology For Complex Fault Block Reservoir

In our country,most of the fault block reservoirs have entered extra high water cut stage.The problem is getting more complicated in this stage,such as the distribution of remaining oil is more fragmented,and remaining oil is not developed efficiently in the corner of the fault,so develop the remaining oil efficiently in the high water cut stage of the fault block reservoir,and achieving the balanced displacement of remaining oil has become a important problem.In order to solve these problems,this paper proposes a plane equilibrium displacement technology for complex fault block reservoir.Firstly,this paper analyzes the distribution of remaining oil in different fault block types with high water cut stage.According to the distribution characteristics of reserves abundance of remaining oil in plane,this chapter used the Christiansen uniformity coefficient to characterize the uniformity of residual oil distribution.In addition,this chapter uses numerical simulation method to analyze the influence of well-tofault distance,development stage,water injection mode and fault block type on uniformity coefficient.In this chapter,considering the geological and fluid characteristics,the method of fault block reservoir zoning is proposed.Reservoir zoning is distinguish according to fault combination,remaining reserve abundance and fluid seepage velocity.Policy limitation of corresponding zoning indices are established,and influencing factors of zoning results are analyzed.Combining with the characteristics of each district,this paper puts forward the regionalized development technology,which makes the control measures more pertinent.The economic policy limitation of vertical well infilling and sidetracking adjustment in different zones of the reservoir are determined,and the maps of the limit area and the limit remaining reserves of the zones under different oil prices are obtained.Based on the typical reservoir characteristics of fault block reservoirs,the corresponding control measures under different reservoir conditions are studied.Based on the results of numerical simulation,the reserve prediction model of each sub-area is obtained by least square method.Through the reserve prediction model and the economic policy limitation of each sub-area,the adjustment and control measures for each sub-area of fault-block reservoir are screened.The development technology suitable for each region was studied.Through stepwise regression analysis,the optimal injection timing and injection volume of oil wells in angle area are determined,and the optimal injection timing mathematical model is obtained.Combining the flow field,pressure gradient field and remaining oil distribution,the development effect of liquid extraction adjustment and alternating production of oil wells is analyzed,and the optimal adjustment scheme is obtained.The numerical simulation method is used to optimize the infill location of vertical well and the length and angle of drilling hole adjusted by sidetracking.The regionalized development technology is applied to the actual block,and the numerical model of the actual block is established and the productive history is fitted.According to the actual geological development of the reservoir,the reservoir is divided into different zones.Regarding the balanced utilization of each district as the goal,the regionalized development technology is adopted to optimize and adjust.This technology makes the recovery degree in the block increase by 3.3%,and the horizontal equilibrium utilization degree increase by 3.45%.This technology has produced great application effect.