Study On The Adjustment Technology Of The Development Scheme Of Combination Of Two And Three In Block X

After more than 50 years of water injection development,block X has entered the later stage of high water cut,with less recoverable reserves and serious reservoir heterogeneity,making subsequent mining more difficult.In this context,conventional water flooding development has been unable to meet the requirements of enhanced oil recovery in the target area,and tertiary oil recovery technology has been put on the agenda.Petrochina in 2012 proposed the "overall control,formation breakdown,plane restructuring,three-dimensional optimization,deep displacement,two series" technical route,from "to improve water injection,water injection,change displacement medium" three aspects of continuous deepening secondary development engineering,initially formed the old oil field to improve the water flooding effect and improve the recovery efficiency of the combination of technology roadmap,Clearly put forward the "combination of two and three" as the strategic choice of sustainable development of old oil fields.In this paper,combined with the actual situation of X block,the application of numerical simulation technology,the establishment of three-dimensional geological model and numerical simulation model,the main production dynamic parameters of the historical fitting,on the basis of historical fitting,the remaining oil distribution characteristics are studied,divided into the main remaining oil types in X block.The distribution law of remaining oil is further recognized and the starting mechanism of different types of remaining oil and corresponding using measures are given.In order to improve the injection-production effect,increase the water flooding control reserves,and advance the tertiary oil recovery in an orderly manner,a well pattern reconstruction scheme for the combination of two and three was formulated,and grey correlation and cluster analysis were used to reclassify the original layers.According to the shape of reservoir sand body,the numerical model is established to optimize the best well distribution mode under different shape sand body,and the reasonable well pattern and well spacing is calculated by using serkachev formula which introduces economic evaluation.In X block,binary composite flooding was selected for tertiary oil recovery.Numerical simulation method was used to screen out appropriate injection parameters for the composite system.The recommended comprehensive water cut of the two-three combination in X block was 94%,and the polymer concentration was 1500mg/L,surfactant concentration was 0.3%,total injection volume was 0.7PV,and injection speed was0.12PV/a.For eor,a single slug of 1500mg/L(P)+0.3%(S)was selected,resulting in an eor of12.88%.At the same time,five plans are designed for block X,and a comparative study is conducted on the five development plans.It is concluded that the fifth plan with infill well pattern chemical flooding divided into four layers has the best development effect,with an estimated oil increase of 165.95 tons,enhanced recovery factor of 14.91%,net present value of 3.214 billion yuan and internal rate of return of 14.24% at 100 USD/barrel crude oil price.The investment return period is 4.8 years,which verifies the feasibility of implementing the two-three combined development mode in AREA X.