Water Intrusion Mechanism And Application Of Bottom Water Heavy Oil Reservoir In Block F Of Sudan Oilfield

Block F of S Oilfield is a bottom-water heavy oil reservoir.Controlling excessive water production is one of the key challenges.A good evaluation of the type of water production and water invasion mechanism can provide a useful basis for the water control measures and the design of the development plan.The Chan diagnostic plots is one of the most effective methods to study the type of water produced by the water-oil ratio and its derivative.It can diagnostic the water comes from water coning or interlayer channeling.However,the method is obtained through a conceptual model,lacks theoretical derivation and more field data for verification,and does not consider behind-the-casing crossflows.It takes the F block of S oilfield as the research object,and conducts research on behind-the-casing crossflows,water intrusion mechanism,and adjustment plans through the establishment of physical and mathematical models,diagnostic plots and numerical simulation methods.This paper has completed the supplementation of diagnostic plots of behind-the-casing crossflows,assessed water intrusion mechanism,and designed a reasonable adjustment plan.A physical model of behind-the-casing crossflows is established through reasonable simplifications and assumptions.Through rigorous deduction,obtain the characteristic curve of the water-oil ratio and its derivative,and finally verified by an example.It is feasible to use the virtual well technology to study behind-the-casing crossflows.The numerical simulation model of block F is established through the Builder module of CMG.Through the START simulator,the historical fitting of each indicator of block F is completed.Because traditional methods cannot fit FMC-10 wells with behind-the-casing crossflows,virtual wells technology are used.the occurrence time,location and the water volume of behind-the-casing crossflows are obtained.The diagnostic plot of behind-the-casing crossflows is obtained through the numerical model.Then it combined with mathematical model and the Chan diagnostic plots to judge the water invasion types of 12 wells.The results of the mathematical model,numerical simulation and actual data of casing flow are basically consistent.On the basis of the numerical model,the distribution characteristics of the remaining oil in the horizontal and vertical directions are obtained by analyzing the change law of oil saturation.this article mainly carried out reasonable development plan design from four aspects: fluid production rate,interlayer adjustment,new well addition,and thermal recovery technology.