Study On Dynamic-static Combining Method To Predict Interwell Interlayer Distribution In Donghe Sandstone Reservoir Of Hudson Oilfield

Interlayer is one of the crucial geological factors that affect fluid flow,and the key element that controls remaining oil,which determines the effect of oilfield development.Currently,Hudson oilfield has entered middle-late phase of development,with some wells reaching high water cut phase,and high water bearing zone appearing around the edges of reservoir and injection wells.Besides,serious reservoir heterogeneity caused by interlayer development has become the dominating influence factor on fluid flow rules.In this thesis,the main research objects are interlayers of the Donghe SandstoneReservoir,Hudson Oilfield.Constraint by the “downlap-toplap” depositional model and considering the sedimentary geological background that sand bodies are obliquely superimposed in the seaward direction,this study identifies interlayer types,thickness,grades and occurrence based on the static geological data such as core data and well logging data.Then dynamic production data including dynamic production curves,static pressure of bottom hole,perforation data,tracer,and injection profiles are introduced to further quantitatively predict the interlayer distribution from single wells to injection-production well groups in the order of perforating correspondence analysis,well group effect analysis,and effective mode analysis.After that,the patterns of perforation and effect in the production well isestablished.There are 4 types of these patterns.They are corresponding perforation-effective injection,corresponding perforation-noneffective injection,non-corresponding perforation-effective injection and non-corresponding perforation-noneffective injection.And possible geological reason is identified to each pattern.Based on the analysis of the variation of daily output of injecting water,fluids,daily output of oil,and the water cut with production time,curves are classified according to morphological characteristics.Daily injection curves are divided into 4 types,and they are steady type,upstairs type,downstairs type and convex type.The daily output of fluid curves are divided into 4 types,and they are steady type,convex type,ascending type and declining type.The daily output of oil curves are divided into 3 types,and they are high yield and dropping fast type,high yield and dropping slowly type,low yield and dropping slowly type.The water cut curves are divided into 3 types too,and they are “S”type,slight convex type and rapidly rising type.Thus models of reservoirs with different types of water drives can be established in terms of the relationship between dynamic production response characteristics and interlayer distribution and continuity,which can provide a more reliable geological basis for understanding of the remaining oil distribution especially in spaces between wells and the adjustment of development plans.