Study On Reservoir Heterogeneity Of The Middle Es3 Member In Block Fan 29,Daluhu Oilfield

Thin layers with various physical properties developed in the 4th sand bed of the Middle Es3 member in Block Fan 29,Daluhu Oilfield.Aiming at the reservoir characterization of such reservoirs,this study is carried on.Previous research results,drilling cores,logging,mud logging,oil well test,pilot production and dynamic production data are used to characterize the heterogeneity of sub-lacustrine fan reservoirs.Reservoir heterogeneity on plane,intralayer,and interlayer are described in details.The control of various heterogeneity on the distribution of oil and gas is analyzed carefully,The above study provides reliable geologicalbasis for revising development plan.Guided by the advanced theories,such as sequence stratigraphy and sedimentology,based on changes in sedimentary cycles,the 4th sand bed of the Middle Es3 member in Block Fan 29 is divided into single sand layers.Based on integrated interpretation of well logging,the distribution of reservoir fluid is analyzed,To the comprehensive analysis of the reservoir in profile and on plane,the control of the reservoir heterogeneity on the heterogeneous distmbution of oil and gas is further revealed in this study.On the analysis of the factors which affect the sub-lacustrine fan reservoirs,including sedimentary micro-facies reservoir properties,diagenesis,fluid and structure,and so on,comprehensive evaluation ofreservoir is carried out.Establishing the stratigraphic framework of the target area in the study area,and then dividing the 4th sand bed of the Middle Es3 into 4 small layers,each small layer is further divided into 4 sand bodies.The reservoir sand body of Block Fan 29 mainly consists of sub-lacustrine fan deposits,including sub-phase of middle fan,outer fan and lacustrine shale,with the middle fan sub-phase dom inating.the middle fan sub-phase is further subdivided into braided channel,braided channel side edge,lobular body and mid-fan lateral margin micro-phase,with the braided channel micro-phase distributing widest,which is the product of vertical accretion.Characterized by the middle porosity and low permeability,reservoirs in Block Fan 29 have strong heterogeneity within inner layers and interlayers on the microscopies seale in the plane.The 43 single layers has relatively good physical due to its relatively weak heterogeneity,and thus serves as the main reservoir.It is found that sedimentology,diagene,sis and tectonic commonly contribute to the reservoir heterogeneity in Block Fan 29,among which sedimentology plays the main role.In terms of diagenesis,compaction and cementation deteriorate the physical of reservoir,while dissolution improves them.Natural fractures produced by tectonism have dual effects on reservoir physical properties.According to the heterogeneity index,the reservoir is divided into four types(?,?,?,?),The reservoir types of the 42,44 and 45 small reservoirs are mainly composed of type ? reservoirs and type ? reservoirs,which have strong reservoir heterogeneity.The reservoir types of the 43 small reservoirs is mainly composed of type ?reservoirs and type ? reservoirs.