The Single Sand Dody Research Of The PI Reservior In BP 34-28 Well Block,Songliao Basin

BP 34-28 Well Block is located in Zhaozhou County,Daqing City,Heilongjiang Province,with an area of about 4.41km~2.Its target stratum develops delta front facies which is part of the large-scale delta sedimentary system in the north.The sand body is a thin layer with thin interlayer development,the lateral phase of the sand body changes quickly,and the reservoir heterogeneity is strong.The well block is currently in the middle and late period of the development stage,and the production contradiction of"injection without production or production without injection"has become increasingly prominent.Conventional small-layer-based composite sandbody research has been difficult to meet the needs of oilfield production,especially the ensure of the single sandbody connection relationship.Therefore,it is urgently necessary to conduct a detailed study on the distribution characteristics and connectivity of single sand bodies to provide a basis for the adjustment of injection-production relationship and the optimization of development measures.The main understanding and results of the paper are as follows:(1)Based on the logging data as well as combined with the regional marker layer,the PI Reservior is divided into 6 single sand layers,which is in the order of"oil layer group-sand layer group-small layer-single sand layer".On this basis,the principle of"cycle comparison,grading controling"was followed to compare 58 wells in the whole area and establish a fine isochronous stratigraphic framework.(2)According to the investigation of sedimentary background,it is clear that the sedimentary facies of the working area is the delta front sediment,and the four types of sedimentary microfacies of underwater distributary channel,estuary dam,sheet sand and front mud are determined.Based on the analysis of pore-permeability distribution,sandstone thickness distribution and sand-ground ratio analysis,the plane distribution of the sedimentary microfacies of 6 single sand layers was determined.(3)Using the thought of sedimentation between river channels,elevation difference of top level of sand body,difference in sand body size and thickness of sand body,the sand body of the working area is recognized on flat.According to the three modes of isolated,superimposed and cut-and-stack,the single sand body is identified longitudinally.Combined with the research results of interlayer distribution and sedimentary microfacies,the plan layout of the single sand body PI22 and PI52 in the study area is compiled.(4)Based on the static data such as logging,sand thickness and injection-production dynamic data,etc.,the connectivity analysis of the single sand body between wells in the working area is is analyzed,and on this basis,measures are proposed for the main layer connected sand bodies in the study area.