A Study On Sedimentary Facies In Bailian Area Of Beibuwan Basin

The Bailian sag,a middle-east part of the Fushan Sag,is developed in the Baibuwan Basin,fracture activity is very complex,and there is no unified understanding of the sand body and sedimentary rule.In this paper,we try to deepen our understanding of the distribution of sand bodies in the area by studying sedimentary microfacies,which will provide a theoretical basis for further reservoir development.Using the method of seismic,logging,core and other data to apply the method of combining well seismic geology,the target laminar sand port group is divided into five layers:ElS1-?,Else-?,Elsi-?,Elsi-? and Elsi-0.In the course of the study,according to the situation of the less drilling well position and uneven distribution about close in the middle,and the situation of vertical accretion and lateral accumulation of strata in Bailian area,accuracy of logging identification mark layer,lateral extension identification of seismic profile,large range contrast of seismic profile,and fine analysis of logging and core data are finally extended to the whole area.The seismic phase of the study area is studied by combining the geometric shape and internal reflection structure with the factors of frequency and amplitude,to identify the 5 types of seismic facies in the form of attendance,sheet,Pre-wedge product,the divergence of the wedge,and the lens like.The phase plane method is applied to draw the plane seismic facies and compared with the plane attribute map and gamma acoustic wave inversion map,we find a good match.The fan delta-lake depositional system is developed in the first stage of the first member of the Bailian area,and the fan delta front is the main sedimentary system.Further recognizes underwater distributary channel,estuary dam,distributary Bay,mat sand and slump turbidite.Gaphic layout of sedimentary facies for each sequence in L1 of Bailian area with single factor analysis and multifactor comprehensive mapping method.Finally,we summarize the plane distribution characteristics and vertical evolution characteristics of sedimentary facies in this area.The sedimentary system in the plane distributes in the long flow fault downhill disk,controlled by the eastern provenance,mainly develops fan delta,and the fan body expands unceasingly.Vertically,the depositional system gradually develops from the initial deep lake-semi deep lake to fan delta,and the fan body keeps moving westward.