Sedimentary Sequence Of Cretaceous Kapushaliang Group In Yingmali-halahatang Area,Northern Tarim Basin

Based on 3D seismic,logging,core and outcrop data,this paper studies the sequence stratigraphy and sedimentary system of the Cretaceous Kapushaliang Group in Yingmaili Halahatang area,northern Tarim Basin,establishes the sequence correlation framework of the Kapushaliang Group in Yingmaili Halahatang area,and identifies the main types of sedimentary systems,The horizontal distribution characteristics and vertical evolution process of sedimentary system under sequence framework are analyzed.In addition,based on the understanding of regional research,high-resolution sequence stratigraphy is carried out for the oil and gas bearing intervals in the key areas to find out the sedimentary facies distribution and vertical evolution law under the high-resolution sequence framework,and reveal the favorable exploration direction in the area,so as to provide reference for the subsequent progressive exploration of clastic rocks in the study area.According to the theory of sequence stratigraphy,the Kapushaliang Group in the Yingmaili Halahatang area is divided into a second-order sequence,and two second-order sequence boundaries(tk1bs and TK)are identified at the top and bottom of the Kapushaliang Group;According to the stratigraphic superimposition style transition interface and sedimentary facies type transition interface,it can be divided into five third-order sequences SQ1,SQ2,SQ3,sq4 and SQ5,and the sequence comparison framework of Kapushaliang Group in Yingmaili Halahatang area of northern Tarim Basin is established by fine tracking and correlation under the well seismic calibration.Under the guidance of sedimentology theory,combined with core observation,logging facies analysis and field outcrop investigation,it is considered that Braided River Delta,shallow water delta and beach bar are the main sedimentary systems in the study area.Based on the study of lithofacies type and combination,logging facies,the sedimentary characteristics of each sedimentary system are summarized,the plane distribution of sedimentary system in each sequence development period is systematically analyzed,and the vertical sedimentary evolution of sedimentary system is revealed.Based on the high-resolution sequence stratigraphy theory,two third-order sequences SQ1 and SQ2,five fourth-order sequences ssq1,ssq2,ssq3,ssq4 and ssq5 and several fifth-order sequences were identified by integrating qualitative sequence division and quantitative logging wavelet transform,and the high-resolution sequence correlation framework was constructed.Combined with the understanding of regional sedimentary facies,the distribution law and vertical evolution of sedimentary microfacies under the high-resolution sequence framework are analyzed.Combined with the analysis of favorable reservoir characteristics and reservoir cap combination,the favorable exploration direction of the area is revealed.