Seismic Geomorphology Of Yinggehai Formation In Dongfang X Area

The Dongfang X area of Yinggehai Basin has great prospects for oil and gas exploration.Previous studies mostly focused on the Huangliu Formation,but relatively few on the Yinggehai Formation.Because of the existence of flexural slope break zone and active diapirism,the sedimentary environment in Dongfang X area is unique and complex.In view of the characteristics of few offshore drilling areas and large areas,based on three-dimensional seismic data,log data and related literature in the study area,and using the method of seismic geomorphology,the sedimentary geomorphology of Yinggehai Formation in Dongfang X area of Yinggehai Basin is identified in detail,which can supplement the stratigraphic study of Yinggehai Formation to a certain extent..The target bed in the study area were deposited in the period of T28-T27 in the second member of Yinggehai Formation.On the basis of paleotopographic restoration,they are divided into early and late periods.In the early stage,the topography is high and low in the northwest and southeast,while in the late stage,the middle depression is gradually healed by sediment filling,showing the characteristics of high in the northwest and low in the southeast.In the early stage of T28-T27 of Yinggehai Formation in the study area,gravity flow deposits were mainly developed,and turbidite channel lateral accretion packages were a research focus in this paper.The difference of apparent curvature of channel side-product complexes can be divided into two types: low-curvature channel lateral accretion packages and high-curvature channel lateral accretion packages,which show different characteristics in seismic profiles and time slices of coherence bodies.In the late period of T28-T27 of Yinggehai Formation in the study area,delta deposits were mainly developed,and delta front subfacies were mainly developed in the underwater environment.The delta precursor has a typical precursor reflection structure in the paraprovenance seismic profile,and there are great differences between the internal and surface reflection structures.Combining seismic facies,logging facies and some core data,it is found that the formation T28-T27 in the second member of Yinggehai Formation has good exploration prospects.