Research On Sedimentary Microfacies Of 3D Area In Dalianhe Grope, Tangyuan Fault Depression In Yishu Graben

In this paper,combining test analysis data , we identified and divided every sequence unit by using theory of sedimentology and sequence stratigraphy , and established high precision sequence formation frame; then concluded plane distribution regular on the basis of the research of sedimentary microfacies of Dalianhe group, so we can evaluate beneficial sand body. We analyzed possible oil reservoir type existence, and obtained oil agglomerate rule of sequence formation frame by analyzing autochthonous exploration result and comparing with ortho-area.We established identification sign of every sequence interface of Dalianhe group on the basis of sequence stratigraphy, at the same time we made dividing and comparing for the sequence formation combining well data and seismic data and certification each other. We divided Dalianhe group into two tertiary sequences, and divided every sequence into basal level raised half cycle and trailing half cycle, then concluded unit feature of every sequence formation.We have identified three sedimentary facies- fan delta face, lake face and subsea apron face- in this area, and further divided nine subfacies and seventeen microfacies; we made analysis of panel display feature of every segment by researching seismic face and predicting sand body. Region of interest mainly developed fan delta-lake depositional system which direction of material supply is east-west, central uplift belt developed fan delta- meare depositional system, and lateral depressed area developed half abyss- subsea apron depositional system.We find that sand body of beach dam of lakes and subsea apron are main saving sand body by comparing with Fangzheng fault which has the same geostructure unit as Tangyuan fault and Moliqing fault which located in southern part of Yingtong graben. Hydrocarbon reservoir type we should explore mainly are: stratigraphic onlap hydrocarbon reservoir ascribed beach dam of lakes, updip pinchout hydrocarbon reservoir and lenticular hydrocarbon reservoir ascribed underwater gravity current. The main target of exploration activity is gentle slope edge , sand body of beach dam of lakes of palecentral uplift belt southern area, and subsea apron sand body of main control fault.