Research On Sedimentary Microfacies Of Fang4 Well Area In Cretaceous And Paleogene, Fangzheng Fault Depression

Combining all kinds of 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 of the Fang 4 area on the basis of the research of sedimentary microfacies of Cretaceous and Paleogene, 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 Cretaceous and Paleogene 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 Cretaceous and Paleogene into ten 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 sublacustrine fan- in this area, and further divided 8 subfacies and 16 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 north and the Yihantong in the south.