Study On Sequence Stratigraphy And Sedimentary Facies Of The Lower Member Of Shasan(Es3x) In Xianhe Area Of Dongying Depression

This paper studies on the sequence stratigraphic frame, the characters of facies marks, facies types and distribution rules of facies by the relevant data of cores, well-log and seismic data on the basis of sequence stratigraphy and sedimentary.Under the guide of the theory of sequence stratigraphy and using the ?log method and the Toatal Organic Carbon(TOC) method combining the sedimentary characters and the seismic data, the sequence boundries and 7 parasequences are recognized in the lower member of Shasan. The lower member of Shasan(Es3) is divided into a 3rd order sequence which contains 7 parasequeces by the examination and correlation of the well-log and seismic data. The top boundary of the sequence is corresponding to the T6'seismic reflection, and the bottom is corresponding to the T6 seismic reflection. The TST is composed of parasequence1 to parasequence 7, and the RST is composed of paresequence 5 to para-sequence 7. The maximum flooding surface which is composed of black oil shale and gray mudstone and lime-mudstone occurred in the parasequence 4.There are delta facies, near-source slump turbidite fan, distal slump turbidite fan, flood water turbidite fan and beach bar recognized in the lower member of Shasan(Es) by the relevant data such as cores, well-log data, log data and geochemistry data. And the delta front sand, slump turbidite fan and flood water turbidite fan are the main reservoir bodies. The distribution of sand displays the different characters in plane. The near-source slump turbidite fan, distal turbidite fan and flood water turbidite fan only occur in the central and northern region of interest, and the delta sediment and beach bar occur in the southern region. There are a lot of NNE-ward water channels in the region of interest. The near-source turbidite fans, distal turbidite fans and flood water turbidite fans occur in these water channels or near these channels. In other positionsThe research on the sediment evolution was conducted in the sequence stratigraphic frame. The distribution of sandstone was controlled by the sequence evolution. There were two turbidity flow peaks in the early RST and TST, and the delta facies only occurred in the RST. And the distribution area of delta facies had become larger and larger as the water level declined and the sediment supply was reinforced.