High-resolution sequence stratigraphy and sedimentary facies evolution of the upper submember of the 4th member of the Shahejie Formation on the southern slope of the Dongying depression,Shandong

The oil measures and oil pools occur as a composite oil and gas accumulation zone on the southern slope of the Dongying depression,where the upper submember of the 4th member of the Shahejie Formation is believed to be one of the main target members,and may be divided into seven short-term cycles and two mid-term cycles on the basis of lithological and electrical data.The sequence stratigraphic correlation in well-tie sections made it possible to construct the regional stratigraphic framework and examine the spatial distribution of the beach and bar sand bodies and sedimentary facies evolution.