Study On Sequence Stratigraphy And Subtle Reservoir In The South Slope Of Dongying Sag, Bohai Bay Basin

The south slope of Dongying Sag is located in the margin of basin, where tectonic activities were happened frequently, many stratigraphic denudations and overlaps were formed, and many unconformities were developed. At the same time, the origin of oil and gas is rich in study area. The oil and gas could migrate into many kinds of traps though faults, unconformities and permeable sand body. So the formation condition of stratigraphic reservoir is well.On the base of data analyses of seismic, well logging, core and geological logging, referencing the former study results and the features of basin evolvement and tectonic actives, the sequence stratigraphic frame of study area was established. The Paleogene strata of the south slope of Dongying Sag can be divided into one the first order sequences, four the second order sequences and eight the third order sequences.On the base of the sedimentary facies analyses of single well and cross section of key well, the features of sedimentary evolvement and distribution were studied in the south slope of Dongying Sag, which shows the obvious law. On the transverse orientation, the distribution of sedimentary system shows belts. The alluvial fans and fluvial facies were developed in the margin of basin. Towards the inner of basin, the delta, shoal sand body, infralittoral turbidite fan and so on were developed; on the vertical, the evolvement of sedimentary system shows obvious cyclicity, which the alluvial fans were developed in the Kongdian-1 member and the lower Shahejie-4 sub-member, the shoal sand bodies were developed in the upper Shahejie-4 sub-member, turbidite fans were developed in the lower and middle Shehejie-3 sub-member, the deltas were developed in the upper...