Sedimentary characteristics and evaluation law in high-resolution sequence framework of Dongying Formation, North of Nanpu Sag

In order to make sure the sedimentary characteristic and evaluation of Dongying Formation, we quantitatively divide the sequence framework and distribution of sedimentary facies, comprehensive application the wave coefficient curve and maximum entropy spectrum analysis, on the base of sequence boundaries recognize. The result is that, there are 2 long-term and 3 mid-term cycle boundaries in Dongying Formation. We divide the Dongying Formation into 4 mid-term cycles, like MSC1, MSC2, MSC3 and MSC4. The fan delta plains and submarine fans are concentrated on the Xinanzhuang Fault, Baigezhuang Fault and Gaoliu Fault, they change to the fan delta front and shallow lake gradually, from the boundary fault to the central of Nanpu Sag. The evaluation of sedimentary in Dongying Formation is controlled by the union of fault, provenance and base level cycle. The base level is rising quickly in MSC1, the sediment are mainly conglomerate, medium sandstone, fine sandstone in fan delta plains and fan delta front. The base level rising slowly, and attain the maximum in MSC2, the sediment are mainly mudstone in shallow lake and semi-deep lake, it is the main source rocks in study area. The subsidence rate decrease in MSC3 and MSC4, and the base level began to decline, the sediment are mainly siltstone, fine sandstone in fan delta front, they are the main reservoirs and productive series in the study area.