Sedimentary Characteristics of Denglouku third member in the south of Shuangcheng area, Songliao Basin

Abstract

Based on sedimentary theory and high-resolution sequence stratigraphic theory, Denglouku third member in the south of Shuangcheng area is finely divided into a long-term reference surface cycle, 3 medium-term reference surface cycles and 20 short-term reference surface cycles. Denglouku third member is divided into three sand groups from top to bottom according to the medium-term reference surface cycles, and 6 layers, 6 layers, 8 layers in the groups respectively. Through fine observation of rock cores and data analysis of nearly one hundred wells, it is believed that alluvial fan facies, fluvial facies and delta facies are developed in the study area, which can be further divided into 6 subfacies and 12 microfacies. After the analysis to the plane distribution and vertical evolution characteristics of sedimentary facies, it is found that Denglouku third member in the south of Shuangcheng area shows a water-transgression sedimentary cycle from bottom to top which reflects the sedimentary process of water body gradually deepening.