Sedimentary characteristics of the second member of the Kongdian Formation in the Weibei depression, Shandong

The present paper gives a detailed description of the stratigraphic characteristics and sedimentary evolution of the second member of the Kongdian Formation in the Weibei depression,Shandong in the light of cores, well logs and seismic data. The second member of the Kongdian Formation in the Weibei depression consists of two medium-term and nine short-term depositional cycles, and is made up of the fan delta facies, nearshore submarine fan facies and lake facies. The study area went through the shallowing-upward and then deepening-upward evolutionary processes, and may serve as good sites with excellent source-reservoir-seal associations favourable for the hydrocarbon accumulation and preservation. The fan delta front subaqueous distributary channel, turbidite fan and beach-bar sandstones are interpreted as favourable reservoir rocks in the study area.