Sedimentary Fades of the First Member of Huoshiling Formation in Changling Fault Depression

The study of sedimentary facies has been conducted for the first member of Huoshiling Formation of Dongling Area, Changling Fault Depression, and the south of Songliao Basin with coring, logging and seismic data. It is believed that fan delta facies and lacustrine face are well developed in the first member of Huoshiling Formation, of which fan delta facies can be subdivided into delta plain and delta front subfacies. The delta plain subfacies consists of braided channel and interdistributary channel microfacies. The delta front subfacies consists of under water distributary channel, interdistributary bay, mouth bar, distalbar and front sheet sand microfacies. The lacustrine facies can be subdivided into semi-deep lacustrine and deep lacustrine subfacies. Through study on sedimentary facies distribution of the first member of Huoshiling Formation, it is concluded that the sand bodies are mainly distributed in the Huo-Ⅱ and Huo-Ⅲ sand group, secondly in Huo-Ⅰ sand group and Huo-Ⅳ sand group in the first member of Huoshiling Formation.