The sedimentary characteristics and hydrocarbon potential of Meso-Neoproterozoic source rocks in North China Platform

With the continuous discoveries of commercial Proterozoic primary reservoirs in recent years, Proterozoic strata have gradually become the focus of oil and gas exploration. Yanshan area of North China Platform is one of the most developed regions of the Meso-Neoproterozoic stratum in China, and the thickness of the Meso-Neoproterozoic can reach 9553 m. Although oil and gas shows such as oil seedlings were discovered long ago, the exploration breakthrough of oil and gas has not been made so far. In order to carry out targeted oil and gas investigation and exploration, it is of great significance to select the favorable source rock for oil and gas exploration from the Meso-Neoproterozoic sedimentary strata. Based on the analysis of sedimentary characteristics of dark mudstone and microbial carbonate rocks of Meso-Proterozoic in North China Platform, the hydrocarbon generating potential was preliminarily evaluated. The average values of TOC for thick dark mudstones or shales developed in Chuanliggou Formation, Honghongzhuang Formation and Xiamaling Formation are 0.89%, 2.54% and 2.82%, respectively, and the average values of Ro are 2.03%, 1.05% and 0.63%, respectively. Microbial carbonate rocks are widely developed in Gaoyuzhuang Formation, Wumishan Formation and Tieling Formation, rich in microbial community and other organic matter residues, in which high quality source rock with TOC > 0.2% are developed.