Controlling factors of marine shale gas differential enrichment in southern China

JIANG Zhenxue,SONG Yan,TANG Xianglu,LI Zhuo,WANG Xingmeng,WANG Guozhen,XUE Zixin,LI Xin,ZHANG Kun,CHANG Jiaqi,QIU Hengyuan

Table 1 The main characteristics of the shale in the Xiamaling Formation and the Wufeng-Longmaxi Formation.

Basin/Region Formation Sedimentary environment Maturity/ % TOC/% Organic matter type Maceral Mineral composition Xiahuayuan area, north China Xiamaling Formation Marine 0.67 2.9-6.64 I—II1 Mainly sapropel group, with little exinite Mainly quartz and andreattite Sichuan Basin and its periphery Wufeng-Longmaxi Formation Marine >2.0 1.23-4.71 I—II1 Mainly sapropel group Mainly quartz and illite