摘要
Biological shale gas is an essential type of shale gas.It has the characteristics of shallow burial depth and large area.According to the analysis of the depositional environment,the structural setting and the geochemical characteristics of Es1 Member shale in Yangxin Subsag,this paper points out that the Es1 Member source rock has the favorable conditions generating biological shale gas.The Es1 Member shale is high quality source rock with large thickness and area.The depth of Es1 Member source rock is from 1,200 to 1,800 m,temperature is from 54.0 to 63.0 ℃.Source rock is in biogenic gas hydrocarbon generation peak period.Es1 Member has the characteristics of rapid deposition and salty lake basin,which provides favorable preservation condition and hydrocarbon-generation condition.The biological shale gas generated from source rock accumulates nearby,showing the typical insitu accumulation mode.The middle area with large abnormal value in Yangxin Subsag is the favorable development zone of biological shale gas.