Gas-bearing influential factors and evaluation of shale gas reservoir: A case study of Paleozoic shale gas reservoir in Upper Yangtze region

Shale gas reservoirs are self-generated and self-contained, and gas-bearing property should be focused on during reservoir evaluation. Based on test data of core samples from 7 wells of Paleozoic in the Upper Yangtze Platform, beginning with gas content, the influential factors for gas-bearing property were discussed, including TOC, Ro, porosity, isothermal adsorption data, illite/ smectite formation content and movable fluid percentage. It was discovered that taking 0.5 m³/t as the boundary between reservoir and non-reservoir was practicable, and each parameter appears its relationship to total gas content. Based on grey relational theory, reservoir evaluation was performed. Referring to previous results and empirical data, reservoir evaluation scheme and space image characteristics were accomplished.