The basic reservoir physical parameters of Silurian shale samples in Sichuan Basin including total organic carbon

clay mineral content and vitrinite reflectance were represented.Pore structure was characterized by field emission scanning electron microscope and low temperature nitrogen adsorption methods.Based on these characterizations

shale samples have well-developed pore structure

with micropores predominantly comprising the pore structure.It is also found that the micropore is the major contributor to the overall specific surface area

whereas most of the pore volume is occupied by mesopores.The adsorption capacity of pure methane and carbon dioxide were performed using a setup of the manometric method.The factors affecting the adsorption capacity of shale gas were investigated

and the selectivity of CO2/CH4 adsorption on shale samples was studied.The results show that the adsorption capacity of CO2 on shale is higher than that of CH4.TOC and pore structure have a great influence on shale adsorption

which is positively correlated.Meantime

a high temperature is unfavorable to shale gas adsorption and the influence of unit pressure on the adsorption decreases with the increase of pressure.In the study of competitive adsorption

shale has higher selectivity to CO2.