Experimental investigation of main controls to methane adsorption in clay-rich rocks

► The difference in clay mineral type is one key element controlling CH4 adsorption in clay-rich rocks. ► BET surface area is a primary proxy for CH4 adsorption capacity in clay-rich rocks. ► Clay type affects gas-sorption capacity and the presence of moisture can greatly reduce gas-sorption capacity. ► Quantitative model prediction is developed to estimate the methane sorption capacity of organic-lean shales.