Effect of organic-matter type and thermal maturity on methane adsorption in shale-gas systems

► Organic matter is the key element to control gas adsorption in shales. ► TOC is a primary control on gas adsorption capacity. ► Organic-matter type and thermal maturity affect gas-sorption rate. ► The presence of moisture can greatly reduce gas-sorption capacity. ► Quantitative model prediction is developed for adsorbed gas estimate.