Adsorbability of shale in coal measures and its influencing factors

In order to reveal the adsorption and gas-bearing characteristics of shale in coal measures, this study was based on the gas content, isotherm adsorption, high-pressure mercury injection, and liquid nitrogen adsorption of more than 200 coal shale in six major coal fields in Shanxi Province and Junggar basin. XRD diffraction and other measured data, the adsorption and gas characteristics of shale were analyzed, and the influencing factors were discussed. The results show that the measured gas content of shale is between 0-5.87 cm³/g, concentrated at 0.90-2.00 cm³/g; V_L is between 0.11-6.3 cm³/g with an average of 1.57 cm³/g. The adsorption capacity of shale gas was strong; p_L ranged from 0.16 to 8.65 MPa with an average of 3.28 MPa; the maximum adsorption capacity was positively correlated with porosity, organic matter abundance, organic matter maturity, and quality score of clay mineral. The relationship is negatively correlated with the quality score of illite-montmorillonite mixed layer and the average pore size.