In this study, the pore characteristics and the factors of maximum methane adsorption capacity (MAC) of mudstone in the early diagenetic stage (EDS) and the contribution rate of clay mineral (CM) adsorption were analyzed. In addition, the adsorption coupling effect of CM and organic matter (OM) was discussed. Studies have shown that pores of coal measure mudstone in the early diagenesis stage are mainly small pores with slanted platelike staggered and overlapped pores, with more pore opening directions. The main controlling factors of the maximum MAC of mudstone are OM and CM, and the direct expression is the pore surface area. In the EDS, the contribution rate of CM in mudstone is lower, while the contribution rate of OM to the MAC of mudstone is higher. There is an adsorption coupling effect of CM composition and OM. OM in mudstone is scattered, and the CMs have a supporting effect, which leads to OM in mudstone having a large contact area with the open space and has many effective pores. OM in coal is concentrated, and the surface area of OM per unit volume is small (compared with OM in mudstone). The compaction and deformation characteristics of CMs have a plugging/sealing effect on the pores of OM in the coal, which makes the effective pores of OM per unit volume in coal lower than those in mudstone.

本研究分析了早期成岩阶段（EDS）泥岩的孔隙特征、最大甲烷吸附量（MAC）及黏土矿物（CM）吸附贡献率的影响因素。此外，还讨论了CM与有机物（OM）的吸附耦合效应。研究表明，早期成岩阶段煤系泥岩的孔隙以小孔隙为主，呈斜板状交错重叠孔隙，孔隙开口方向较多。泥岩最大 MAC 的主要控制因素是 OM 和 CM，直接表达的是孔隙表面积。在EDS中，CM对泥岩的贡献率较低，而OM对泥岩MAC的贡献率较高。CM成分与OM存在吸附耦合作用。OM 在泥岩中分散，CMs具有支撑作用，导致与开放空间接触面积大、有效孔隙多的泥岩中的OM。煤中的有机质集中，单位体积有机质的表面积较小（与泥岩中的有机质相比）。CMs的压实变形特性对煤中OM的孔隙具有封堵作用，使得煤中单位体积OM的有效孔隙低于泥岩。