Effect of the Clay Mineral Content on Methane Adsorption in Marine–Continental Transitional Shales

作者：Jingqiang Tan, Bohao Wang, Xinyao Ma, Huricha Wu, Haonan Han, Ruining Hu · 发表于：Energy & Fuels · 年份：2025 · DOI：10.1021/acs.energyfuels.5c01753 · 被引用次数：5 · 研究领域：Hydrocarbon exploration and reservoir analysis、Methane Hydrates and Related Phenomena、Atmospheric and Environmental Gas Dynamics

Clarifying the effect of clay minerals on shale methane adsorption is crucial for shale gas exploration and development. Most of the previous studies focused on the effect of organic matter on methane adsorption, but the mechanism of the effect of the clay mineral content on shale methane adsorption remains unclear. Here, we conducted high-pressure methane adsorption experiments on two groups of organic-rich shale samples in the Longtan Formation. The content of organic matter is similar among the samples, but the clay mineral content varied significantly. The results show that, under the same temperature and pressure conditions, shales with a high clay mineral content (greater than 40%) have higher methane adsorption capacity compared to shales with a low clay mineral content (less than 32%). A series of thermodynamic parameters, such as enthalpy change (Δ H ), adsorption heat ( Q st ), Gibbs free energy (Δ G ), and entropy change (Δ S ), indicated that shale with a high clay mineral content adsorbs more methane molecules. At the same time, aggregates of organic matter and clay minerals were widely distributed in clay-mineral-rich shales. Different from isolated organic matter or clay minerals, aggregates of organic matter and clay minerals can significantly affect the methane adsorption capacity. On the one hand, the aggregates could improve the pore system and increase the specific surface area, providing more adsorption sites for methane molecules. On the other hand, func...