Understanding the methane adsorption mechanism in shale, especially for shale with abundant microfossils, is significant for guiding the exploration and development of shale gas. In this study, two groups of organic-rich shale samples derived from the Wufeng-Lungmachi formations were selected for methane adsorption experiments: one core sample contains abundant radiolarian fossils, while the other core sample does not contain any radiolarian fossils. Through a series of calculations and comparisons of thermodynamic studies between radiolarian-rich shale and non-radiolarian shale, the results show that the absolute adsorption of methane in radiolarian-rich shale is greater than the absolute adsorption of methane in non-radiolarian shale at the same pressure and temperature. In addition, the difference in the thermodynamic parameters such as the isosteric heat of adsorption (Q_st), enthalpy change (ΔH), standard entropy change (ΔS⁰) and Gibbs free energy change (ΔG) between radiolarian-rich shale and non-radiolarian shale indicates that the interaction between radiolarian-rich shale and methane molecules is strong, and that radiolarian-rich shale is likely to have more adsorbed methane than non-radiolarian shale under similar geological conditions. Two plausible explanations are proposed to explain the methane adsorption mechanisms in radiolarian-rich shale. On the one hand, the biological pores developed in radiolarian fossils provide some adsorption sites for methane molecules. On the other hand, the amorphous silica in the radiolarian fossils can combine with organic molecules to form a new functional group called trimethylsilane, which possesses a hydrophobic character. The organic-inorganic pore surface provides a new perspective for interpreting methane adsorption mechanisms in shale.

了解页岩中的甲烷吸附机理，特别是对于微化石含量丰富的页岩，对指导页岩气的勘探和开发具有重要意义。在这项研究中，选择了五峰-龙町组的两组富含有机质的页岩样品进行甲烷吸附实验：一个岩心样品包含丰富的放射虫化石，而另一岩心样品中则不含任何放射虫化石。通过一系列计算和比较富放射性页岩和非放射性页岩的热力学研究，结果表明，富放射性页岩中甲烷的绝对吸附大于非放射性页岩中甲烷的绝对吸附。相同的压力和温度。此外，Q _st），焓变（ΔH），标准熵变（ΔS ⁰）和吉布斯自由能变化（ΔG）在富含放射性的页岩和非放射性的页岩之间，表明富含放射性的页岩与甲烷分子之间的相互作用很强，并且在类似的地质条件下，富含放射性的页岩比非放射性的页岩吸附甲烷的可能性更高。提出了两个合理的解释来解释富含放射虫的页岩中甲烷的吸附机理。一方面，放射虫化石中发育的生物孔为甲烷分子提供了一些吸附位点。另一方面，放射虫化石中的无定形二氧化硅可以与有机分子结合形成一个新的官能团，称为三甲基硅烷，该基团具有疏水性。有机-无机孔隙表面为解释页岩中甲烷的吸附机理提供了新的视角。