煤储层孔隙结构与甲烷吸附能量变化的非均质性特征

煤储层具有复杂的孔隙结构，在吸附甲烷气体过程中伴随能量变化。为研究煤储层孔隙和甲烷吸附过程中能量变化的非均质特性，使用分形维数分析煤孔隙的非均质性，运用吸附势和表面自由能理论分析等温吸附过程中的能量变化非均质性。结果表明：PY-1、PB-1、PB-2样品主要发育微孔，PY-2样品主要发育大孔，不同样品的孔隙分布差异明显；微孔是吸附甲烷的主要场所，但并非是影响甲烷吸附量的决定因素。煤的孔隙结构和本身性质影响了煤吸附甲烷的非均质性选择，镜质组含量越高，孔隙结构越复杂，孔隙分形维数越大，非均质性越强；甲烷吸附量越高，吸附势和表面自由能变化越大。

The heterogeneity characteristics of pore structure and methane adsorption energy change in coal reservoir

Coal reservoirs have a complex pore structure, which is accompanied by energy changes during the adsorption of methane gas. To study the heterogeneity of energy changes during the pore and methane adsorption processes in coal reservoirs, fractal dimension analysis is employed to analyze the heterogeneity of coal pores. The heterogeneity of energy changes during the isothermal adsorption process is analyzed using adsorption potential and surface free energy theory. The results show that sample PY-1, PB-1, and PB-2 mainly develop micropores, while sample PY-2 mainly develops macropores, and the pore distribution of different samples is significantly different. Micropores are the main sites for methane adsorption, but not the determining factor affecting methane adsorption. Coal''s pore structure and inherent properties exert a significant influence on the heterogeneity of methane adsorption. As the vitrinite content increases, the complexity of pore structure and the fractal dimension of pores also increase, leading to enhanced heterogeneity. Consequently, methane adsorption exhibits higher uptake, accompanied by more pronounced variations in adsorption potential and surface free energy.