A combination of physical and numerical simulations is employed to compare the differences in desorption deformation and desorption volumes of coal samples under varying depressurization paths, aiming to understand their impact on coalbed methane (CBM) extraction. In this work, two medium-rank coal samples from the central-eastern region of the Qinshui Basin were chosen for the desorption–strain experiments. The experiment facilitated real-time observation of desorption gas volumes and coal matrix deformation under various depressurization paths. Finite element analysis was utilized to model and analyze the evolution of pore pressure during depressurization and desorption. The research outcomes indicate a dependency of desorption gas volumes on the chosen depressurization path. With the slow depressurization path, the desorption gas volume over 12 h was 8% higher than that achieved with the rapid depressurization path. When the pressure difference across the pores fell below the pressure difference required for gas migration, the gas cannot overcome the resistance, leading to residual gas being trapped in the pores. With the slow depressurization path, the coal matrix exhibited notably lower residual pore pressure and remaining gas volume compared to the rapid depressurization path. The differences in desorption volumes under various depressurization paths were mainly driven by the pore structure and matrix strain. Rapid depressurization led to pore contraction, which decreased pore size and connectivity, increasing resistance to gas migration and decreasing absorption rates. Conversely, the slow depressurization path led to a more gradual pore contraction and minimal strain, supporting the continuous production of CBM.

采用物理和数值模拟相结合的方式，比较不同降压路径下煤样解吸变形和解吸体积的差异，旨在了解其对煤层气抽采的影响。本工作选取沁水盆地中东部地区的两个中阶煤样进行解吸应变实验。该实验有助于实时观察各种降压路径下的解吸气体量和煤基质变形。利用有限元分析对降压和解吸过程中孔隙压力的演变进行建模和分析。研究结果表明解吸气体体积对所选减压路径的依赖性。采用慢速降压路径，12 h 内的解吸气体量比快速降压路径高出 8%。当孔隙间的压差低于气体运移所需的压差时，气体无法克服阻力，导致残余气体被困在孔隙中。与快速降压路径相比，慢速降压路径下煤基质的残余孔隙压力和剩余瓦斯体积显着降低。不同降压路径下解吸体积的差异主要由孔隙结构和基质应变驱动。快速减压导致孔隙收缩，从而减小孔隙尺寸和连通性，增加气体运移阻力并降低吸收率。相反，缓慢的降压路径导致孔隙更加逐渐收缩和最小应变，支持煤层气的连续生产。