The pore structure of coal significantly affects the adsorbability, desorption, and seepage behavior of coal-rock gas. This study firstly represents a comprehensive assessment of pore structure and fractal dimension characteristics for the low-medium rank coal of the Jurassic-Triassic, Kuqa Depression, Tarim Basin, China, with a focus on their implications for methane adsorption capacity. In addition, integration the laboratory and well log data (CMR_NG) are used to evaluate gas bearing property of coal seams. Coal samples of low-medium rank were analyzed using low-pressure CO2 adsorption (LP-CO2GA), low-temperature N2 adsorption (LT-N2GA), mercury intrusion porosimetry (MIP), nuclear magnetic resonance (NMR), and scanning electron microscopy (SEM). The adsorption-desorption isotherms of coal samples are predominantly Type H3 and H4, indicating parallel plate pores and ink-bottle or narrow slit pores, which promote coal-rock gas enrichment. Micropores, responsible for most specific surface area (SSA), dominate the pore structure, alongside macropores with two T2 peaks. Fractal dimensions (D1, D2 from LT-N2GA; D3, D4 from NMR) reflect pore characteristics, where higher D1 and D2 correlate positively with SSA and total pore volume (TPV) of micropores and mesopores. Langmuir volume (VL) correlates with D3, indicating greater adsorption capacity, while lower D4 suggests better connectivity and permeability. Furthermore, industrial components and gas bearing property are evaluated by using conventional well log and CMR_NG log. The favorable coal reservoir exhibits high fixed carbon content, a broad T1 spectrum, and bimodal T2 distributions from CMR_NG, indicating both adsorbed and free gas with high coal-rock gas content. These insights could enhance understanding of low-medium rank coal reservoir pore structure and fractal dimension characteristics, as well as their influence on methane adsorption, gas bearing property and seepage capacity.
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