The Junggar Basin contains widely distributed Jurassic low-rank coal seams (Badaowan Fm. J\(_1\)b, Xishanyao Fm. J\(_2\)x) with abundant coalbed methane (CBM) resources. Integrating proximate analysis, maceral identification, vitrinite reflectance, low-temperature N\(_2\) adsorption, high-pressure mercury intrusion, and NMR, this study characterizes the petrological properties, pore-space characteristics, and gas storage mechanisms of J\(_1\)b and J\(_2\)x low-rank coals in the Baijiahai-Dinan area. Results show: J\(_1\)b is bright coal (vitrinite: 74.1%-88.3%, R\(_o\): 0.67%), while J\(_2\)x ranges from semibright to dull coal (vitrinite: 57.2%, R\(_o\): 0.71%), corresponding to long-flame... More >