Pores and fractures and their connectivity play a significant role in coalbed methane production. To investigate the growth characteristics and connectivity of pores and fractures in coal parallel and perpendicular to the bedding plane, the pores and fractures of high-rank coal samples collected from the southern Qinshui Basin were measured by low-field nuclear magnetic resonance, X-ray-computed tomography and field emission scanning electron microscopy. Then, the determinants of their connectivity were further discussed. The results show that the high-rank coal samples have similar pore size distributions both parallel and perpendicular to the bedding plane. They primarily contain mesopores (2–50 nm in width), followed by macrospores (> 50 nm in width). The research indicated that the high-rank coal connectivity parallel to the bedding plane is significantly better than that perpendicular to the bedding plane. The connectivity of high-rank coal is mainly determined by throats, and the orientation of the pores and fractures. The two connectivity modes in high-rank coal are “pore connectivity,” in which the throats are mainly pores with a low coordination number, and “microfissure connectivity”, in which the throats are mainly microfissures with a high coordination number.

中文翻译：

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通过NMR和X射线CT平行于垂直于顺层平面的高级煤结构的特征。

孔隙和裂缝及其连通性在煤层气生产中起重要作用。为了研究平行于和垂直于层理面的煤的孔隙和裂缝的生长特征和连通性，利用低场核磁共振，X射线测量了沁水盆地南部高品位煤样品的孔隙和裂缝。电脑断层扫描和场发射扫描电子显微镜。然后，进一步讨论了它们的连通性的决定因素。结果表明，高品位煤样品在平行和垂直于顺层平面上具有相似的孔径分布。它们主要包含中孔（宽度2–50 nm），其次是大孢子（宽度> 50 nm）。研究表明，平行于顺层平面的高阶煤连通性明显好于垂直于顺层平面的煤阶连通性。优质煤的连通性主要取决于喉道，孔隙和裂缝的方向。高阶煤的两种连通性模式是“孔连通性”和“微裂隙连通性”，其中“喉孔”主要是配位数低的孔；“微裂隙连通性”，其中喉部主要是具有高配位数的微裂缝。