Pores and fractures are important components of flow channels in coal-measure gas reservoirs. While considerable studies have been conducted on pore structure evolution, very few studies have investigated the fracture distribution and self-similarity characteristics. To reveal the characteristics of fracture distribution in coal and shale reservoirs, computed tomography studies were performed on 15 coal and shale samples from the Shanxi and Taiyuan formations. The results show that the fracture distribution of samples of the same lithology differs significantly, and the fracture distribution heterogeneity of shale samples is much higher than that of coal samples. In shale, the heterogeneity of fracture distribution is mainly caused by pores and fractures smaller than 2 µm in the z-direction, with relatively little contributions from pores and fractures in the x and y directions. However, the heterogeneity of fracture distribution in coal is mainly controlled by pores and fractures larger than 2 µm in all directions, and the difference between the three directions is minor. It was shown that a great number of microscopic pores and fractures contribute to the highest fractions of porosity in different lithological samples. This method is useful for determining the fracture distribution characteristics in shale and coal-measure gas reservoir.

孔隙和裂缝是煤系气藏流道的重要组成部分。虽然对孔隙​​结构演化进行了大量研究，但很少有研究探讨裂缝分布和自相似特征。为揭示煤和页岩储层裂缝分布特征，对来自山西和太原地层的 15 个煤和页岩样品进行了计算机断层扫描研究。结果表明，同一岩性样品裂缝分布差异显着，页岩样品裂缝分布非均质性远高于煤样。页岩中裂缝分布的非均质性主要是由z方向小于 2 µm 的孔隙和裂缝引起的- 方向， x和 y 方向的孔隙和裂缝贡献相对较小。但煤岩裂缝分布的非均质性主要受控于各个方向大于2 µm的孔隙和裂缝，三个方向的差异较小。结果表明，在不同岩性样品中，大量微观孔隙和裂缝对孔隙率的最高分数有贡献。该方法可用于确定页岩和煤系气藏裂缝分布特征。