为探究屯兰区块煤层气井压裂特征，以太原西山屯兰区块2号煤层为研究对象，通过对采煤工作面揭露的XST-167、XST-168、XST-176和XST-177 四口煤层气井进行地质编录、煤样宏观特征描述及CT分析，从多尺度研究煤层的压裂特征。结果表明：研究区煤层气井附近煤层主要分布斜交裂隙组成的“X”型压裂裂隙，在XST-177煤层气井附近有“T”型压裂裂隙。石英砂与压裂裂隙壁碰撞、摩擦产生煤粉，煤粉充填在裂隙内，对煤层气的产出有阻碍作用。通过对XST-168、XST-177 二口煤层气井揭露的井筒进行对比，发现XST-177煤层气井的压裂效果更好，更有利于煤层气的产出。煤层气井附近的煤大多为碎裂煤、碎粒煤，水力压裂破坏了煤体的原生结构，使煤体硬度降低，裂隙显著增加。部分煤样可以观测到石英砂镶嵌其上，主要集中在煤的层理面上，说明石英砂被压进煤层后，主要沿水平缝向煤层内延伸，与此处的最大主应力方向保持一致。通过CT扫描技术，对受压裂影响的煤样（压裂煤）和未受压裂影响的煤样（正常煤）进行扫描，发现压裂煤T1、T2中裂隙宽度大于100 μm的裂隙分别占总裂隙体积的58.8％和48.5％，裂隙数量上分别为23407条和19679条，而正常煤T3中裂隙宽度大于100 μm的裂隙仅占总裂隙体积的1.7％，裂隙数量仅为3504条，T1、T2较T3的裂隙宽度更宽，裂隙数量更多，说明压裂作用使煤样裂隙宽度和数量明显增加，压裂煤内部的孔裂隙更发育。

In order to explore the fracturing characteristics of coalbed methane wells in the Tunlan block, the No.2 coal seam in the Tunlan block, Xishan, Taiyuan was taken as the research object. The fracturing characteristics of the coal seams from multiple scales was studied through geological cataloguing, macroscopic characterization of coal samples and CT (Computed Tomography) analysis for four coal bed methane wells of XST-167, XST-168, XST-176 and XST-177, which were exposed at the coal mining face. The results shown that, the coal seam near the wells in the study area were mainly distributed with “X” type fractured fractures consisting of diagonally intersecting fractures, and there were “T” type fractured fractures near the XST-177 coalbed methane well. Collision and friction of quartz sand with fractured fracture walls produced pulverized coal, which filled in the fracture and hindered the output of coalbed methane. By comparing the drill holes exposed by the two coalbed methane wells of XST-168 and XST-177, it was found that the fracturing effect of the XST-177 coalbed methane well was better and more conductive to the output of coalbed methane. Most of the coals near coalbed methane wells were fragmented and crushed coal, and hydraulic fracturing destroyed the original structure of coal, which reduced the hardness of coal and significantly increased the cracks. Embedded quartz sand can be observed on some of the coal samples, which was mainly concentrated on the bedding surface, indicating that the quartz sand, after being pressed into the coal seam, mainly extended into the seam along the horizontal fracture, which was consistent with the direction of the maximum principal stress. By CT scanning technology, the coal samples affected by fracturing (fractured coal) and not affected by fracturing (normal coal) were scanned. It was found that, the fractures with a width greater than 100 μm in the fractured coals of T1 and T2 accounted for 58.8% and 48.5% of the total fracture volume, and the numbers of the fractures was 23407 and 19679, respectively. In normal coal T3, the fractures with width greater than 100 μm only accounted for 1.7% of the total fracture volume, and the number of fractures was only 3504. The width of the fractures in T1 and T2 was wider and the number of fractures was more than that in T3, which indicated that the width and number of fractures in the coal sample were significantly increased by the fracturing action, and the pores and fractures in the fractured coal were more developed.