煤储层水力压裂裂缝的有效支撑是确保煤层气高效产出的重要条件。通过可视化实验研究了裂缝形态、压裂液量、排量和性质对裂缝内支撑剂运移的影响。结果表明：首先，单一开度不变裂缝内支撑剂分布相对均匀，而局部单一变开度裂缝和网状裂缝内，支撑剂运移受压裂液流速变化、裂缝壁阻挡等作用，能够形成具有支撑剂柱和无支撑剂房的房柱式支撑；房柱式支撑对于深部应力敏感伤害严重的储层是一种有效的支撑方式。其次，单一变开度裂缝和网状裂缝内会发生明显的颗粒架桥效应，使得具有不同开度的各级裂缝允许通过的支撑剂粒径范围存在较大差异；同时当裂缝发生砂堵时，进一步注入压裂液会促进裂缝转向开启新裂缝，说明端部脱砂有利于缝网改造。最后，随压裂液量和排量增大，支撑剂运移距离增加，且网状裂缝内支撑剂能够进入更多分支裂缝，裂缝支撑面积显著提升；而向压裂液中加入减阻剂后黏度增加，能够有效提升压裂液携砂能力，并进一步增大裂缝内支撑剂运移距离和支撑面积。基于上述结果，建议采用大排量、大液量水力压裂，并采用低伤低阻压裂液与包含粉砂、细砂、中砂和粗砂的多级配支撑剂，提升储层内各类、各级裂缝支撑效果，促进流体高效产出。研究结果能够为煤层气、煤系气储层压裂工艺的优化提供实验支撑。

Effectively propping open hydraulic fractures in coal reservoirs plays an important role in ensuring the efficient production of coalbed methane (CBM). This study investigated the effects of fracture morphology and the volume, injection rate, and properties of fracturing fluids on proppant transport in fractures through visualized experiments. The results are as follows: (1) Proppants showed a relatively homogeneous distribution in simple fractures with a constant aperture. In contrast, they form room-and-pillar props composed of proppant pillars and proppant-free rooms in local simple fractures with varying apertures and reticular fractures due to the effects of the varying flow rates of fracturing fluids and the blocking of fracture walls on the proppant transport. These room-and-pillar props are effective for deep severely damaged stress-sensitive reservoirs; (2) Significant bridging effects of particles occurred in simple fractures with varying apertures and reticular fractures, resulting in great differences in the particle size ranges of proppants allowed to pass through fractures with different apertures. Meanwhile, further injecting fracturing fluids into fractures in the case of sand plug diverted fractures, forming new fractures. Therefore, tip screen-out (TSO) is favorable for the stimulation of fracture networks; (3) As the volume and injection rate of fracturing fluids increased, proppants migrated farther and those in reticular fractures entered more branch fractures, thus significantly increasing the propped fracture area. The viscosity of fracturing fluids increased after adding drag reducers to them. As a result, the sand-carrying capacity of fracturing fluids was improved effectively, and the transport distance and propped fracture area of proppants in fractures were further increased. Therefore, the authors of this study recommend using hydraulic fracturing with large injection rate and large-volume fracturing fluids and adopting low-damage, low-friction fracturing fluids and proppants with multiple grain sizes composed of silts and fine-, medium-, and coarse-grained sands. The purpose is to improve the propped effects for fractures of various types and different apertures in reservoirs and thus promote the efficient production of fluids. The results of this study can provide experimental support for the optimization of fracturing techniques for CBM reservoirs and coal-measure gas reservoirs.