井地联合压裂是煤矿井下长钻孔分段压裂的发展趋势之一，压裂液经地面压裂泵加压后通过地面贯通井、煤矿井下长输管路进入煤矿井下长钻孔实施大排量压裂。支撑剂在长输管路中的悬浮运移规律对于优化设计加砂参数、避免管路中砂堵具有重要意义。通过室内实验评价压裂液的流变性能和携砂性能；基于欧拉−颗粒流理论构建数值模拟模型，研究水平管内支撑剂悬浮运移规律及其影响因素；探讨压裂液携带支撑剂运移的流态以及临界沉降流速的计算模型。结果表明：1%降阻剂的加入能够使活性水压裂液黏度提高3~5倍，支撑剂密度越小，压裂液黏度、砂比越高，支撑剂在压裂液中的沉降速度越小；支撑剂在水平管内的流动受到多因素的综合影响，压裂液流速越小，支撑剂密度和粒径越大，支撑剂在管道底部的沉积越严重，携砂效果越差；随着管路直径的增大，管道出口截面支撑剂体积分数最大的位置由管道中下部移动至管道底部，支撑剂流动对于管路的磨损加重；砂比越大，支撑剂间的相互作用越强，压裂液携砂能力降低；优选采用疏浚技术规范推荐的模型计算活性水携砂条件下的支撑剂临界沉降速度，随着管路直径的增大，所需的临界携砂排量呈指数式增大，提高压裂液黏度可降低携砂所需的临界排量。建立的携砂运移临界排量模型和总结的支撑剂运移规律可对管路直径和压裂液排量进行优化匹配，为井地联合压裂施工提供理论支撑。

Integrated well and ground fracturing is a developmental trend for the staged fracturing of underground long boreholes in coal mines. Using the integrated fracturing technology, the fracturing fluids, after being pressurized using a ground fracturing pump, enter long boreholes in underground coal mines through ground penetrating wells and long distance pipelines, aiming to achieve fracturing with high injection rates of fracturing fluids. The suspension and transport patterns of proppants in long distance pipelines hold critical significance for optimizing parameters related to proppant adding and avoiding sand plugging in pipelines. This study evaluated the rheological properties and proppant carrying capacity of fracturing fluids through laboratory experiments. Based on the Euler-Euler-based granular flow theory, this study constructed a numerical simulation model to investigate the suspension and transport patterns of proppants in horizontal pipelines and their influencing factors. Moreover, this study explored the flow regimes in which fracturing fluids carry proppants and the calculation model of critical settling velocities. The results are as follows: (1) Adding 1% of friction reducer can increase the viscosity of active water-based fracturing fluids by 3‒5 times. A lower proppant density, a higher fracturing fluid viscosity, and a higher proppant concentration result in a lower proppant settling velocity in fracturing fluids. (2) The flow of proppants in horizontal pipelines is subjected to multiple factors. A lower flow rate of fracturing fluids, as well as a higher density and larger particle size of proppants, can lead to more severe proppant settling at the pipeline bottom and a low proppant carrying capacity. (3) With an increase in the pipeline diameter, the position where the proppant volume fraction at the pipeline outlet cross-section peaks would shift from the middle to lower part of the pipeline to the bottom of the pipeline, accompanied by aggravated pipeline wear caused by proppant flow. (4) A larger proppant concentration corresponds to stronger interactions between proppants, which can reduce the proppant carrying capacity of fracturing fluids. (5) The model recommended by the Technical Code of Dredging Engineering was employed to calculate the critical settling velocity of proppants when active water-based fracturing fluids were adopted. The calculation results show that the critical injection rate of fracturing liquids required for proppant carrying increases exponentially with the pipeline diameter and that the critical injection rate can be reduced by increasing the fracturing fluid viscosity. The model of the critical injection rate of fracturing fluids built in this study and the proppant transport patterns obtained in this study can assist in the optimization of and the matching between pipeline diameter and the injection rate of fracturing fluids, thus providing theoretical support for integrated well and ground fracturing.