针对煤层钻孔水力排渣困难的问题，需要彻底了解水煤浆（动力水和钻屑混合物）的流变特性。通过钻屑水煤浆流变试验确定流变参数，建立了煤层钻孔水力排渣的水煤浆压降模型，数值分析了不同工况下钻孔水力排渣过程中压降的变化规律。研究结果表明，水煤浆的粒度范围、剪切速率和钻屑浓度对流变性能均有很大影响，剪切速率越大，剪切应力和剪切粘度也越大，钻孔沿线的压降受流速和钻屑浓度的影响较大。水煤浆较粗颗粒的存在也会导致管道沿线的压降较高。随着钻屑浓度的增加，剪切应力和剪切粘度的增加导致压降增大。基于水煤浆流变模型及压降计算模型，可对钻孔水力排渣的参数设计提供理论指导。

 In view of the difficulty of hydraulic slag discharge in coal seam drilling, it was necessary to thoroughly understand the rheological properties of coal water slurry ( mixture of dynamic water and drilling cuttings ). The rheological parameters were determined by rheological test of coal water slurry drilling cuttings. The pressure drop model of coal water slurry for hydraulic slag discharge in coal seam drilling was established, and the variation law of pressure drop in the process of hydraulic slag discharge in drilling under different working conditions was numerically analyzed. The results showed that the particle size range, shear rate and drilling cuttings concentration of coal water slurry had a great influence on the rheological properties. The greater the shear rate, the greater the shear stress and shear viscosity. The pressure drop along the drilling holes was greatly affected by the flow rate and drilling cuttings concentration. The presence of coarse particles of coal water slurry could also lead to higher pressure drop along the pipeline. With the increase of drilling cuttings concentration, the increase of shear stress and shear viscosity led to the increase of pressure drop. Based on the rheological model of coal water slurry and the pressure drop calculation model, it could provide theoretical guidance for the parameter design of drilling holes hydraulic slag discharge.