Despite the grooved drill pipe (GDP) has been applied in the soft coal seam in recent years, it remains unclear of the cinders transport mechanism in the annulus of GDP. In this study, the cinders transport model of GDP was developed based on an improved method, combining the kinetic theory of granular flow and Eulerian-Eulerian two-phase flow model. The annular fluid field characteristics and cinders transport laws of GDP were studied in this model by considering drag force, lift force, and virtual mass force. Finally, the precision of this model was verified via the experimental data. The results show that the annular velocity and cinders distribution present periodic variations with the drill pipe pitch. A role of guiding and tangential force on fluid field by the helix grooves is found. The volume fraction of residual cinders is dramatically reduced from 0.144 to 0.085 as the inlet velocity increases from 0.6 m/s to 1.2 m/s. This indicates the performance of cinders transport can be improved by increasing inlet velocity of drilling fluid.

尽管近年来在软煤层中采用了带沟槽的钻杆（GDP），但仍不清楚在GDP环空中煤渣的输送机制。在这项研究中，结合颗粒流动力学理论和欧拉-欧拉两相流模型，在改进方法的基础上建立了煤渣运输模型。在模型中考虑了阻力，升力和虚拟质量力，研究了国内生产总值的环状流场特征和煤渣输运规律。最后，通过实验数据验证了该模型的精度。结果表明，环形速度和煤渣分布随钻杆螺距呈周期性变化。发现螺旋槽在流体场上具有导向力和切向力。随着入口速度从0.6 m / s增加到1.2 m / s，残余煤渣的体积分数从0.144大大降低到0.085。这表明可以通过增加钻井液的入口速度来改善煤渣运输的性能。