四翼内凹刻槽钻杆高效排渣钻进技术研究

Research on efficient slag discharge drilling technology of four-wing concave groove drill rod

为解决松软煤层钻进钻孔排渣通道堵塞这一制约钻孔施工效果的关键难题,基于优化钻杆截面形状以增大排渣空间、预防钻孔堵塞这一理念,提出四翼内凹刻槽钻杆几何设计构想,通过孔内排渣阻力力学方程计算验证、钻杆排渣效果数值模拟,分析钻杆结构参数对排渣性能的影响,研制四翼内凹刻槽钻杆并在某矿进行工业性试验。研究结果表明:相较于传统圆状刻槽钻杆,四翼内凹刻槽钻杆在施工过程中具有更大的排渣空间,通过孔内沿程阻力计算对比,四翼内凹刻槽钻杆孔内沿程阻力较圆状刻槽钻杆低13%;数值模拟计算结果表明,当弧形内凹切槽对钻杆的圆心角α=35°、切入深度|EF|=4 mm时,渣体运移距离最大,平均运移速度最大,排渣性能最优;工业性试验表明,使用四翼内凹刻槽钻杆施工钻孔,班进尺长度和终孔深度得到显著提升。研究结果可为煤矿瓦斯抽采钻孔钻具设计提供参考。

In order to solve the key problem of blockage in the borehole slag discharge channel during the drilling in soft coal seams,based on the concept of optimizing the cross-sectional shape of drill rod to increase slag discharge space and prevent borehole blockage,a geometric design conception of the four-wing concave groove drill rod was proposed.Through the calculation of the mechanical equation of slag discharge resistance in the borehole and the numerical simulation of the slag discharge effect of drill rod,the influence of the structural parameters of drill rod on the slag discharge performance was analyzed.The four-wing concave groove drill rod was developed,and the industrial tests were conducted in a mine.The results show that compared to the traditional circular groove drilling rod,the four-wing concave groove drill rod has a larger slag discharge space during the construction process.Through the calculation and comparison of the on-way frictional resistance in the borehole,the on-way frictional resistance of the four-wing concave groove drill rod is 13%lower than that of the circular groove drill rod.The numerical simulation results show that when the central angle of the arc-shaped concave groove on the drill rod is 35 degrees and the cutting depth is 4 mm,the slag transportation distance and the average transportation speed are the greatest,and the slag discharge performance is the optimal.The industrial tests show that the use of four-wing concave groove drill rod for drilling significantly improves the length of per-shift drilling depth and the depth of final hole.The research results can provide reference for the design of drilling tools for gas drainage in coal mines.