煤层超高压水力割缝增渗工艺参数优化研究

Study on optimization of process parameters of ultra-high pressure hydraulic slotting for permeability enhancement in coal seam

针对国内某煤矿煤层瓦斯抽采流动阻力大、抽采困难的问题,采用试验的方法在3001煤层A32工作面进行超高压水力割缝增渗工艺参数的优化研究,通过控制变量法研究工艺参数变化对瓦斯抽采效果的影响。结果表明,割缝时间为40 min、割缝间距为3 m、割缝压力为50 MPa、钻杆割缝旋转速度为70 r/min时,增渗效果最好。同时,通过在同一煤层进行钻孔技术对比发现,使用优化后的高压水力割缝工艺参数进行增渗,在割缝钻孔数量相同的条件下,瓦斯平均抽采纯量是传统钻孔的2倍,钻孔平均出煤量提高约45%,效果显著。

Aiming at the problems of large flow resistance and difficulty of gas extraction in coal seam of a coal mine in China,an experimental method was used to optimize the process parameters of ultra-high pressure hydraulic slotting and permeability enhancement in the A32 working face of No.3001 coal seam,and the influence of process parameters on gas extraction effect was studied by the control variable method.The results show that the permeability enhancement effect is best when the slotting time is 40 min,the slotting spacing is 3 m,the slotting pressure is 50 MPa,and the drill pipe slotting rotation speed is 70 r/min.Meanwhile,through the comparison of drilling technology in the same coal seam,the optimized high pressure hydraulic slotting process parameters are used to enhance the permeability,under the condition of the same number of slotting and drilling,the average gas extraction is twice that of traditional drilling,and the average coal output is increased by about 45%,with remarkable effect.