孟家窑煤业水力割缝卸压参数试验研究

Experimental Study on Pressure Relief Parameters of Hydraulic Slot Cutting Technology in Mengjiayao Coal Mine

针对煤矿开采过程中面临的瓦斯灾害的威胁,分析了煤体渗透性的影响因素及高压水射流割缝卸压技术的增透机理。在孟家窑煤业5#煤层进行了水力割缝增透强化瓦斯抽采的试验研究,针对切割压力、切割时间、孔内切割间距等割缝参数进行了试验研究。水力割缝后单孔瓦斯排气量从300 L提升到350 L,抽采前10 d的孔内平均瓦斯浓度由22.27%增加到26.66%。对比试验数据显示切割最优压力为70 MPa,切割最优时间为3 min,切割最优间距为1.0 m。最后从数学角度分析并得出水力割缝技术可以有效地释放煤层中的体积应力,提高煤层的透气性,从而提高钻孔内瓦斯浓度百分比,延长抽采时间,提高抽采总量。

In view of the threat of gas disaster during the mining,analyses the influence factors of coal permeability and the mechanism of hydraulic slot cutting as a pressure relief technology.Strengthening gas extraction experiment research of hydraulic slot cutting technology were studied in west 5#coal seam in Megjiayao coal mine.In view of the cutting parameters of pressure,cutting time,cutting spacing and hole spacing.After hydraulic cutting,the gas drainage volume of a single hole increased from 300 L to 350 L,and the average gas concentration in the hole increased from 22.27%to 26.66%in the 10 days before extraction.According to the experiment data,the optimal cutting pressure is 70 MPa;the optimal cutting time is 3 minutes;the optimal cutting spacing is 1.0 meter.Finally from the perspective of mathematical analysis and hydraulic cutting seam technology can effectively release the volume stress in coal seam,improve coal seam permeability,thus improve the gas density in the borehole drilled in the percentage of extraction time,increase extraction volume.