高瓦斯矿井长钻孔CO_2气相压裂增透试验研究

Experimental Study on Gas Fracturing Enhancement by Long Drilling of CO_2 in High Gas Mine

高瓦斯矿井煤层回采过程中地质条件复杂多变,常有瓦斯异常涌出现象,工作面经常发生瓦斯预警超限断电情况,严重制约工作面安全高效生产。为了提高顺层钻孔瓦斯抽采效果,降低瓦斯涌出不均衡性,采用CO_2气相压裂增透技术对煤层应力进行重新分布,使瓦斯应力分布均匀化,增大裂隙发育程度,提高瓦斯抽采率,从而有效降低瓦斯危害,杜绝瓦斯事故的产生。利用该技术后,单组钻孔的瓦斯抽采纯量是普通孔的4. 2倍,极大地提高了煤层瓦斯抽采量,加快了煤层瓦斯含量的降低,促进了矿井安全高效生产。

In the process of coal seam recovery in high gas nfines,the geological conditions are complex and changeable. There are oftenabnormal gas gushing phenomena. Gas warning and over linfit power outages often occur on the working surface, which seriously restricts the safe and efficient production of the working surface. In order to improve the effect of gas extraction and reduce the unbalanced gas enfission,the stress distribution of coal seams was redistributed by the CO2 gas fracturing technique,which made the gasstress distribution even,increased the crack development degree,and improved the gas extraction rate. In order to effectively reduce gashazards and prevent the occurrence of gas accidents. After using this technology, the gas extraction purity of single drilling group is 4.2times that of ordinary holes, which greatly improves the coal seam gas extraction amount, accelerates the reduction of coal seam gas content, and promotes the safe and efficient production of coal nfines.