定向长钻孔整体水力压裂增透技术在赵固二矿的应用

针对赵固二矿煤层透气性低、钻孔有效影响半径小，实施定向长钻孔代替底板岩巷进行区域瓦斯治理期间钻孔工程量大、瓦斯抽采效果不理想的问题。结合煤层赋存特征及钻孔施工情况，采用定向长钻孔整体水力压裂增透技术，理论分析了合理坐封位置、压裂参数，完成200 m煤巷条带一次整体压裂，最大泵注压力24.3 MPa、累计注水量1 613 m³。并基于煤层全水分变化，考察确定了单个钻孔压裂影响范围达到巷道两帮30 m，有效改善了煤体储层特性，提高了煤层瓦斯抽采效率。在实现定向钻孔对预抽煤巷条带可靠控制的同时，最大程度降低了钻孔工程量、缩短了瓦斯治理周期，为实现矿区“以孔代巷”及高效安全开采提供了技术支撑。

Application of directional long borehole integral hydraulic fracturing and anti-permeability technology in Zhaogu No.2 Mine

In view of the low permeability of coal seams in Zhaogu No.2 Mine and the small effective radius of the drilling，the implementation of directional long boreholes instead of floor rock roads for regional gas control during the drilling process was large and the gas drainage effect was not ideal.It was combined with the occurrence of coal seams characteristics and drilling construction conditions，adopted directional long borehole integral hydraulic fracturing technology，theoretically analyzed reasonable setting positions and fracturing parameters，and completing an integral fracturing of a 200 m coal road with a maximum injection pressure of 24.3 MPa，the cumulative amount of water injection was 1 613 m3.Based on the change in the total moisture of the coal seam，it was investigated and determined that the impact range of a single borehole fracturing reached 30 m on both sides of the roadway，which effectively improved the characteristics of the coal reservoir and increased the efficiency of coal seam gas drainage.While realized the reliable control of pre-drainage coal lane strips by directional drilling，it minimized the amount of drilling engineering and shortens the gas treatment cycle，which provided strong technical support for the realization of "holes instead of roadways" and efficient and safe mining in the mining area.