基于高位定向长钻孔的采空区瓦斯抽采技术研究

Study on Goaf Gas Drainage Technology Using High Directional Long Borehole

为了研究高位定向长钻孔抽采采空区瓦斯效果,以吉宁煤矿2102工作面为研究对象,采用理论分析与数值模拟相结合的手段确定顶板高位定向长钻孔布置层位及钻孔结构,现场设计了五个高位定向长钻孔进行采空区瓦斯抽采。研究结果表明:煤层开采后,覆岩垮落带高度为20m,导水裂隙带高度为66m;裂隙区和压实区所呈嵌套关系的外侧梯形底角61°,内侧梯形底角50°,内外梯形之间宽度约为8.4m;高位钻孔应布置在煤层顶板以上40~60m,帮距15~48m,有效解决采空区上隅角瓦斯超限问题,瓦斯抽采效果良好,在保证安全生产的同时,实现了高效稳定治理采空区瓦斯的目的。

In order to study the effect of gas drainage in goaf by high-level directional long boreholes,taking 2102 working face of Jining Coal Mine as the research object,the layout and drilling structure of high-level directional long boreholes in roof are determined by means of theoretical analysis and numerical simulation.Five high-level directional long boreholes are designed for gas drainage in goaf.The results show that after coal mining,the height of overburden caving zone is 20 m and the height of water conducting fracture zone is 66 m;the lateral trapezoidal bottom angle 61° and the inner trapezoidal bottom angle 50° are nested in the fracture zone and compaction zone,and the width between the inner trapezoidal and the outer trapezoidal is about 8.4 m;the high-level boreholes should be arranged 40~60 m above the coal seam roof and 15~48 m above the top corner of the goaf,which can effectively solve the problem of gas exceeding the limit in the goaf.The gas drainage has good effect,while guaranteeing safety in production,the goal of controlling gas in goaf efficiently and stably is realized.