关键词: 高位定向长钻孔, 数值模拟, 上隅角, 采空区

Abstract: 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. Smith drainage has good effect, and saves a lot of control costs, so as to achieve the goal of efficient and stable control of gas in goaf.