碾焉煤业高位大直径定向钻孔应用研究

碾焉煤业综采工作面采用"U"型通风,回采过程中上隅角风流不畅,为解决上隅角瓦斯浓度超限现象频发的问题,设计在4202工作面采用高位大直径定向长钻孔抽采采空区瓦斯,通过理论分析计算初步确定定向钻孔的布置层位,数值模拟研究确定最佳的抽采负压为15 kPa,定向钻孔距离煤层底板的最佳距离20 m,在4202工作面回风绕道布置钻场进行高位大直径定向钻孔的应用,应用期间钻孔抽采瓦斯平均浓度为18%,上隅角瓦斯稳定在0.4%左右,对于上隅角瓦斯治理及抽采效果良好。

Application research of high position and large diameter directional drilling in Nianyan Coal Industry

U-shaped ventilation was adopted in the fully mechanized coal mining face of the Nianyan Coal Industry.The wind flow at the upper corner was not smooth during the mining process.The diameter of directional long boreholes was used to extract gas in the goaf,and the theoretical layout of the directional boreholes was initially determined through theoretical analysis.Numerical simulation studies showed that the optimal drainage negative pressure was 15 kPa,and the optimal distance between the directional boreholes and the bottom of the coal seam was at a distance of 20 m,the drilling field was arranged in the return air bypass of the 4202 working face for high-level large-diameter directional drilling.During the application,the average concentration of gas extracted during drilling was 18%,and the gas at the upper corner was stable at about 0.4%,with good effect of corner gas treatment and drainage effect.