高位定向长钻孔在综采工作面裂隙瓦斯抽采中应用

Application of High Position Directional Long Boreholes in Gas Extraction from Fractures in Fully Mechanized Mining Faces

针对综采工作面回采后采空区顶板裂隙中瓦斯集聚、容易导致回风隅角瓦斯超限问题,提出采用高位定向长钻孔对裂隙瓦斯进行抽采。依据30902综采工作面现场情况,通过理论计算以及瓦斯抽采经验,确定高位钻孔合理层位为9#煤层顶板20~26 m,水平方向上与回风巷间距为10~22 m;对高位定向长钻孔施工方案进行设计。现场应用后,高位定向长钻孔瓦斯抽采纯量、接抽时间较常规高位钻孔分别增加约3.72倍、4.15倍,通过裂隙瓦斯高效抽采可显著降低回风隅角瓦斯浓度,接抽期间回风隅角瓦斯浓度控制在0.56%以内,实现了裂隙瓦斯高效抽采,可为采面煤炭安全高效回采创造良好条件。

In response to the problem of gas accumulation in the roof cracks of the goaf after fully mechanized mining,which can easily lead to gas exceeding the limit in the return air corner,a high level directional long borehole is proposed to extract gas from the cracks.Based on the on-site situation of the 30902 fully mechanized mining face,through theoretical calculations and gas extraction experience,it is determined that the reasonable level of the high-level drilling hole is 20~26 meters from the roof of the 9#coal seam,and the horizontal distance from the return air roadway is 10~22 meters.Design the construction plan for high-level directional long drilling.After on-site application,the net amount of gas extraction and extraction time of high position directional long drilling increased by about 3.72 times and 4.15 times respectively compared to conventional high position drilling.Through efficient extraction of crack gas,the concentration of gas in the return air corner can be significantly reduced.During the extraction period,the concentration of gas in the return air corner is controlled within 0.56%,achieving efficient extraction of crack gas and creating good conditions for safe and efficient coal extraction in the mining face.