高位大直径定向钻孔治理上隅角瓦斯技术实践

High-position and Large-Diameter Directional Drilling Technology Practice for Gas Treatment in Upper Corner

针对王庄煤矿综放工作面瓦斯涌出量大、上隅角瓦斯积聚的情况,提出采用高位大直径定向钻孔技术治理采空区和上隅角瓦斯超限问题。通过研究采空裂隙随工作面推进的演化过程,分析顶板裂隙发育高度,确定大直径高位定向长钻孔最佳布孔层位及钻孔结构,并进行工程实践。结果表明,在高瓦斯工作面通过布设大直径高位定向长钻孔,初始时钻孔瓦斯浓度相对较高,但随工作面的不断推进,钻孔抽采瓦斯浓度开始下降,且大直径高位定向长钻孔抽采上隅角瓦斯持续时间长,抽采瓦斯纯量稳定,钻孔抽采期间平均纯量为4.3 m3/min,钻孔平均抽采浓度为11.1%,有效解决了上隅角瓦斯超限问题,保障工作面的安全回采。

In view of the large gas emission and gas accumulation in the upper corner of the fully mechanized top coal caving face in Wangzhuang Coal Mine,a directional drilling technology with large di⁃ameter is proposed to control the gas overrun in the goaf and upper corner.By studying the evolution pro⁃cess of goaf fractures along with the advance of the working face,the development height of roof fractures is analyzed,and the optimal hole layout layer and drilling structure of large diameter high-level directional long boreholes are determined,and the engineering practice is carried out.The results show that the gas concentration in the boreholes is relatively high at the beginning through the arrangement of large-diameter high-level directional long boreholes in the high gas working face,but with the continuous progress of the working face,the gas concentration in the boreholes began to decline,and the large-diameter high-level directional long boreholes continued to extract gas from the upper corner for a long time,and the net amount of gas extracted was stable.The average net amount during the drilling drainage was 4.3 m3/min,and the average concentration of the boreholes was 11.1%,It effectively solved the problem of gas overrun at the upper corner and ensured the safe mining of the working face.