土城矿顺层抽采钻孔合理封孔深度研究

Research on Reasonable Sealing Depth of Bedding Drilling Borehole in Tucheng Coal Mine

瓦斯抽采钻孔封孔深度对煤层瓦斯抽采效果起着至关重要的作用。针对目前矿井普遍利用经验法确定顺层瓦斯抽采钻孔封孔深度存在的不足,采用数值模拟、钻屑法及封孔质量仪对巷道围岩应力增高带长度进行研究,进而综合确定顺层钻孔的合理封孔深度,并在土城矿21126工作面试验区域进行现场应用。研究结果表明:利用该方法确定土城矿21126工作面合理封孔深度应为20 m,新实施钻孔组抽采3个月其平均瓦斯抽采浓度为矿井原抽采钻孔组的2.21倍,显著提高了顺层钻孔的抽采效率。

The reasonable sealing depth of gas drainage drilling borehole plays a vital role in the coal seam gas drainage.For the shortcomings that the current mine generally use experience to determine the hole depth of the bedding gas extraction hole,the numerical simulation,the cuttings and the sealing mass spectrometer were used to study the length of the stress zone in the roadway.Furthermore,the reasonable sealing depth of bedding drilling was determined,and it was applied in Tucheng coal mine21126 working face.The results showed that the reasonable sealing depth of the 21126 working face in Tucheng coal mine was 20 m,and the average gas extraction time in 3 months of the newly implemented drilling group was 2.21 times of that of the original mine drainage drilling group.It significantly improved the extraction efficiency of bedding drilling.