煤层预抽钻孔合理封孔深度研究

Study on Reasonable Sealing Depth of Coal Seam Pre-drilling Holes

为确定高河矿3#煤层预抽钻孔的合理封孔深度,提高煤层预抽钻孔瓦斯抽采效率,利用钻屑量指标S与地应力间的关系确定煤层“三带”范围。通过数据分析确定高河矿合理封孔深度为16m,并在现场布置封孔深度分别为11m、16m、18m、22m的钻孔进行抽采效果的考察。结果表明,11m封孔深度的钻孔瓦斯抽采体积分数明显小于16m、18m、22m封孔深度,16m封孔深度最为合理。该方法可为其他矿井确定合理封孔深度提供参考,以保证瓦斯高效抽采。

In order to determine the reasonable sealing depth of pre-drilling holes in 3#coal seam of Gaohe Coal Mine and improve the gas drainage efficiency of coal seam pre-drainage,this paper determined the"three belts"range of the coal seam by using the relationship between the S index of drilling cuttings amount and the ground stress.Through data analysis,it was determined that the reasonable sealing depth of Gaohe Coal Mine was 16 m.The drilling results with the sealing depths of 11 m,16 m,18 m and 22 m were arranged on site to investigate the drainage effect.The results showed that the drilling gas volume fractian of 11 m sealing depth was obviously lower than that of 16 m,18 m and 22 m sealing depth,and the 16 m sealing depth was the most reasonable.The method can provide reference for determining the reasonable sealing depth of other mines,and ensure efficient gas extraction.