煤层瓦斯抽放钻孔的二次封孔方法研究

针对煤层钻孔抽放瓦斯后煤层孔隙裂隙发育致使瓦斯浓度下降,钻孔有效抽放期缩短的技术难题,首次提出二次封孔方法.阐述了二次封孔方法的基本原理,建立了微细膨胀粉料颗粒在孔隙裂隙中运动的数学模型,并在晋城煤业集团公司寺河矿开展了6个月的现场工业性试验.结果表明:应用二次封孔方法可提高瓦斯抽放浓度25%～50%,延长钻孔的有效瓦斯抽放期3个月.

A Study of the Second Hole Sealing Method to Improve Gas Drainage in Coal Seams

Gas concentrations drop, and the effective gas drainage period of holes is shortened, because pores and cracks in the coal seam become completely developed after gas drainage. The'second hole' sealing method is proposed as a solution to this problem. The principles are described and a mathematical model is formulated to describe the movement of fine expansion particles within the pores and cracks of the coal seam. An industrial scale test of this method was carried out over a period of six months at the Sihe mine of the Jincheng Mine Industry Group. The gas drainage concentration was improved by 25 to 50% after application of the method and the period of effective gas drainage was extended for three months.