基于UDEC的顶板定向长钻孔瓦斯抽采技术研究

Research on gas extraction technology of directional long drilling in roof based on UDEC

为有效解决主焦煤业2301工作面采空区瓦斯涌出量大、易造成上隅角瓦斯超限等问题,设计使用顶板超长定向高位钻孔对采空区瓦斯进行抽采。高位钻孔的层位选择直接影响瓦斯抽采效果,基于UDEC数值模拟软件研究了采空区垂向“三带”分布,计算出顶板裂隙带高度为17~35 m,且在顶板上方8~17 m处为关键层,在顶板上方17~35 m区域内布孔有助于保护成孔不受破坏。顶板定向高位长钻孔抽采瓦斯能够有效提高抽采效率,瓦斯抽采效果明显,实现了“以孔代巷”的目的。通过考察顶板定向长钻孔瓦斯抽采纯量、瓦斯浓度以及与底板穿层钻孔抽采效果进行对比,并实测抽采后残存瓦斯含量变化情况,验证了顶板定向长钻孔瓦斯抽采了优势,保障了矿井安全生产。顶板定向高位长钻孔替代高抽巷技术具有较强的可行性及广阔的应用前景。

In order to effectively solve the problems of large gas emission in the goaf of the No.2301 working face of the Main Coking Coal Industry,which is prone to cause gas exceeding the limit in the upper corner,a design was used to extract gas from the goaf by using roof overlong directional high-level drilling.The selection of the layer of high-level drilling directly affects the gas extraction effect.Based on the UDEC numerical simulation software,the vertical distribution of"three zones"in the goaf was studied.It was calculated that the height range of roof fracture zone was 17~35 m,and the key layer was 8~17 m above the roof.Placing holes within an area of 17~35 m above the roof helped to protect the drilling from damage.Roof directional high-level long drilling gas extraction could effectively improve the extraction efficiency,and the gas extraction effect was obvious,realizing the goaf of"replacing roadway with hole",investigating the gas extraction purity and gas concentration of the directional high-level long drilling of the roof,and comparing it with the extraction effect of the drilling through the floor,and measuring the change of residual gas content after extraction,the advantages of gas extraction from the directional long drilling of the roof were verified.Roof directional high-level long drilling instead of high extraction roadway technology has strong feasibility and broad application prospects.