瓦斯抽采钻孔动态密封技术

Dynamic sealing technology of borehole gas drainage

为了增强瓦斯抽采钻孔密封效果,提高瓦斯抽采效率,提出了瓦斯抽采钻孔动态密封技术。通过"两堵"主动支撑密闭和注入不凝固黏稠膏体材料进行密封,可有效封堵钻孔及周围煤体裂隙,并在钻孔受扰动影响而密封失效后,采取二次或多次注浆以提高钻孔瓦斯抽采浓度,延长瓦斯抽采钻孔使用期限,提高瓦斯抽采效率。经现场验证,动态密封技术密封效果优于常规水泥注浆封孔,且在二次注浆后抽采浓度明显上升,有效解决了传统瓦斯抽采钻孔密封效果差、固态封孔易漏气、密封失效难以补救等技术难题。该技术具有一定的推广意义。

To improve the sealing effect and efficiency of borehole gas drainage,a dynamic sealing technology was proposed. Using ‘two-site blockage’as sealing support and injecting non-condensable,pasty material can effectively seal the fracture around the borehole in the coal seam.And even there exists the sealing failure of the borehole due to the disturbance,adopting the second or multiple grouting technology can improve the borehole gas concentration and drainage efficiency and extend the service life of the borehole.The experiments show that the sealing effect of dynamic sealing technology for borehole gas drainage is much better than traditional sealing cement grouting technology,and the gas drainage concentration is significantly increased after the second grouting.The technical problems such as poor sealing effects,easy leakage of solid sealing,and irreparable after sealing failure appeared in traditional borehole gas drainage can be effectively solved with this technology,which makes it meaningful for future generalization.