定向钻进技术在煤矿保护层开采卸压瓦斯抽采中的应用

针对西北某煤矿上保护层开采过程中卸压瓦斯大量逸散至工作面,常规钻孔存在工程量大、抽采效果差等问题,采用煤矿井下定向钻进技术对下部被保护煤层卸压逸散出的游离瓦斯进行提前抽采,并将其抽采效果与常规钻孔进行对比分析,同时对不同层位的定向钻孔瓦斯抽采效果进行考察对比.研究表明,同一区域的定向钻孔瓦斯抽采效果优于常规钻孔,其单日...

Application of directional drilling technology in pressure relief gas extraction of protective seam mining in coal mine

In view of the large amount of pressure relief gas escaping to the working face in the process of mining the upper protective layer of a coal mine in Northwest China，there are many problems in conventional drilling，such as large engineering amount and poor drainage effect.The directional drilling technology is used to extract the free gas released from the lower protected coal seam in advance，and the drainage effect is compared with the conventional drilling，and the directional drilling at different layers is also analyzed.The effect of hole gas drainage is investigated and compared.The results of engineering practice show that the gas drainage effect of directional drilling is better than that of conventional drilling in the same area，and the gas drainage amount of 100 meters per day is 25.2 times of that of conventional drilling.Through the analysis and comparison of gas drainage data of directional drilling in different layers，the results show that the comprehensive gas drainage effect of No.3 directional borehole close to the roof of the protected coal seam is the best，the average gas drainage concentration is 77.3%，and the pure drainage volume is 5.3 m³/min，which is far better than the conventional drilling and other directional drilling.The research results provide technical ideas for gas prevention and control in similar mines.