本煤层瓦斯抽采钻孔筛管完孔技术

Drilling Technology of Screen Pipe Gas Drainage Borehole Completion along Coal Seam

针对本煤层瓦斯抽采钻孔孔内存在的塌孔、阻塞等破坏钻孔完整性,影响瓦斯抽采效果问题,采用传统的裸孔下筛管办法又无法保障全孔段护壁的难题,从原因出发引出了筛管完孔技术,并介绍了其工艺特点及配套装备,结合现场实例分析了其应用效果。通过15 d的瓦斯监测显示,与裸眼钻孔对比,瓦斯平均浓度提高近75%,瓦斯纯流量提高近10倍,有效延长了钻孔使用周期,为施工相似条件地层提供了技术参考。

According to the problem of collapse, blocking damage drilling integrity existing hole drilling,effectting gas drainage, by the traditional way to put down screen pipes in the bare hole can not guaranteed the full screen hole collapse difficulties, leads to the technology of screen pipe completion form the reasons and introduces its technical characteristics and equipment combined, analyzes its application effect with the practical examples.Through the display of gas monitoring in 15 days, compared with the open hole completion, the average concentration of about 75% increase , the pure gas flows increased nearly 10 times, effectively prolongs the drilling cycle, provides technical reference for similar engineering conditions of formation.