破碎煤层预抽钻孔快速成孔技术应用
Application of pre-drainage borehole rapid drilling technology in broken coal seam
摘要
碎软煤层施工瓦斯预抽钻孔常出现成孔率低、成孔深度浅、瓦斯抽采效果差等问题,孔壁应力不平衡是孔壁失稳的主要诱因.现有工艺仅优化钻杆结构虽能改善排渣,但塌孔造成的卡钻仍是制约成孔的关键.采用大扭矩钻机配套单螺旋大通孔钻杆,结合干式螺旋钻进与氮气辅助排渣成孔工艺,并使用不提钻下筛管完孔技术,筛管经钻杆内部送至孔底实现护孔.现场试验结果表明:钻孔平均深度达 107.2 m,最大孔深 150 m,成孔率由 40%提升至 65%,瓦斯抽采纯量提高1.5 倍,可满足工作面瓦斯预抽工程要求.
Problems such as low pore-forming rate,shallow pore-forming depth and poor gas drainage effect often occur in gas pre-drainage drilling in broken soft coal seam construction.Unbalanced stress on the hole wall is the main cause of instability of the hole wall.Although the existing technology only optimizes the structure of drill pipe,it can improve slag discharge,but the sticking caused by hole collapse is still the key to restrict hole formation.A high-torque drilling rig is used to match a single spiral large-bore drill pipe,combined with dry spiral drilling and nitrogen-assisted slag removal to form a hole,and the screen pipe is used to complete the hole without drilling,and the screen pipe is sent to the bottom of the hole through the drill pipe to protect the hole.The field test results show that the average drilling depth is 107.2 m,the maximum drilling depth is 150 m,the pore-forming rate is increased from 40%to 65%,and the gas drainage purity is increased by 1.5 times,which can meet the requirements of gas pre-drainage engineering in working face.
年，卷(期)：
2026, 45(10)
分类号：
TD713
机标分类号：
TD712
TD353
U445.551
在线出版日期：
2026年10月29日
基金项目：
2024GX-YBXM-486:陕西省重点研发计划项目，
