集束型枝状定向钻孔群一孔两消瓦斯抽采技术与应用

Technology of Gas Extraction for Two Places Outburst Elimination with One Hole by Cluster-type Multi-branch Directional Hole Group and Application

针对矿井工作面开采和巷道掘进对瓦斯抽采治理的需要,提出集束型枝状定向钻孔群一孔两消瓦斯治理技术,介绍了其定义和基本原理、钻孔布置与施工工艺流程。结合保德煤矿煤层厚度大、煤质坚硬,夹矸层多、透气性差、瓦斯压力大等特点,开发了钻孔轨迹随钻测量技术、钻孔轨迹随钻人工控制技术和多分支枝状钻孔施工技术,并研制选配了由定向钻机、随钻测量系统、螺杆马达、定向钻杆和定向钻头等组成的定向钻进装备,形成完善的技术与装备体系。在保德煤矿81309工作面进行了技术应用,共施工集束型枝状定向钻孔群14组,完成钻孔91个、分支孔318个,平均抽采浓度为40.71%,平均纯瓦斯流量为7.26 m^3/min,瓦斯抽采率达到26.73%,满足81309工作面回采、83109运输巷和83110回风巷掘进对瓦斯抽采的需求,充分发挥了集束型枝状定向钻孔群集中高效抽采和超前抽采的优势,在工作面圈闭之前,实现了工作面和待掘巷道的瓦斯超前治理。

According to the elimination outburst needs of working face mining and tunnel driving, elimination outburst of two places with one hole technology of cluster-type multi-branch directional hole group is proposed, and the definition and basic principle, layout and construction technology is introduced. Combined with the characteristics of coal in Baode Mine, such as large thickness, hard quality, multi-layer, poor air permeability and gas pressure, the key drilling technologies are developed, such as measurement while drilling technology, drilling trajectory with drilling manual control technology, multi-branch directional hole construction technology, and the directional drilling rig, MWD system, helical screw motor, drill rod and directional drill are developed. The field test was carried out in 81309 working face of Baode Mine, 14 cluster-type multi-branch directional hole groups, 91 drilling holes, 318 branch holes were completed, the average extraction concentration was 40.71%, the average pure gas flow was 7.26m3/min, the gas drainage rate reached 26.73%, which meets the demand of gas extraction in 81309 working face, 83109 transportation roadway and 83110 return air way. With the efficient drainage and pre-drainage of cluster-type multibranch directional hole group, the gas in working face and tunnel would be controlled advanced.