“Y”型通风沿空留巷下向穿层钻孔瓦斯抽采技术

Gas Drainage Technique by Downward Through Bed Hole of Y- shape Ventilation Gob- side Entry Retaining

"Y"型通风沿空留巷是治理煤层群瓦斯隐患的可靠方式,实现了沿空留巷下向钻孔在工作面回采前后连续进行瓦斯抽采,达到沿空留巷"一巷多用"的目的。对下向钻孔的施工方式进行了改进,并利用泥浆排渣方法,大幅提高了排渣效率及成孔率。研究发现,应避开工作面超前应力集中区域和回采覆岩移动影响范围,以获得较好的成孔效果。为获得较好的抽采效果,在布置下向抽采钻孔进行瓦斯抽采时,应使钻孔的终孔位置与巷道之间的距离大于10 m。

Gob-side entry retaining of Y-shape ventilation is a reliable method to control gas from coal seams. In this paper, downward through bed holes from gob-side entry retaining of Y-shape ventilation are used to continuously control gas from coal seams, and get the purpose of ＂one retained entry, multi-functions＂. The drilling method of boreholes is improved, and mud water is used to get cuttings out, and this greatly improves effect of removing cuttings and decreases defective rate of boreholes. The results show that the stress concentration zone should be avoided to decrease defective rate of boreholes; and in order to acquire high effect of gas drainage with downward through bed hole, the distance between crosshead and the rear end of borehole should be greater than 10 m.