松软煤层中风压空气钻进技术与装备

松软煤层中施工顺层瓦斯抽采长钻孔的难度大,现有技术、装备在一定程度上还存在成孔深度浅、成孔率低等问题,不能完全满足瓦斯高效抽采的需要。为此,开发了井下中风压空气钻进工艺技术:包括压缩空气与螺旋钻杆复合排渣工艺、多级除尘技术、筛管护孔工艺技术等。应用结果表明:在同等施工条件下,采用中风压空气钻进技术与装备后,平均成孔深度普遍提高1倍左右,钻进效率提高35%左右,成孔率提高到了70%左右,为松软煤层瓦斯抽采钻孔施工提供了可靠的技术与装备保障。

Medium Wind Pressure Air Drilling Technique and Equipments in Soft Coal Seam

It is difficult to drill bedding long borehole for gas extraction in soft coal seam.The available drilling technology and equipments with the problems of shallow borehole depth and lower hole-forming ratio can't meet the demand of gas efficient extraction.Therefore,the medium wind pressure air drilling technique for soft coal seam was developed,which included compound exhausting slag technique with compressed air and helix drilling rod,multistage dust collection technique and protecting hole technique with screen liner.The application results showed that the average borehole depth generally increased by one time,the drilling efficiency was enhanced about 35 percent,and the hole-forming ratio reached 70% after using pressure air drilling technology and equipment under the same construction conditions,which provided a reliable technology and equipment support for the construction of gas extraction borehole in soft coal seam.