淮北矿区井下钻冲护一体化水力增透技术试验研究

Experimental study on integrated drilling， punching and protection technology for permeability enhancement in Huaibei mining area

摘要:

目前采用水力冲孔增透是碎软低渗煤层强化瓦斯治理的一种有效手段。针对淮北矿区煤层渗透性差、钻孔抽采率低、抽采周期长等问题，提出了钻冲护一体化水力造穴增透瓦斯抽采技术，开展了钻冲护一体化造穴装置研究。利用该造穴装置，配套大通径螺旋钻杆和可开闭式钻头，实现井下瓦斯抽采穿层钻孔钻进成孔、水力冲孔造穴增透和不提钻下筛管护孔工艺流程的一体化施工工艺，该工艺全过程只需下一次钻，工艺流程简单、辅助工作量小、综合效率高。在杨柳矿开展了现场试验，施工完成29个钻孔，试验结果表明：钻冲护一体化工艺技术可实现钻孔、水力造穴、筛管护孔的一体化施工，避免二次下钻再下筛管护孔，有效提高了全流程施工效率；钻孔穿煤段水力冲孔后平均冲煤量达到1.1 m³/m，平均造穴直径0.93~1.00 m，极大地提升了碎软煤层造穴增透效果。

Abstract:

Hydraulic punching to enhance permeability is an effective means of strengthening gas governance in soft and low-permeability coal seams. In response to the problems of poor permeability of coal seams， low gas extraction rate of drill hole， and long extraction cycles in the Huaibei mining area， integrated drilling， hydraulic punching and protection technology for permeability enhancement has been proposed. Research on the integrated drilling， punching and protection device has been carried out. With the use of this device， matched with large hole triangular spiral drill rods and on-off type drill bit， the integrated construction process of drilling hole， hydraulic punching for permeability enhancement， and screen pipe completion is achieved. The entire process of this technology only requires one drilling， and experiments have been carried out in Yangliu mine， and successfully drilling 29 holes. The experimental results show that the integrated drilling， punching and protection technology can achieve the integrated construction of drilling， hydraulic drilling， and screen pipe protection， avoiding the need for secondary drill pipe run for screen pipe completion， effectively improving the overall construction efficiency. After hydraulic punching through the coal section， the average volume of coal flushing reached 1.1m³/m， and the average hole diameter reached 0.93~1.0m， greatly improving the permeability enhancement effect in fragmented soft coal seams.