瓦斯抽采钻孔喷涂式封孔技术

Spray sealing technology for gas extraction drilling

  • 摘要: 瓦斯抽采钻孔封孔质量是影响瓦斯抽采及消突效果的关键因素。针对当前被动式封孔质量差、钻孔抽采瓦斯浓度低,主动式封孔过程繁琐等问题,提出了一种瓦斯抽采钻孔喷涂式封孔技术。钻孔施工完成后,将气动深孔离心喷杯式高转速喷头送入钻孔预设位置,同时启动封孔材料预热系统,待喷涂式封孔材料温度稳定在70~80 ℃时,打开气动式吸料泵,将封孔材料吸入并通过喷头混合喷出,使其固化于钻孔内壁;通过四象限位滑道结构系统引导喷头自孔底向孔口移动,完成喷涂式封孔作业;在钻孔口用聚氨酯发泡材料固定2.0~3.0 m的PVC堵头,而后连接抽采系统即可。现场应用效果表明:新型喷涂式封孔材料具有液态速凝、密封性好、黏结性强、阻燃、高韧性、高强度等优点,可在瓦斯抽放钻孔内快速反应、固化,并生成高强度、高韧性的阻燃密封薄膜;利用喷涂式封孔工艺及装置能实现煤层钻孔自动化密封;与聚氨酯封孔技术相比,采用喷涂式封孔技术后瓦斯抽采体积分数提高了19%,单孔封孔成本节约了53%,单孔封孔时间节省了50%。

     

    Abstract: The sealing quality of extraction drilling is the key factor affecting gas extraction and outburst elimination. In order to solve the problems of poor quality of passive hole sealing, low gas concentration in drilling and extraction, and cumbersome process of active hole sealing, a spray sealing technology for gas extraction drilling is proposed. After the drilling construction is finished, a pneumatic deep-hole centrifugal spray cup type high-rotation speed spray nozzle is sent to the preset position of the drilling hole, and a hole sealing material preheating system is started at the same time. When the temperature of the spray type hole sealing material is stabilized at 70-80℃, a pneumatic suction pump is started to suck the sealing material, and the sealing material is mixed and sprayed out through the spray nozzle and solidified on the inner wall of the drilling hole. The four-quadrant slide structure system guides the nozzle to move from the bottom of the hole to the mouth of the hole to complete the spray-type sealing operation. Finally, the PVC plug of 2.0-3.0 m is fixed with the polyurethane foam material at the drilling hole, and then the extraction system is connected. The field application results show that the new spray sealing material has the advantages of liquid quick setting, good sealing performance, strong adhesion, flame retardant, high toughness and high strength, etc. It can react and solidify quickly in the gas extraction hole, and form a flame retardant sealing film with high strength and toughness. The use of spray sealing technology and equipment can realize automatic sealing of coal seam drilling. Compared with polyurethane sealing technology, the volume fraction of gas extraction after applying spraying-type sealing technology is increased by 19%, the cost of single-hole sealing is saved by 53%, and the sealing time of single-hole is saved by 50%.

     

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