Full-cycle strict hole sealing structure of gob-side entry extraction drilling hole

Abstract

The utility model discloses a kind of along empty roadway extraction borehole full cycle strict hole sealing structure, belong to coal mine gas extraction engineering technical field.Aiming at the problems such as insufficient shallow grouting pressure, hole sealing section is vulnerable to stress shear damage, pipe bottom hole collapse plugging and lack of failure remedial measures in existing two-plugging one-injection hole sealing structure in along empty roadway, full cycle sealing scheme is proposed.The structure divides extraction borehole into pressure-relief section and primary hole sealing section, pressure-relief section is left empty as deformation buffer, primary hole sealing section is deeply placed at more than 11 meters from roadway coal wall to avoid stress peak area, and forms grouting area by two hole sealing capsules;It is also provided with secondary grouting precision plugging area and later three-plugging two-injection reinforcing structure.The structure can actively avoid harmful stress area, realize mid-term dynamic maintenance and later whole-hole strengthening, significantly improve hole sealing reliability and extraction concentration, prolong borehole life and reduce hole repair cost.

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