Multi-stage pressure-bearing permeable hole sealing method and device

Abstract

Disclosed is a multi-stage pressure bearing permeable hole sealing method, comprising thefollowing steps: 1) performing multi-segment expansion hole sealing at a position to be sealed in a borehole, wherein the number of segments for expansion hole sealing is not less than four, and a permeable hole sealing segment is retained between adjacent expansion hole sealing segments; 2) performing multi-stage interval grouting in the permeable hole sealing segments, and retaining a permeable hole sealing segment for next-stage grouting between the permeable hole sealing segments for previous-stage grouting; and performing the next-stage grouting after the previous-stage grouting is completed, wherein the pressure of the next-stage grouting is greater than the pressure of the previous-stage grouting; and 3) after the grouting pressure of a permeable hole sealing segment for the final-stage grouting reaches a pre-determined value, completing hole sealing. Further disclosed is a multi-stage pressure bearing permeable hole sealing device. The method and the device can increase the grouting pressure on the basis of a conventional two-sealing-and-one-grouting hole sealing method, thus improving the quality of hole sealing, solving the problem of the low extraction concentration of coal mine gas, and realizing high-concentration and high-quality gas extraction from an extraction borehole in a mine.

Description

technical field [0001] The invention specifically relates to a multistage pressure-bearing permeable hole sealing method and device, belonging to the technical field of coal mining. Background technique [0002] The quality of hole sealing during coal mine gas drainage determines the degree of gas drainage. With the advancement of technology, the "two plugging and one injection" sealing method is gradually adopted at present. The specific principle is: first, the two ends of the sealing section are sealed with grouting expansion, and then the two ends are sealed through the grouting pipe. Grouting is performed on the borehole section between the plugging sections of the end pockets. Under the action of grouting pressure, the grout penetrates into the borehole wall and fills the cracks around the borehole. [0003] The advantage of the "two blocks and one injection" grouting method under pressure is that it realizes the grouting of the borehole wall, and supports the borehol...

AI Technical Summary

Problems solved by technology

However, the traditional "two blocks and one injection" sealing method is sealed with two ends of the hole, and only relies on the frictional resistance between the bag and the side wall of the borehole to seal the hole. Leakage gaps, thus unable to support large grouting pressure

The above reasons limit the "two plugs and one injection" method to further improve the sealing quality

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