A powder particle-high grouting pressure sealing device and method for gas drainage drilling and sealing cracks

Abstract

The invention provides a powder particle-high-pressure grouting crack packing gas extraction drilling and sealing device and method. The powder particle-high-pressure grouting crack packing gas extraction drilling and sealing device and method is applicable to underground coal mines. The powder particle-high-pressure grouting crack packing gas extraction drilling and sealing device comprises an outer bag and an inner bag, wherein the rear of the outer bag is provided with a fixing unit on a gas extraction pipe; the inner bag is provided with a screen pipe, a bag grouting pipe and a grouting pipe which penetrate through the fixing unit, the tail portions of the screen pipe, the bag grouting pipe and the grouting pipe are arranged at the rear of the outer bag, and the tail ends of the screenpipe, the bag grouting pipe and the grouting pipe are provided with valves; quick lime powder coerced by carbon dioxide is guided into the space among packing materials via the screen pipe to block fractures around a drilled hole through reaction products; cement mortar is filled in by the grouting pipe to achieve the aim of packing cracks and actively supporting the drilled hole. Therefore, thepowder particle-high-pressure grouting crack packing gas extraction drilling and sealing device can effectively reduce the influence of mining damage, prolong the effectively extraction period of drilling gas extraction, increase the concentration of extracted gas, maintain stability of the drilled hole, significantly improve the coal seam gas extracting effects and ensure safety of underground workers.

Description

technical field [0001] The invention relates to a hole sealing device and method for gas drainage drilling, in particular to a gas drainage drilling sealing device and method for sealing cracks with powder particles and high grouting pressure. Background technique [0002] In underground coalbed methane extraction, after the formation of gas boreholes, if only relying on the seepage and diffusion of gas in the coal seam, the extraction efficiency is not ideal, so it is often necessary to improve the extraction efficiency by means of extraction negative pressure. However, the rock / coal body is a structural body, and there are fracture groups inside. Therefore, under the negative pressure of extraction, air often mixes into the borehole through the fracture groups and the plugged fractures at the bottom of the hole. At the same time, under the influence of mining and drilling, the primary fracture group will redevelop. In the depth of the borehole, the redevelopment of the fr...

AI Technical Summary

Problems solved by technology

However, the powder filled in the borehole has a rigidity problem, which cannot play an active support role very well, but can only play a passive support role.

Moreover, this method mainly relies on the negative pressure of extraction to make the powder in the borehole enter the fissures. Therefore, not all the fissures around the borehole are sealed, but only the connected fissures are blocked. After damage, previously unconnected fissures may become connected

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