Underground coal mine drilling, heat injection and hole sealing integration method

Abstract

The invention provides an underground coal mine drilling, heat injection and hole sealing integration method suitable for drilling, high-pressure heat injection and hole sealing. The method is characterized in that multiple disc-shaped slots are cut in a bottom plate rock stratum through high-pressure jet flow; a plastic sleeve is fed into a drilled hole, and grout is injected into the portion between the wall of the drilled hole and the outer wall of the plastic sleeve; after the grout is condensed, a heat injection pipe is fed into the sleeve for heat injection; after heat injection is finished, the heat injection pipe is withdrawn, two polyurethane reaction bags are arranged at the end, close to a coal bed, of the drilled hole, and the portion between the two bags is filled with a heat insulating material; grout is injected into the opening end of the drilled hole, and then hole sealing is finished. The method has the advantages of being capable of insulating heat, resistant to high pressure, high in sealing degree and the like, the problems that hole sealing fails and gas leaks from hole wall cracks due to heat loss and high pressure in the heat injection process can be effectively solved, the heat injection pipe can be recycled, and heat injection cost is low.

Description

technical field [0001] The invention relates to an integrated method of heat injection and hole sealing for underground drilling in coal mines, and is especially suitable for high-pressure heat injection and hole sealing for drilling. Background technique [0002] Aiming at the problems that my country's coal seams generally have the characteristics of microporosity, low permeability, and high adsorption, which result in low coal seam permeability and difficult gas extraction, the patent application CN201410404943.0 (a gas explosion-induced fracturing coal mass strengthening in drilling holes) Drainage method) proposes to premix the gas gushing out of the borehole with air and detonate to form an explosion shock wave to crack the coal body, and at the same time, the thermal effect of the explosion can promote the desorption and flow of gas, so as to achieve the purpose of strengthening coal seam gas drainage . Patent application 200810079794.X (method for extracting coalbed m...

AI Technical Summary

Problems solved by technology

At present, the steel heat injection pipes used in coal seam heat injection to enhance gas drainage are basically unable to be recycled, resulting in high heat injection costs and burying safety hazards for later coal seam recovery

In addition, the serious gas leakage in the cracks of the borehole wall currently leads to the low concentration of borehole gas extraction, and even leads to the spontaneous combustion of coal in the borehole, which needs to be solved urgently

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