An integrated outburst prevention method for regional gas control with drilling, blasting and pumping

Abstract

An integrated outburst prevention method for regional gas control, drilling, blasting, pressure extraction, first constructing a blast hole and four control holes from the roof roadway or floor roadway of the coal seam to the coal seam in the outburst prevention area, and blasting the blast hole and injecting water Determine the distance between blast holes, control holes and water injection holes; construct multiple blast holes, multiple control holes and multiple water injection holes alternately in the outburst prevention area according to the set spacing, and after blasting the blast holes, inject Inject pressure water into the water injection hole. When the water pressure reaches a certain pressure, keep the pressure for a period of time. When the water pressure decreases with the expansion of the crack, increase the water injection pressure again. Repeat this cycle for many times until the water injection pressure is completely stable. Stop water injection. Periodic drainage is implemented in this area. It can control the direction of hydraulic fracturing, avoid disorderly fracturing, eliminate the stress concentration caused by simple hydraulic fracturing technology, and realize the overall pressure relief of coal and rock mass, and finally eliminate the risk of outburst.

Description

technical field [0001] The invention relates to an integrated outburst prevention method for regional gas control, drilling, blasting, pressure extraction, and is particularly suitable for eliminating the outburst risk in high gas and low permeability outburst dangerous coal seams. technical background [0002] Due to the difficulty of gas drainage in high-gassy and low-permeability coal seams, a large amount of gas will be gushed out during the mining process, and coal and gas outburst accidents often occur. It is becoming more and more serious, restricting the safe production of coal. The current technology mainly focuses on depressurization and permeability enhancement of coal and rock mass, but the biggest problem with traditional technology is that the decompression area is small, and stress concentration is often accompanied by decompression. Currently, the pressure relief and anti-outburst measures for low-permeability outburst coal seams mainly include deep-hole loo...

AI Technical Summary

Problems solved by technology

[0002] Due to the difficulty of gas drainage in high-gassy and low-permeability coal seams, a large amount of gas will be gushed out during the mining process, and coal and gas outburst accidents often occur. It is becoming more and more serious, restricting the safe production of coal

The current technology mainly focuses on depressurizing and increasing the permeability of coal and rock mass, but the biggest problem with the traditional technology is that the decompression area is small, and the decompression is often accompanied by the generation of stress concentration

Currently, the pressure relief and anti-outburst measures for low-permeability outburst coal seams mainly include deep-hole loosening blasting, deep-hole controlled blasting, and water jets. problems such as long time

Although the controlled blasting technology can relieve the pressure of the coal and rock mass and discharge gas to a certain extent, since the cracks from the blasting hole to the control hole are not obvious after blasting and will close in a short period of time, in It is more serious in soft coal seams, which affects the use of controlled blasting technology

Hydraulic fracturing technology can achieve pressure relief in a large area relatively speaking, but it also produces high stress concentration during pressure relief. The concentrated stress can reach about 3 to 4 times the original stress, which creates new obstacles to the safe production of coal mines.

In addition, the fracturing direction of the hydraulic fracturing technology is not controlled, and it is a disorderly fracturing, which often causes multiple fracturing in the pressure relief area, and the stress concentration in the stress concentration area is greater. This is also proved by a prominent accident, so hydraulic fracturing technology has great safety hazards in the process of engineering use, which limits the use of this technology

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