Comprehensive method of drilling, permeability increasing, repairing and gas-driven displacing of drill hole underground coal mine

Abstract

The invention discloses a comprehensive method of drilling, permeability increasing, repairing and gas-driven displacing of a drill hole underground a coal mine. The comprehensive method comprises the following four process steps of drilling a drill hole, increasing the permeability of a coal bed, repairing the drill hole and increasing permeability driven by gas. The comprehensive method can be used for realizing continuous drilling and remote operating and has the advantages of being simple in construction, smooth in slagging, and quick in drilling speed and the like; an operator is far away from a construction site during a construction process, so that the labor environment of workers is improved, dangerous accidents are reduced and prevented and the personal safety of operators can be effectively guaranteed. The coal bed can be subjected to the action of the following measures such as hydraulic cutting, fracturing and punching and the like, so that the permeability coefficient of the coal bed can be greatly and uniformly improved, and stress concentration caused by hydraulic operation can be explained by following a certain pattern; and drilling repair on the existing collapsed drill hole and water accumulation drill hole can be performed, so that the service life of drill holes is prolonged, and the effective extraction quality of the drill holes is improved; and meanwhile, on the basis of increasing the permeability and repairing of the drill hole, if the later-stage extraction effect is not obvious, a gas driving process can be adopted to improve mashgas extraction efficiency.

Description

technical field [0001] The invention belongs to the technical field of coalbed methane exploitation, and in particular relates to a comprehensive method for drilling, anti-reflection, restoration and gas drive replacement of boreholes in coal mines. Background technique [0002] my country's coal mine gas disaster is serious, seriously restricting the safe production of coal enterprises. Gas drainage is currently the main technical means for gas control in my country. However, due to the softness and complex occurrence of coal seams in my country, there are drill sticking, top drilling, drill drop, and difficulty in connecting drill pipes during the drilling process. Such phenomena restrict the drilling speed and quality of coal seam drilling; the gas permeability coefficient of coal seam plays a decisive role in the gas drainage effect, and most of the high-gas outburst mines in my country are low-permeability coal seams, which determine the quality of most mines in my count...

AI Technical Summary

Problems solved by technology

[0004] The key to coal seam gas control in my country lies in the enhancement of coal seam permeability. At present, coal seam enhancement is mainly based on hydraulic measures, such as hydraulic fracturing, hydraulic punching, hydraulic extrusion, high-pressure water injection, etc. In addition, there are loosening blasting, air replacement, etc. Although certain achievements have been made, due to the complexity of technical applications (uneven opening of cracks, chaotic stress concentration, etc.) Promote application

[0005] Due to the influence of overburden rock pressure, mining stress, gas pressure, coal seam fissure water, coal structure, strength and other factors, as time goes by, the drainage borehole will collapse and accumulate water to varying degrees. problems, resulting in low extraction efficiency or even abolishment, seriously affecting the mine's outburst reduction plan and production deployment

In order to solve the problem of borehole collapse and water accumulation after long-term extraction, at present, high-pressure air (mine air pressure pipe for air supply, wind pressure ≤ 0.7MPa) is used to discharge slag and penetrate holes mainly by pressing into the borehole. Drilling at a depression angle with a hole length of less than 15m and an inclination angle of less than 10° can achieve certain results. Due to the limited pressure values ​​of water pressure and wind pressure, the purpose of slag discharge and penetrating holes cannot be achieved for drilling with a large hole length and a large inclination angle.

At the same time, there is no tool with a certain strength that can continuously drill into the collapsed borehole. Therefore, the penetration efficiency is low, and the borehole is often rebuilt to make up for it.

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