Drilling, cutting, pressing and pumping method

Abstract

The invention provides a drilling, cutting, pressing and pumping method which is suitable for gas extraction of coal seams which are high in gas and low in gas permeability. The drilling, cutting, pressing and pumping method comprises punching a drill hole according to the design requirements through a drilling machine; replacing a hydraulic seam cutting drill bit after a drill rod is withdrawn, continuing to drill to the bottom of the drill hole and withdrawing the drill rod to perform hydraulic seam cutting; sealing the drill hole and performing gas drainage after the hydraulic seam cutting is achieved; switching a drainage pipeline into a pulse water injection pump station when the gas drainage capacity is in the attenuation trend and fracturing the coal seams in a pulse hydraulic fracturing mode. According to the drilling, cutting, pressing and pumping method, the effective influence range of a single hole of gas extraction drilling of the coal seams can be increased by more than 30%, the gas flow of the single hole can be improved by more than 30%, the gas extraction rate can be improved by more than 20%, the operation is simple, the influence range of drilling pressure relief can be improved, and the concentration and the efficiency of the gas extraction of the drilling can be improved.

Description

technical field [0001] The invention relates to a method of drilling, cutting and pressure pumping, which is particularly suitable for gas pumping of high-gas and low-permeability coal seams in underground coal mines. Background technique [0002] The geological conditions of my country's coal mines are complex, high-gas coal seams account for 50-70%, and high-gas low-permeability coal seams account for about 70% of them. The mining of high-gassy and low-permeability coal seams is often accompanied by a large amount of gas gushing, especially with the efficient intensification of coal production and the increase of mining depth, the amount of gas gushing is increasing, and the threat of gas explosion and gas outburst is also increasing. Gas disasters have become the most important factor restricting the development of intensive mining technology and safe production in colleges and universities. Therefore, how to solve the problem of gas gushing in the process of mining high...

AI Technical Summary

Problems solved by technology

However, high-gassy and low-permeability coal seams have poor air permeability, and conventional drainage is difficult and ineffective, so technical measures for pressure relief and permeability enhancement are required

Conventional gas drainage methods are difficult to play a role. The main problems are: the effective range of drilling is small, the workload of drilling construction on the working face is large, and the drainage efficiency is low

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