Device and method for enhancing coal seam fracturing effect

Abstract

The invention discloses a device and method for enhancing a coal seam fracturing effect. The device comprises four parts, namely, a connecting rod, a connecting sleeve, an expandable sleeve and a constant-pressure switch; a drilling site is arranged according to a full mechanized mining face and coal seam occurrence conditions, all parts are assembled into a system in sequence according to a figure 1 based on drilling site parameters and the coal seam occurrence conditions, the system is arranged between two hole packers and is connected with a water injection pipe, and then, a high-pressure water injection fracturing process is started. According to the device, the number of hole wall cracks can be increased, the device can be used for changing hydrostatic pressure into pulse loads for injected high-pressure water, so that the crushing degree of rocks is enhanced, the crack density is increased, and the hydrostatic pressure can be used for increasing the lengths of the cracks. The invention aims to increase the air permeability of the coal seam, solve the problem of difficult drainage in low-air-permeability coal seams, and increase the gas drainage rate of the coal seams. The device has the advantages of simplicity, clear concept and convenience in operation.

Description

technical field [0001] The invention relates to the problem of coal seam gas drainage, in particular to a device for increasing the cracking effect of coal seams. Background technique [0002] In recent years, with the increase of mining intensity and mining depth, the coal seam gas content and mine gas emission are getting higher and higher. There are more and more gas accidents caused by this. Gas disaster has become one of the most serious disasters in mine production. There are many technologies to prevent gas accumulation beyond limit and coal and gas outburst, among which coal seam gas pre-drainage is an important technical measure widely used at home and abroad. [0003] At the same time, my country's coalbed methane resources are extremely rich. According to estimates, its resources are about 42×10 12 ㎡, ranking second in the world, equivalent to conventional natural gas resources, and basically distributed along the West-East Gas Pipeline, with huge exploitation ...

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Problems solved by technology

[0006] The purpose of the present invention is to solve the above-mentioned technical problems existing in the prior art, and to provide a device and method for increasing the cracking effect of coal seams. Connect the coalbed methane in the structural plane, solve the problem of difficult drainage of low-permeability coal seams, and improve the drainage rate of coalbed methane

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