Integrated reinforced coal seam gas extraction system and extraction method

Abstract

The invention discloses an integrated reinforced coal seam gas extraction system and an extraction method. A pulse microwave generation system and a pulse hydraulic system are combined, the tensile strength of coal rock can be reduced through microwave radiation, the depth of a seam groove for pulse hydraulic cutting is increased, the seam cutting speed is increased, and the crack propagation direction generated by hydraulic fracturing is controlled to a certain extent due to the seam groove; meanwhile, cracks generated by coal body reaming and crack forming and cracks generated by hydraulic fracturing under the guiding effect of the seam groove can be mutually expanded and communicated through microwave radiation, the gas permeability of a coal seam is improved, and the coal seam gas extraction amount is increased; along with the change of the pulse direction, hydraulic measures and microwaves alternately act on a coal body, the crack propagation range is wider, and damage to a drill bit due to continuous repeated hydraulic seam cutting is avoided; and a small amount of high-pressure water acts each time, so that microwave heating is faster, and the coal seam water locking effect caused by the high-pressure water is avoided to a greater extent.

Description

technical field [0001] The invention belongs to the field of coal mine gas prevention and utilization, is applied to high gas, low permeability and hard coal seams, and is specifically an integrated enhanced coal seam gas drainage system and a drainage method. Background technique [0002] Gas drainage is the most effective way to control gas disasters, but the gas permeability of coal seams restricts the gas drainage rate of coal seams. The main feature of most coal seams in my country is low gas permeability. With the increase of mining depth, the gas permeability of coal seams becomes worse and worse, which seriously affects the gas drainage effect. In order to improve the gas extraction rate, the more commonly used method is to increase the gas permeability of the coal seam to increase the amount of gas extraction. The main hydraulic measures used include hydraulic cutting and hydraulic fracturing. However, when hydraulic fracturing is used alone, the depth of the slit ...

AI Technical Summary

Problems solved by technology

However, when hydraulic fracturing is used alone, the depth of the slit is limited, resulting in a small drainage radius. Only a large number of drilled holes can effectively drain the gas. However, hydraulic fracturing alone cannot control the crack initiation position and the crack expansion range. less, unable to fully desorb the gas

The existence of these problems limits the application of hydraulic fracturing and hydraulic slotting in the field. It is urgent to propose new methods to solve these limitations and improve the air permeability of coal seams.

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