Integrated enhanced coal seam gas drainage system and extraction method

Abstract

The invention discloses an integrated enhanced coal seam gas drainage system and a drainage method. The pulse microwave generation system and the pulse hydraulic system are combined. The microwave radiation can reduce the tensile strength of coal and rock, and deepen the groove depth of pulse hydraulic cutting. Accelerate the slotting speed, the existence of slots can control the direction of crack propagation produced by hydraulic fracturing, and at the same time, the cracks produced by microwave radiation on the expansion of coal and hydraulic fracturing under the guidance of slots can expand each other Through penetration, the air permeability of the coal seam is increased, and the gas extraction volume of the coal seam is increased. With the change of the pulse direction, the hydraulic measures and the microwave alternately act on the coal body, and the cracks expand in a wider range, avoiding the damage of the drill bit caused by repeated hydraulic cutting. Damage, a small amount of high-pressure water action each time, makes microwave heating faster, and avoids the coal seam water lock effect caused by high-pressure water 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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