Underground coal mine coal seam hydraulic fracturing-cutting coupling permeability-improving method

Abstract

The invention relates to an underground coal mine coal seam hydraulic fracturing-cutting coupling permeability-improving method. The underground coal mine coal seam hydraulic fracturing-cutting coupling permeability-improving method comprises the following steps that 1, coal and rock parameters are actually measured on site, and all numerical simulation parameters are determined; 2, numerical simulation is conducted on coal seam hydraulic fracturing, and on-way resistance change and the peak value area distance of high-pressure water spreading in coal and rock holes and fractures are analyzed;3, hydraulic fracturing drilling positions and hydraulic cutting drilling positions are arranged according to the peak value area distance; 4, drilling, hole sealing and hydraulic fracturing permeability-improving construction are conducted at the hydraulic fracturing drilling positions; 5, after hydraulic fracturing permeability-improving construction is completed, a high-pressure pump station device of hydraulic fracturing permeability-improving equipment is moved to the hydraulic cutting drilling positions to conduct drilling, after pressure relief of a drill hole, hole sealing is conducted, and hydraulic cutting permeability-improving construction is conducted; and 6, the high-pressure pump station device of the hydraulic fracturing permeability-improving equipment is moved to the hydraulic fracturing drilling positions, and the step 4 is repeated till permeability-improving construction of a whole mine is completed. According to the underground coal mine coal seam hydraulic fracturing-cutting coupling permeability-improving method, the coal seam permeability-improving effect is greatly improved.

Description

technical field [0001] The invention belongs to the technical field of gas drainage in coal mines, and relates to a hydraulic pressure-cut coupling anti-permeability method for underground coal seams in coal mines. Background technique [0002] It is well known that the most effective way to prevent and control coal mine gas disasters is to conduct borehole gas drainage, and the permeability of coal seams is the main controlling factor restricting the rate of borehole gas extraction. The coal seam is dominated by natural gas, which seriously affects the effect of gas drainage. According to previous studies, hydraulic fracturing and hydraulic slotting are the most mature measures currently used in underground coal seam permeability enhancement measures in coal mines, and have been widely promoted and applied as a high-efficiency gas drainage and gas disaster control technology. However, hydraulic fracturing and hydraulic slotting anti-permeability technologies have their own...

AI Technical Summary

Problems solved by technology

However, hydraulic fracturing and hydraulic slotting anti-permeability technologies have their own limitations: hydraulic fracturing has a better anti-permeability effect in hard coal seams, but in soft coal seams, high-pressure water often destroys the coal and rock mass around the borehole. , resulting in coal seam fissures being damaged by high stress, or even closed. If hydraulic fracturing uses lower water pressure, the influence range of coal and rock mass permeability enhancement is small

Coal seam hydraulic slotting anti-permeability technology can effectively promote gas analysis and migration in soft coal seams, and improve gas extraction rate, but during the implementation of slotting, it will form an instantaneous strong shock wave that acts on the coal seam, which is difficult to control, and can easily induce blowout holes, Holding drills, even producing coal and gas outbursts

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