Hydrofracturing-based method and equipment for diminishing dust and eliminating outburst of coal bed

Abstract

The invention discloses a hydrofracturing-based method and hydrofracturing-based equipment for diminishing dust and eliminating outburst of a coal bed. The method comprises the following steps of: firstly, drilling a long hole towards a working surface in a return airway of the coal-excavating working surface, sealing the hole with a hole sealer for hydrofracturing and forming a hydrofractured seam in the coal rock body; secondly, adding sand into a sand mixer and conveying the mixed fluid of water and sand into the hydrofractured seam by using a mud sand pump, wherein thin sand is added first and then thick sand is added; thirdly, connecting a mash gas extracting pipeline to the hydrofractured hole, draining water through negative pressure and extracting mash gas; and finally, removing the mash gas extracting pipeline from the hole sealer, and connecting a static-pressure water-injecting pipeline for performing static-pressure water injection into the coal bed after the hydrofracturing and the mash gas extraction and stopping water injection till the water flows to the position 3 to 5m ahead of the coal wall of the working surface. By employing the expansion of the main hydrofractured seam of the coal bed, the expansion of wing-shaped branched seams and the soaking effect of the absorbed water, the structure of the coal bed is changed, the strength of the coal bed is weakenedand the permeability of the coal bed is improved, so the aims of weakening the strength of the coal bed, increasing the permeability of the coal bed, eliminating the outburst and diminishing the dustare achieved.

Description

technical field [0001] The invention relates to a coal mine outburst reduction method and equipment, in particular to a coal seam dust reduction and outburst reduction method and equipment based on hydraulic fracturing to weaken coal seam strength, increase permeability, eliminate outbursts, and reduce dust. Background technique [0002] The prevention and control of rock burst in coal mines, the weakening of hard top coal, the enhancement of gas-bearing coal seams, the prevention and control of coal and gas outbursts, and dust reduction have always been important issues in the coal mining process. To solve the above problems, the existing methods have a single effect, and cannot achieve comprehensive prevention and control of rock burst prevention, hard top coal weakening, gas-containing coal seam permeability enhancement, coal and gas outburst prevention, and dust reduction. For example, the traditional gas extraction method is to drill dense and long boreholes in the coal...

AI Technical Summary

Problems solved by technology

To solve the above problems, the existing methods have a single effect, and cannot achieve comprehensive prevention and control of rock burst prevention, hard top coal weakening, gas-containing coal seam permeability enhancement, coal and gas outburst prevention, and dust reduction.

For example, the traditional gas extraction method is to drill dense and long drill holes in the coal and rock formations, and then directly extract the gas. The drill holes are deep and dense, resulting in cumbersome construction and unsatisfactory extraction effects, which cannot be effectively comprehensively controlled.

For example, in the past, there was also a method of using coal seam water injection to prevent coal mine rock burst, but the water injection pressure was too small, so the effect was not obvious, and the dust reduction effect was even worse.

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