Method for treating low air permeability coal seam gas discharge

Abstract

The invention discloses a method for treating low air permeability coal seam gas discharge. According to the method, holes are bored in a coal seam of a coal face, and coal seam fracturing is carried out through a borehole expansion agent to increase the coal seam air permeability for gas discharge. The method comprises the following steps: firstly, forming the boreholes in the coal seam according to the degree of freedom and the hardness of the coal seam; secondly, preparing the borehole expansion agent according to different coal seam temperatures and the characteristics of the borehole expansion agent; thirdly, purging residual coal slag and water in the boreholes in the coal seam to be clean through high-pressure air, and pressing the expansion agent into the boreholes through an extrusion pump or a grout pump to break the coal seam after the reaction of the expansion agent; finally, fracturing the coal seam through the explosion agent to increase the coal seam air permeability, thereby reducing the gas concentration.

Description

technical field [0001] The invention relates to a gas discharge technology, in particular to a method for treating gas discharge from low-permeability coal seams. Background technique [0002] Coal and gas outburst is one of the important causes of accidents in coal mine production process. With the extension of coal mining level, the ground stress increases and the gas pressure rises, resulting in gas accumulation in local areas, the danger of coal and gas outburst is becoming more and more serious, and the difficulty of gas prevention and control is also becoming more and more difficult. Gas pumping and drainage (gas drainage and gas discharge) are one of the main technical measures to prevent and control gas, but for low-permeability coal seams, the effect of gas pumping and drainage is poor, and the purpose of gas control cannot be achieved. Now commonly used gas anti-reflection technologies mainly include: hydraulic slit enhanced drainage technology, deep hole controll...

AI Technical Summary

Problems solved by technology

Gas pumping and drainage (gas drainage and gas discharge) are one of the main technical measures to prevent and control gas, but for low-permeability coal seams, the effect of gas pumping and drainage is poor, and the purpose of gas control cannot be achieved

Now commonly used gas anti-reflection technologies mainly include: hydraulic slit enhanced drainage technology, deep hole controlled blasting technology, rotary hydraulic reaming technology, intensive long drilling technology, etc. The problem of high rate of exceeding the standard, and the operation in the coal mining face often brings safety hazards, damages equipment, easily induces coal and gas outbursts, and causes serious disasters. In order to avoid these hidden dangers, some safety measures must be added, which increases supply and demand. cost, affecting productivity

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