低浓度抽采钻孔压缩空气循环脉冲疏堵增透技术研究

针对瓦斯抽采过程中存在的透气性低、钻孔堵塞，引起瓦斯流动通道封闭造成的瓦斯抽采浓度低等问题，通过研究压缩空气循环脉冲疏堵增透机理，优化关键技术参数，研制基于压缩空气循环脉冲动力作用的抽采钻孔自动疏堵增透装置，并进行现场工业试验。研究结果表明：利用压缩空气循环脉冲装置对钻孔疏堵增透后，能将钻孔内的堵塞物破碎运出钻孔，并在抽采钻孔周围煤体中形成新的裂隙。疏堵前后，典型代表性钻孔瓦斯浓度最大变化倍数8.3，平均变化倍数5.2。纯流量最大变化倍数24.18，平均变化倍数11.6，明显提高了低浓度瓦斯钻孔的抽采效果。

Study on the technology of high pressure gas circulation pulse plugging and enhancing permeability in low concentration drilling

It is the key of safe and efficient production to improve the extraction effect of gas extraction borehole. Based on the analysis of the reasons for the attenuation of gas concentration in the borehole, the mechanism of plugging and increasing permeability of high-pressure gas circulation pulse is studied, and a high-pressure gas circulation pulse plugging and increasing permeability device is developed. The field industrial test was carried out in No.12 coal mine of PingdingshanTian'an Coal Industry Co., Ltd. to establish a repeatedly acting pressurized and depressurized aerodynamic field in the extraction borehole, tear and destroy the coal slag blocking the borehole, and transport it out of the borehole. At the same time, depending on the hysteresis and tensile failure of the coal adsorption deformation, a new crack was formed in the coal around the extraction borehole and the gas flow was opened Moving channel. The results show that the technology of high pressure gas circulation pulse plugging and permeability enhancement has achieved the goal of improving the concentration and flow of gas extraction, and provided equipment and technical support for the safe and efficient production of coal mine.