Mine Rock Mass Drilling Multi-stage Gas Drainage Method

Abstract

The invention discloses a mine rock mass borehole multi-section type gas extraction method. The problem that in the prior art, the borehole sealing effect is poor is solved, and the advantages of being good in sealing effect and easy to operate are achieved. According to the scheme, the method comprises the steps that a mine rock mass drilling multi-section type gas extraction testing probe is adopted, wherein the testing probe comprises at least three first sealing units and a second sealing unit, wherein two first sealing units are arranged at the two ends respectively, the first sealing unit at the head end is connected with a cone head, two adjacent first sealing units between the middle first sealing unit and the first sealing unit at the head end are connected through a collecting pipe, a plurality of second holes with one-way sealing parts are formed in the side wall of the collecting pipe, the second sealing unit is arranged between the first sealing unit at the tail and the middle first sealing unit, a communicating pipe is arranged between the second sealing unit and the first sealing unit at the tail, side leakage valves are arranged on one side of the second sealing unit and used for sealing cracks of boreholes between the first sealing unit at the tail and the side leakage valves and surrounding rock mass.

Description

technical field [0001] The invention relates to the technical field of mine rock mass drilling and extraction, in particular to a mine rock mass drilling multi-stage gas extraction method. Background technique [0002] Gas is a harmful factor in coal mine production. It not only pollutes the air, but when its content increases, it will explode in case of fire. Gas is a mixed gas composed of methane, carbon dioxide and nitrogen escaping from coal and surrounding rocks. Gas pressure and Gas content is an important parameter to indicate the state of coal seam gas occurrence. The measurement of coal seam gas pressure and gas content is not only helpful to study the law of coal seam gas occurrence and gushing, but also gas drainage can turn harm into benefit and be developed and utilized as coal-associated resources. In the prior art, a set number of boreholes are usually drilled on the coal body, and the extraction is carried out through a vacuum pump. During the extraction pro...

AI Technical Summary

Problems solved by technology

[0003] 1) The structure of the plugging device in the pipeline is complex, which makes assembly difficult, and easily leads to the backflow of the plugging medium, which in turn affects the plugging rate;

[0004] 2) It is impossible to set the plugging of the borehole outside the collection pipe, and if the borehole can be blocked, it cannot guarantee the orderly plugging of the borehole plugging and the borehole cavity outside the collection pipe, and the drilling hole cannot be guaranteed. Internal sealing quality;

[0005] 3) The gas drainage pipeline and the plugging pipeline in the borehole are independent of each other, and there are many pipelines (generally 2 to 3) that are prone to pipeline entanglement, which not only has low sealing efficiency, troublesome operation, but also poor stability;

[0006] 4) Moreover, the setting of multiple pipelines in the prior art causes the drainage operation method to be complicated and difficult to operate;

[0007] 5) Most of the plugging media are solid media. After solidification, cracks are prone to occur or the solid material cannot seal the cracks in the rock mass around the drilling wall of the corresponding section, and the two-stage sealing method is often used, and the sealing effect is poor;

[0008] 6) Traditional gas drainage systems are mostly disposable consumables, which generally cannot be reused, which increases the cost of gas drainage;

[0009] 7) Most of them are single-stage structures, which are sealed at both ends of the drainage pipe. If it is too long, the borehole in the middle will easily collapse and affect the drainage effect. If it is too short, the gas drainage range of each rock mass drilling hole will be small , for deep gas extraction, other drilling is required, which will undoubtedly further increase the cost of extraction

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