Under-pressure grouting hole sealing device and method for gas extraction drill air bag blocking

Abstract

The invention relates to an under-pressure grouting and hole sealing device and method for gas extraction drill air bag blocking. The device is characterized in that the device comprises an extraction pipe, a first tip air bag, a second tip air bag, a slurry outlet pipe and a grouting pipe, wherein the extraction pipe is composed of a first extraction pipe body, a second extraction pipe body and a third extraction pipe body, the first extraction pipe body is sleeved with the first tip air bag, a one-way needle valve is arranged on the first tip air bag, the slurry outlet pipe with a one-way check valve arranged inside penetrates through the first tip air bag, the outer end of the slurry outlet pipe is communicated with the grouting pipe, the third extraction pipe body is sleeved with the second tip air bag, a one-way needle valve is arranged on the second tip air bag, the two ends of the second extraction pipe body are connected with one end of the first extraction pipe body and one end of the third extraction pipe body respectively, the tip of the other end of the third extraction pipe body is provided with a plurality of sieve holes which allow gas to inflow, and the first tip air bag and the second tip air bag are filled with expansion agents in advance. The device and the method can be widely applied to permanent hole sealing for coal mine underground gas extraction hole drilling.

Description

technical field [0001] The invention relates to a drilling hole sealing device and method for gas drainage in coal mines, in particular to a drilling hole sealing device and method for gas drainage drilling airbag sealing with pressure grouting. Background technique [0002] Gas drainage is one of the important ways to control coal mine gas. However, due to the complex occurrence conditions of coal seams in my country and the unsatisfactory drilling conditions, it has always been a technical problem to efficiently and tightly seal boreholes. At present, the drilling and sealing technologies for coal seam gas drainage in my country mainly include mechanical hole sealing, sealing with inorganic materials such as cement slurry, sealing with polymer organic materials such as polyurethane, and sealing holes with pressure grouting combined with various materials. . [0003] Mechanical hole sealing has high requirements on drilling quality. The hole in the sealing section must be s...

AI Technical Summary

Problems solved by technology

[0003] Mechanical hole sealing has high requirements on drilling quality. The hole in the sealing section must be smooth and free from collapse. The cost of sealing is high, and the recycling rate is low. It is only suitable for temporary quick sealing.

Sealing with inorganic materials such as cement slurry is easy to form crescent-shaped blind spots for gently inclined or near-horizontal drilling, and ordinary cement slurry is easy to shrink and form cracks after solidification, causing external air to leak in

Polyurethane and other polymeric organic materials are easy to seal, but the foaming and solidification of black and white materials is too fast after mixing, and it is easy to solidify before being sent to the predetermined position of the drilling hole, and its mechanical properties after curing cannot provide enough support for drilling , leading to a significant reduction in the extraction life due to the collapse of the hole wall and the generation of new cracks due to the shrinkage and deformation of the section

The sealing method of pressure grouting combined with multiple materials is the current main development direction. Generally, organic foam materials such as polyurethane and marisan are used to seal the two ends to form a closed space, and then inject cement slurry and other inorganic materials into it to fully Utilizing the characteristics of fast response, high expansion multiple of organic materials, high compressive strength of inorganic materials, and strong support for drilling holes, it can realize pressure grouting and sealing holes, but organic materials are used as plugs at the innermost end of drilling holes. It will still happen that the plug is not sent to the predetermined position, and the foaming and expansion will cause the sealing quality to be poor or even waste.

In addition, polymer organic materials such as polyurethane have certain toxicity, which will cause certain harm to the health of workers.

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