A dynamic sealing method of solid powder-grouting under pressure

Abstract

A method for dynamic sealing of solid powder under pressure grouting, comprising a extraction pipe, a grouting pipe, a grouting pipe, an auxiliary hole, an annular powder groove, a powder injection pipe, a pressure gauge, a powder injection machine, a front baffle, The rear baffle plate and plug are constructed with an annular powder groove through hydraulic slits inside the borehole, and symmetrical auxiliary holes are constructed in the vertical direction of the borehole. The annular powder groove and its front gap are filled with powder material into the auxiliary hole through the powder injection system. The injected solid powder can form a barrier wall to block the external air on the one hand, and can fill the coal around the hole under the action of negative pressure on the other hand. The hole can be sealed by dynamic powder injection according to the reading of the pressure gauge on the powder injection pipe, so as to achieve the purpose of long-term effective sealing of the hole.

Description

technical field [0001] The invention relates to the technical field of coal mine gas drainage, in particular to a drilling hole sealing method for coal seam gas drainage and a hole sealing structure thereof. Background technique [0002] my country is the main coal-producing country in the world, and it is also one of the most serious coal and gas outburst countries. The structure of my country's coal reservoirs is complex, and it is "three lows and one high" (coal seam pressure is low, coal seam permeability is low, and the proportion of long intentional cracks formed under enhanced measures such as water fracturing is low; coal seams generally have Higher adsorption force) physical characteristics. At present, gas drainage is the most effective measure to prevent and control gas disasters. The primary task of gas drainage is to construct and drill holes, and the first condition is to seal the holes. At present, there is a problem of lax sealing of holes in gas drainage, w...

AI Technical Summary

Problems solved by technology

At present, there is a problem of lax sealing of holes in gas drainage, resulting in serious gas leakage during the extraction process, rapid decay of gas concentration, difficulty in extraction, and low efficiency

[0003] At present, the drilling and sealing technologies commonly used in my country's coal mine gas drainage include: cement mortar sealing, polyurethane sealing, hole sealing, etc. Although these technologies are widely used, there are some defects, such as cement mortar sealing. There will be a gap between the back and the drilled wall; the polyurethane sealing operation is cumbersome, and the technical requirements for the sealing personnel are high, and it is easy to cause waste of materials and pollute the environment; the sealing cost of the hole sealing device is high and the sealing depth limited

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