Coal mine gas pre-draining borehole sealing method adopting aerated capsule as temporary hole bottom

Abstract

The invention relates to a method for sealing a coal-mine gas pre-drainage borehole by adopting an inflatable capsule as a temporary borehole bottom. The method is mainly to solve technical problems of the prior g method for sealing the borehole, such as high sealing cost, low efficiency and inconvenient operation. The invention adopts the technical proposal that: the method for sealing the coal-mine gas pre-drainage borehole by adopting the inflatable capsule as the temporary borehole bottom comprises the following steps of: a. lifting a drilling tool and placing an borehole orifice pipe into a borehole, after a gas pre-drainage drill drills to a terminal drilling depth; b. sending the inflatable capsule into the borehole and inflating the inflatable capsule to form the temporary borehole bottom; c. filling cement mortar from the borehole orifice pipe, until the cement mortar is filled with the whole annular space; d. deflating the inflatable capsule and restoring the inflatable capsule to the original state, after the cement mortar is solidified, taking out the inflatable capsule from the borehole orifice pipe to complete sealing. The method is particularly applicable to sealing operations for the gas pre-drainage borehole which uses rigid plastic or other materials to make into the borehole orifice pipe and the gas pre-drainage borehole with poor shaping in a soft coal seam.

Description

technical field [0001] The invention relates to a hole sealing method for coal mine gas pre-extraction drilling using an inflatable capsule as a temporary hole bottom, which belongs to a method especially suitable for gas pre-extraction drilling and soft coal seams using hard plastic and other materials as orifice pipes Hole sealing method for poorly formed gas pre-drainage boreholes. It is also suitable for the sealing operation of gas pre-drainage drilling holes at horizontal and arbitrary inclination angles and the sealing operation of water injection drilling holes in coal seams. Background technique [0002] Coal mine gas is one of the main disasters of coal mine safety production, and it is also a kind of clean energy. At present, mines threatened by gas disasters in my country (especially high gas mines) have generally adopted the method of pre-extracting gas to prevent and control gas disasters, and the extracted gas is used. In addition, coal mines also use the me...

AI Technical Summary

Problems solved by technology

[0006] For the former sealing process, the waiting time of the cement mortar is in the middle of the drilling construction, so the drilling rig must either stop at the drilling site for at least one small shift, or open a new drilling site and replace the new / old drilling machine. Reciprocating drilling rigs between sites will result in waste of man-hours; and during secondary drilling, drilling tools may cause wear to the orifice pipe (especially when using low-cost plastic pipes with poor wear resistance), which may cause damage to hard rocks. The vibration may also cause the cement mortar that has solidified to lose its seal.

For the latter sealing process, although it avoids the waste of man-hours caused by rig stoppage and relocation, and avoids the disadvantages of wear and disturbance to the orifice pipe and sealing filling material by secondary drilling; Far away from the bottom of the natural hole, it is impossible to use the barrier of the bottom of the natural hole to form the back flow of grouting, so it brings difficulties to the implementation of the cementing mortar process

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