A freeze-drilling carbon dioxide phase change fracturing auxiliary tunneling method and its device

Abstract

Disclosed is a directional CO2 cracker. Two rows of directional energy discharge openings (1, 1') are distributed at both sides of an energy discharge head thereof in the axial direction, and the phase angle of the two rows of directional energy discharge openings (1, 1') is less than 180 degrees; in a freezing shaft-sinking process, a plurality of directional CO2 crackers are arranged on the outer periphery of a working face, and a plurality of common CO2 crackers are arranged on the inner periphery of a wellbore; the directional energy discharge openings (1, 1') at the both sides of the energy discharge head of each of the directional CO2 crackers respectively face the directional CO2 crackers adjacent thereto; the directional CO2 crackers in an outer-ring borehole (3) are detonated first, and then, the common CO2 crackers in an inner-ring borehole (4) are detonated; the directional CO2 crackers in the outer-ring borehole (3) direct energy to be released along the directional energy discharge openings (1, 1'), and blasting cannot disturb a wall structure outside the wellbore; after the outer-ring borehole (3) is blasted, a communicating weak surface is formed among the outer-ring boreholes (3), and the entire outer-ring boreholes (3) form a protective ring; and when the inner-ring borehole (4) is blasted, the protective ring formed by the outer-ring boreholes (3) cuts off the propagation of blasting energy to the wellbore wall, and the disturbance thereof to the wellbore wall structure is reduced.

Description

Technical field [0001] The invention relates to the field of freezing shaft sinking construction in coal mining, and in particular to a method and a device for auxiliary driving of freezing shaft sinking with carbon dioxide phase change fracturing. Background technique [0002] The vertical shaft generally needs to pass through two parts of topsoil and bedrock. Its construction technology has its own characteristics due to different surrounding rock conditions. The selection of topsoil construction scheme mainly considers the safety of the project, while the construction of bedrock mainly considers the construction schedule. When the vertical shaft passes through the topsoil, the topsoil is soft, has poor stability, often contains water, and directly bears the load of the wellhead structure, so the topsoil construction is more complicated and often becomes the key project of the vertical shaft construction. It is of great significance to correctly choose the topsoil construction ...

AI Technical Summary

Problems solved by technology

[0004] In order to overcome the shortcomings of the above-mentioned pneumatic pick or drilling blasting method in the freezing method of drilling and the traditional CO 2 The problem of the inconvenience of phase change generators in shaft excavation construction, the present invention provides a directional CO 2 cracker, with conventional CO 2 Compared with the cracker, two rows of directional energy discharge ports are distributed along the axis direction on both sides of the energy discharge head, and the phase angle of the two rows of directional energy discharge ports is

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