Carbon dioxide fracturing anti-reflection device for coalbed methane extraction

Abstract

The invention discloses a carbon dioxide fracturing anti-reflection device for coal bed gas extraction. According to the invention, a detonating cavity is arranged between a detonating assembly and ananti-reflection liquid storage assembly; a low-melting-point molten liquid metal can be injected into the detonation cavity so that detonation of liquid carbon dioxide in the anti-reflection liquid storage assembly can be achieved through energy released by the low-melting-point molten liquid metal, the detonation speed can be greatly increased, instant strong detonation expansion impact force can be achieved, and the anti-reflection effect can be guaranteed. Through the combined use of a first liquid storage pipe, a second liquid storage pipe and a third liquid storage pipe, the quantity ofsections of liquid storage pipes can be selected and used according to the depth of a coalbed, so that the working efficiency is improved. Through the combined use of an energy relief head main body,a support frame, a spring, a sealing gasket and an exhaust pressure relief hole, carbon dioxide can be uniformly diffused into a coalbed, so that the fracturing and anti-reflection effects are better.

Description

technical field [0001] The invention relates to the technical field of coal mine gas extraction, in particular to a coal bed gas extraction device using carbon dioxide cracking to increase permeability. Background technique [0002] In my country's gas mines, quite a few coal seams are low-permeability and difficult-to-drain coal seams, resulting in low gas drainage rate, gas drainage volume and drainage concentration. Therefore, how to change the gas permeability of the coal seam and improve the gas drainage rate of the coal seam has always been a difficult problem in the comprehensive management of gas. Carbon dioxide fracturing and anti-permeability is a new technology for underground coal seam anti-permeability in coal mines. By using liquid carbon dioxide to heat and gasify and expand, high-pressure carbon dioxide gas is released quickly. However, most of the current anti-reflection devices use heaters to heat carbon dioxide on site to make it expand to detonate. The ...

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Problems solved by technology

However, most of the current anti-reflection devices use heaters to heat carbon dioxide on site to make it expand to detonate. The energy released by the detonation is greatly limited

Moreover, the existing structure is difficult to splice the liquid storage pipe according to the depth of the coal seam, so as to achieve the most suitable length, it is difficult to make the carbon dioxide uniformly diffuse into the interior of the coal seam, and it is difficult to treat the liquid carbon dioxide inside the liquid storage pipe at high temperature from the outside , so that the liquid carbon dioxide inside the liquid storage tube can be quickly vaporized, and the detonation anti-permeability can be improved

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