Fracturing method of automatic energy storage high-pressure liquid injection co2 phase change pulse coal rock mass

Abstract

The invention discloses an automatic energy storing high-pressure liquid injecting CO2 phase change pulse coal and rock body cracking method. Liquid state CO2 enters a high-pressure liquid injecting cylinder and a phase change chamber in the mode that the liquid state CO2 is injected into a high-pressure liquid storing temperature control tank, the liquid state CO2 in the phase change chamber is heated, the phase change pressure is increased, and gaseous CO2 enters the energy storing chamber to be subjected to automatic energy storing and a coal rock cracking chamber to be cracked; and when the pressure of the CO2 gas in the phase change chamber is decreased, the high-pressure CO2 gas enters the high-pressure liquid injecting cylinder to push a piston to expel the remaining CO2 gas, and enters the coal rock cracking chamber to be subjected to second-time cracking, the circulation of liquid injection, oil bath heating, phase change, energy storing and cracking is repeated, and continuous pulse high pressure flow jetting cracking is realized. According to the method, continuous pulse high pressure flow jetting cracking is realized, the time of cracking action is prolonged, the range of cracking action is expanded, the cracking effect is improved, and the method is suitable for quick and efficient cracking of solid materials such as coal, rock, concrete, soil and congelation.

Description

technical field [0001] The present invention relates to a CO 2 A phase-change solid cracking method, specifically a method that utilizes liquid CO 2 A method for fracturing coal and rock mass as a phase-change pressurized medium. Background technique [0002] With the rapid development of the national economy, the scale and quantity of engineering construction continue to expand, and the cracking of solid materials is involved in many engineering processes, such as in-situ directional cracking of rock mining in quarries, demolition of structures or buildings , Tunnel excavation, mining, broken roof of mining face or roadway, loosening and depressurization of coal and rock mass in high stress area, pipe wall cleaning, separation of frozen matter in alpine area, especially fracturing and permeability enhancement of low permeability oil and gas reservoirs, etc. , the cracking method will directly affect the progress, effect and safety of the project. At present, the methods ...

AI Technical Summary

Problems solved by technology

[0004] One is that the peak pressure duration of this method is short and continuous action cannot be achieved

The volume of the carbon dioxide burst tube is generally about 1.2L, and the liquid CO2 that can be accommodated 2 Very limited, the continuous injection time in one fracturing process is very short, the high pressure maintenance time is even shorter, only tens of milliseconds, the fracturing range is small, the effect is poor, and the fracturing efficiency is low

[0005] Second, this method is susceptible to interference during on-site construction. For example, the detonation line is easily interfered by the water in the coal seam, which leads to the failure of normal conduction detonation.

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