Shale cracking device using carbon dioxide in different phases and experiment method

Abstract

The invention relates to a shale cracking device using carbon dioxide in different phases and an experiment method, and belongs to the technical field of shale gas exploitation. The device comprises aconstant-temperature oil bath, a conventional three-axis loading system, an acoustic emission monitoring system, a CO2 fracturing system, a control system, a deformation testing system, and a gas flow meter. The constant-temperature oil bath is used for controlling experiment temperature; the conventional three-axis loading system is used for loading different axial pressures and confining pressures on shale test pieces; the acoustic emission monitoring system is used for monitoring the acoustic emission characteristic, the three-dimensional damage positioning, and the critical crack initiation pressure of shale during the whole process of shale cracking using carbon dioxide in different phases; the CO2 fracturing system is used for injecting CO2 in different phases into the shale test pieces; and the control system is used for controlling the axial pressure and the confining pressure of a three-axis pressure chamber. According to the shale cracking device using carbon dioxide in different phases and the experiment method, the gaseous state, the liquid state and the supercritical CO2 shale cracking mechanism can be physically simulated by adjusting the temperature and the CO2 pressure; the permeability before and after shale cracking can be detected; and advanced experimental conditions are provided for efficient development of shale gas with CO2.

Description

technical field [0001] The invention belongs to the technical field of shale gas exploitation, and relates to a shale cracking device and an experimental method of carbon dioxide in different phases. Background technique [0002] Organic-rich shale is widely distributed in China. Marine shale is developed in South China, North China and Xinjiang Tarim Basin, and continental shale is developed in North China, Junggar Basin, Turpan-Hami Basin, Ordos Basin, Bohai Bay Basin and Songliao Basin. , the recoverable resources of shale gas are about 25 trillion m 3 , exceeding conventional natural gas resources. At present, large-scale commercial development of shale gas is underway, and shale gas demonstration areas such as Fuling, Changning, Weiyuan, Zhaotong, and Yan'an have been established, with an annual production capacity of 10 billion m 3 , in 2017 the shale gas production reached 6.5 billion m 3 , the total production of shale gas is planned to be 30 billion m in 2020 3 ...

AI Technical Summary

Problems solved by technology

[0005] At present, the research on the mechanism of carbon dioxide fracturing shale at home and abroad is not deep enough, and the experimental devices are rarely developed. It is urgent to independently develop corresponding experimental devices to carry out research in this area.

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