1. Experimental study on displacement of CH4 by liquid CO2 in coal seam.
- Author
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Fei, Jinbiao, Wang, Hu, Wen, Hu, Fan, Shixing, Li, Zhenbao, Liu, Mingyang, and Xu, Yu
- Subjects
COAL ,COAL mining ,FLAME temperature ,GAS bursts ,GAS well drilling - Abstract
Mine gas drainage is an important work in high gas outburst coal mines. How to improve the gas drainage concentration and drainage volume has always been the direction of exploration by coal mine technicians. In this paper, the experiment and field test of displacing CH
4 with liquid CO2 were carried out. In the process of low temperature liquid CO2 phase transformation, a low stress and high permeability pressure relief area is formed in the coal and rock mass, so as to accelerate the free state of primary gas in coal and realize the intensified gas extraction of low-permeability coal seams. The results show that CH4 concentration and displacement efficiency in the displacement flow decrease at a greater rate and then stabilize; the cumulative CH4 displacement volume increases rapidly and stabilizes after reaching the critical time; the average concentration of gas drainage from single hole increases from 27.2% to 53.2%, and the gas drainage purity increases 2.3 times from 0.018 m3 /min to 0.041 m3 /min. The technology is simple to operate, does not produce high temperature and open flame, has the advantages of economy, safety, high efficiency and so on, it can be popularized and applied in gas mines. [ABSTRACT FROM AUTHOR]- Published
- 2024
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