XIAO Z G, ZHANG X P, HAO M, et al.Experimental study on the desorption characteristics of gas-containing coal under flooded environment[J].Journal of Henan Polytechnic University(Natural Science) ,2023,42(6):37-43.

doi:10.16186/j.cnki.1673-9787.2022100019

Received:2022/10/09

Revised:2023/04/27

Published:2023/11/25

Experimental study on the desorption characteristics of gas-containing coal under flooded environment

XIAO Zhiguo1,2,3, ZHANG Xiaopeng4, HAO Mei1, TANG Zhihao1, LIU Yongqiang1

1.College of Safety Science and Engineering，Henan Polytechnic University，Jiaozuo  454000，Henan，China;2.State Key Laboratory Cultivation Base for Gas Geology and Gas Control，Henan Polytechnic University，Jiaozuo  454000，Henan，China;3.Collaborative Innovation Center of Coal Work Safety and Clean High Efficiency Utilization，Henan Polytechnic University，Jiaozuo  454000，Henan，China;4.Baode Coal Mine，CHN Energy Shendong Coal Group Co.，Ltd.，Xinzhou  036600，Shanxi，China

Abstract:During the life cycle of a coal mine，the phenomenon of a coal seam being flooded by water occurs from time to time，and the desorption characteristics of the coal seam gas change greatly in the flooded environment.In order to accurately control coal seam gas，an experimental study on gas desorption characteristics in the flooded environment was carried out.The test results showed that the cumulative gas desorption amount，the initial gas desorption rate and the gas diffusion coefficient were greatly reduced with the increase of the flooded time，and all of them had obvious linear relationship with the flooded time.Low-field Nuclear Magnetic Resonance (NMR) testing additionally revealed an increase in the total amount of water infiltrating coal pores with prolonged flooding.A dynamic mechanism for coal seam gas desorption in flooded environments was proposed through theoretical analysis.When the moisture enters coal pores and fissures，the free gas in coal pores is not only subject to the dynamic action of its own residual gas pressure，but also subject to the resistance of the water in coal pores and fissures.When the power is greater than the resistance，the free gas can break through the shackles of the water film，and when the resistance is greater than the power，the water lock effect is generated.The depth of water intrusion increases with the flooded time，so the difficulty of water being discharged increases，and the water lock effect is enhanced.

Key words:flooded environments;coal seam;gas;desorption characteristics;kinetic mechanism

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