时间: 2023-11-10 | 次数: |
肖知国, 张晓鹏, 郝梅,等.水淹环境下煤层瓦斯解吸特性的实验研究[J].河南理工大学学报(自然科学版),2023,42(6):37-43.
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.
水淹环境下煤层瓦斯解吸特性的实验研究
肖知国1,2,3, 张晓鹏4, 郝梅1, 唐志昊1, 刘永强1
1.河南理工大学 安全科学与工程学院,河南 焦作 454000;2.河南理工大学 河南省瓦斯地质与瓦斯治理重点实验室-省部共建国家重点实验室培育基地,河南 焦作 454000;3.河南理工大学 煤炭安全生产与清洁高效利用省部共建协同创新中心,河南 焦作 454000;4.国能神东煤炭 保德煤矿,山西 忻州 036600
摘要:在煤矿生命周期内,水淹煤层现象时有发生,水淹环境下煤层瓦斯的解吸特性将发生较大变化,为了精准防治煤层瓦斯,开展了水淹环境下瓦斯解吸特性的实验研究,结果表明:随着水淹时长增加,累计瓦斯解吸量、初始瓦斯解吸速度和气体扩散系数均出现大幅降低,三者均与水淹时长线性关系明显;低场核磁共振测试表明,随着水淹时长增加,进入煤体孔隙中的水分增加。经理论分析,提出水淹环境下煤层瓦斯解吸的动力机制,当水分进入煤的孔-裂隙中时瓦斯既受到自身残余压力的动力作用,又受到孔-裂隙中水的阻力作用,当动力大于阻力时,瓦斯冲破水膜束缚;当阻力大于动力时,产生水锁效应;随着水淹时长增加,水分侵入煤体的深度增加,水分被排出的难度增加,从而水锁效应增强。
关键词:水淹环境;煤层;瓦斯;解吸特性;动力机制
doi:10.16186/j.cnki.1673-9787.2022100019
基金项目:国家自然科学基金资助项目(52274186,51204066);河南理工大学博士基金资助项目(B2012-082)
收稿日期:2022/10/09
修回日期:2023/04/27
出版日期: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