CO2和He在阳泉煤CH4饱和基质煤柱中的渗流特性

利用自行设计的自约束渗透装置,采用热导检测器在线跟踪穿透实验过程中CO2或He的渗透信号,在40℃条件下,对比研究了CO2和He在阳泉煤CH4饱和基质煤柱(φ6×13mm)中的渗透行为,讨论了煤对气体的吸附或吸取作用及孔隙气压对渗透率的影响.研究表明,有别于煤对He的作用,在CO2和CH4交替渗透时,不同的CH4吹扫时...

Permeability of CO2 and He in Yangquan coal matrix-plug saturated by CH4

The CO₂ permeability of Yangquan coal matrix-plug (φ 6×13mm) saturated by CH₄ was studied by carrying out CO₂ breakthrough tests at 40℃. The similar tests were performed with inert gas He for comparison. The breakthrough tests were performed in a self-confining flow cell equipped with an online thermal conductivity detector for continually monitoring the signal of CO₂ or He. The imbibition of gas by coal and the influence of the pore gas pressure were investigated. It shows that unlike He there is significant residual CO₂ left in the coal matrix even after CO₂ was flushed by CH₄ for 36h. It reveals that coal has stronger imbibition ability for CO₂, which leads to the difference in its breakthrough time for different CH₄ flushing time. No notable residual He is found during the breakthrough tests. He permeability is significantly higher than that of CO₂. The obtained permeability coefficients of the coal plug with CO₂ or He at the steady state are closely the same for the repeat tests. It implies that no significant structure change involved during the tests. The permeability coefficients varied with the pore gas pressure due to the existence of the influences of the pore wall, the swelling of coal and the adsorption boundary layer.