TY - JOUR
T1 - Asynchronous difference in dynamic characteristics of adsorption swelling and mechanical compression of coal
T2 - Modeling and experiments
AU - Zhao, Wei
AU - Wang, Kai
AU - Liu, Shimin
AU - Ju, Yang
AU - Zhou, Hongwei
AU - Fan, Long
AU - Yang, Yun
AU - Cheng, Yuanping
AU - Zhang, Xiaolei
N1 - Publisher Copyright:
© 2020 Elsevier Ltd
PY - 2020/11
Y1 - 2020/11
N2 - Sorption-induced strain of coal is vital to the prediction of coal bed methane production and stimulation. Previous studies have addressed the relationship between strain and equilibrium pressure and the relationship between strain change and permeability evolution. However, the strain variations with respect to time and the comparison between the asynchronous difference of dynamic characteristics of adsorption swelling and mechanical compression were rarely explored. In this study, we investigated the anisotropy characteristics of strain change over time as well as the influence of the gas species, gas pressure, and pore structure on the dynamic strain variations by using the low temperature liquid nitrogen adsorption method and a self-designed coal strain measurement apparatus. Our results show that gas diffusion rate has a strong influence on sorption-induced strain of coal. Both mechanical compression and sorption-induced strain exhibited an asynchronous effect with respect to saturating time. We then propose a time-depended volumetric deformation model for coal to analyze the mechanism of the asynchronous effect during sorption. This study sheds light on the dynamic process of coal bed methane production and reveals restrictions of current permeability models.
AB - Sorption-induced strain of coal is vital to the prediction of coal bed methane production and stimulation. Previous studies have addressed the relationship between strain and equilibrium pressure and the relationship between strain change and permeability evolution. However, the strain variations with respect to time and the comparison between the asynchronous difference of dynamic characteristics of adsorption swelling and mechanical compression were rarely explored. In this study, we investigated the anisotropy characteristics of strain change over time as well as the influence of the gas species, gas pressure, and pore structure on the dynamic strain variations by using the low temperature liquid nitrogen adsorption method and a self-designed coal strain measurement apparatus. Our results show that gas diffusion rate has a strong influence on sorption-induced strain of coal. Both mechanical compression and sorption-induced strain exhibited an asynchronous effect with respect to saturating time. We then propose a time-depended volumetric deformation model for coal to analyze the mechanism of the asynchronous effect during sorption. This study sheds light on the dynamic process of coal bed methane production and reveals restrictions of current permeability models.
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U2 - 10.1016/j.ijrmms.2020.104498
DO - 10.1016/j.ijrmms.2020.104498
M3 - Article
AN - SCOPUS:85091982766
SN - 1365-1609
VL - 135
JO - International Journal of Rock Mechanics and Mining Sciences
JF - International Journal of Rock Mechanics and Mining Sciences
M1 - 104498
ER -