TY - JOUR
TI - Experimental study on the mechanism of water affecting the permeability characteristics of sandstone
AU - Gao Heng
AU - Zhang Zhi-Long
AU - Lu Jun
AU - Zhang Ze-Tian
JN - Thermal Science
PY - 2023
VL - 27
IS - 1
SP - 581
EP - 589
PT - Article
AB - The permeability characteristics of sandstone are of great importance for  un-conventional natural gas extraction, CO2 geological storage, coal mine  gas safety, etc. Under the influence of tectonic stress and mining-induced  stress, the evolution of permeability becomes exceptionally complex. A  number of studies have focused on the evolution of permeability under  different stress paths, ignoring the effect of water on sandstone  permeability. The permeability evolution of sandstone in dry and saturated  states under high and low surrounding pressures was investigated by triaxial  tests. The results show that the triaxial compressive strength of the  specimen significantly decreases under saturated conditions. Specifically,  the triaxial compressive strength decreases by 27.12% and 10.52% under low  and high confining pressure, respectively. Compared to the dry specimen, the  permeability of the saturated specimen significantly decreases at all  stages of loading, the initial permeability of the saturated specimen is  decreased by 92.09% and 56.25% at low and high confining pressure,  respectively. The S&D model was matched with the test data, an excellent  goodness of fit was obtained in the elastic and plastic phase, and the  mechanism of water affecting sandstone permeability was analyzed.