To study the relative sensitivity of permeability to pore pressure Pp and confining pressure Pc for clay-rich rocks, permeability measurements were performed on samples of four clay-rich sandstones. A new method （her...To study the relative sensitivity of permeability to pore pressure Pp and confining pressure Pc for clay-rich rocks, permeability measurements were performed on samples of four clay-rich sandstones. A new method （hereafter denoted the ＂slide method＂） was developed and used for analyzing the permeability data obtained. The effective pressure coefficients for permeability nk were calculated. The values of nk were found to be greater than 1.0 and insensitive to changes in pressure. These results confirmed observations previously made on clay-rich rocks. Also, the coefficients nk obtained had different characteristics for different samples because of differences in the types of clay they contained. The effective pressure law （σeff=Pc-nkPp） determined using the slide method gave better results about k（oefr） than classic Terzaghi＇s law （σeff=Pc-nkPp）.展开更多
基金supported by a grant from the National Natural Science Foundation of China(Grant No.50774064)the Open Fund PLN0802 of the State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation(Southwest Petroleum University)
文摘To study the relative sensitivity of permeability to pore pressure Pp and confining pressure Pc for clay-rich rocks, permeability measurements were performed on samples of four clay-rich sandstones. A new method （hereafter denoted the ＂slide method＂） was developed and used for analyzing the permeability data obtained. The effective pressure coefficients for permeability nk were calculated. The values of nk were found to be greater than 1.0 and insensitive to changes in pressure. These results confirmed observations previously made on clay-rich rocks. Also, the coefficients nk obtained had different characteristics for different samples because of differences in the types of clay they contained. The effective pressure law （σeff=Pc-nkPp） determined using the slide method gave better results about k（oefr） than classic Terzaghi＇s law （σeff=Pc-nkPp）.
