The effective pressure law for permeability of clay-rich sandstones  

作　　者：Zhao Jinzhou Xiao Wenlian Li Min Xiang Zuping Li Lijun Wang Jun 

机构地区：[1]State Key of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu, Sichuan 610500, China [2]Exploration ＆ Development Research Institute, Sinopec Southwest Branch, Chengdu, Sichuan 610081, China

出　　处：《Petroleum Science》2011年第2期194-199,共6页石油科学（英文版）

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)

摘　　要：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）.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）.

关 键 词：PERMEABILITY effective pressure coefficient slide method CLAY SANDSTONES 

分 类 号：P588.22[天文地球—岩石学] TQ022.8[天文地球—地质学]