APPARENT PRECONSOLIDATION STRESS AND SEALING CHARACTERISTICS OF ARGILLACEOUS CAP ROCKS
LIU Junxin1,2,3,YANG Chunhe1,3,LIU Wei1,3,HUO Liang3,MAO Haijun1
(1. State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan,Hubei 430071,China;2. School of Civil Engineering and Architecture,Southwest University of Science and Technology,Mianyang,Sichuan 621010,China;3. State Key Laboratory of Coal Mine Disaster Dynamics and Control,
Chongqing University,Chongqing 400044,China)
Abstract:It has been gradually recognised in oil and gas exploration that it is not adequate to study only the current sealing properties of cap rocks. The geological history and the relationship between the stress state and the brittleness-ductility of the cap rock should also be understood for proper assessment of the sealing properties. A uniaxial strain test was carried out for argillaceous rocks at different diagenesis states from the western Hubei—eastern Chongqing area,using a thick-walled steel drum as a lateral restrainer. The relationship between lateral stress and axial stress was established based on the theory of thick-walled cylinders,and the apparent preconsolidation stress was calculated. Subsequently,the relationships between the apparent preconsolidation stress and the uniaxial compressive strength,the ultrasonic velocity,the porosity,the clay mineral content,and the changes in lateral stress coefficients were investigated. Preliminary assessments of the characteristics of the brittleness to ductility transfer of argillaceous rocks are given with the corresponding onset threshold conditions,as well as the sealing capacity under various geological conditions. This work lays the foundation for subsequent work in establishing the dynamic-static sealing model for argillaceous cap rocks.
高 霞,谢庆宾. 浅析膏盐岩发育与油气成藏的关系[J]. 石油地质与工程,2007,21(1):9-11.(GAO Xia,XIE Qingbin. Brief discussion on the relation between the development of salt and gypsum rock and hydrocarbon accumulation[J]. Petroleum Geology and Engineering,2007,21(1):9-11.(in Chinese))
Your browse does not support frame!