In-situ numerical testing of CO2 sequestration in coal: dual poroelastic effects
When CO2 is injected, complex interactions of stress and chemistry have a strong influence on the properties of the coal. This influence is regulated by the applied mechanical boundary conditions. In this study, we developed two new porosity models for coal matrixes and fractures, respectively. Both models are valid under conditions of variable stress. A cubic relation between porosity and permeability is then introduced to relate coal storage capability (changing porosity) to coal transport characteristics (changing permeability) also under variable stress conditions. We implement these two relations into a dual porelastic model to represent the coupled multiphysics of coal-gas interactions. This relaxes the prior assumption that total stresses remain constant and allows exploration of the full range of mechanical boundary conditions from invariant stress to restrained displacement. Results of numerical tests under variable mechanical boundary conditions demonstrate the controlling effects of boundary conditions on the evolution of coal porosities and permeabilities, the competition between effective stress effect and matrix swelling effects, and the dynamics of interactions between coal matrix system and coal fracture system.
dual poroelastic adsorption effective stress porosity model
Y. Wu J.S.Liu Z.W.Chen D. Elsworth L. D. Connell
School of Science, China University of Mining & Technology, Xuzhou, 221008, Jiangsu, China School of School of Mechanical Engineering, The University of Western Australia, Perth, 6009, Australia Department of Energy and Mineral Engineering, Penn State University CSIRO Petroleum Resource, Melbourne, 3169, Australia
国际会议
徐州
英文
695-703
2009-09-24（万方平台首次上网日期，不代表论文的发表时间）