Kinematic Variables in Poroelasticity and Interfacial Strain
T.M. Mueller, P.N. Sahay and M. Pervukhina
Event name: 79th EAGE Conference and Exhibition 2017
Session: Rock Physics I - Pore structures and Stress effects
Publication date: 12 June 2017
Info: Extended abstract, PDF ( 1.34Mb )
Price: € 20
Poroelastic constitutive relations play an important role in modelling the static and dynamic behaviour of fluid-saturated rocks. However, the various poroelastic theories use different sets of kinematic variables to describe deformation and their interrelations require further study. We use the volume averaging approach to elaborate on the interrelation between volumetric strain and porosity changes and to highlight the importance of the interfacial strain. In particular, we show that the deviatoric interfacial strain describes the fabric changes of the porous medium in response to an applied stress field and gives rise to an anisotropic stress-strain relation at the macroscale. This notion of poroelastic anisotropy via interfacial motion is entirely different from Biot’s original way of describing poroelastic anisotropy.