HR: 1330h
AN: H32A-0534    [PDF]
TI: Wave Propagation through Porous Media Containing two Immiscible Fluids
AU: * Lo, W
EM: lowc@uclink.berkeley.edu
AF: Department of Civil and Environmental Engineering, University of California, Berkeley, CA 94720-1710 United States
AU: * Lo, W
EM: lowc@uclink.berkeley.edu
AF: Department of Geophysics and Geomechanics, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 United States
AU: Sposito, G
EM: gsposito@nature.berkeley.edu
AF: Department of Civil and Environmental Engineering, University of California, Berkeley, CA 94720-1710 United States
AU: Sposito, G
EM: gsposito@nature.berkeley.edu
AF: Department of Geophysics and Geomechanics, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 United States
AU: Majer, E L
EM: elmajer@lbl.gov
AF: Department of Geophysics and Geomechanics, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 United States
AB: Over the last three decades, an enormous amount of research has been dedicated to studying the physical mechanisms involved with elastic wave propagation and attenuation in fully saturated porous media. On the other hand, the modeling of elastic wave propagation and attenuation through unsaturated porous media has received little attention due to the complexity of developing an adequate theoretical representation. The current literature is lacking a mathematical model which simultaneously considers effects of inertial coupling and changes in capillary pressure in an Eulerian framework. The development of this kind of generalized theory can be undertaken in a systematic manner starting from momentum balance equations we have derived for immiscible two-phase fluid flows in deformable porous media. Based on our new model, a dispersion equation for the dilatational waves in unsaturated porous media was derived to describe how wave frequency depends on wavenumber. For a given wave frequency, we show analytically that there are three dilatational body waves existing in partially-saturated porous media. To gain insight into the fluid-dependent nature of three dilatational waves, a numerical simulation was performed to investigate the phase velocity and attenuation coefficient of three different modes of dilatational waves as functions of wave frequency and water saturation in Columbia fine sandy loam containing either water and air or water and oil.
DE: 0902 Computational methods, seismic
DE: 1875 Unsaturated zone
DE: 3200 MATHEMATICAL GEOPHYSICS (New field)
SC: Hydrology [H]
MN: 2003 Fall Meeting