An important upscaling effect in heterogeneous poroelastic Biot media
is the dissipation mechanism due to wave-induced fluid flow caused
by mesoscopic scale heterogeneities. A typical mesoscopic heterogeneity
has a size of tens of centimeters and can be due to local variations
in lithological properties or to patches of immiscible fluids. For
example, a fast compressional wave traveling across a porous rock
saturated with water and patches of gas induces a greater fluid pressure
in the gas patches than in the water saturated parts of the material.
This in turn generates fluid flow and slow Biot waves which diffuse
away from the gas-water interfaces generating significant losses
in the seismic range. In this work an iterative domain-decomposition
finite-element procedure is presented and employed to simulate this
type of upscaling effects in alternating layers of poroelastic rock
saturated with either gas or water. The domain-decomposition procedure
is naturally parallelizable, which is a necessity in this type of
simulations due to the large number of degrees of freedom needed
to accurately represent these attenuation effects. The numerical
simulations were designed to show the effects of the wave-induced
fluid flow on the traveling waves. Our results are the first numerical
evidence of the mesoscopic loss mechanism in the seismic range of
frequencies for this type of porous heterogeneous media.