f SH-Wave velocity and attenuation in poroelastic transverse isotropic media

due to horizontal layering shows very often one axis of symmetry and thus transverse isotropy. It can be described by the Thomsen (1986) parameters є, γ, δ, together with P- and S-wave velocities α, ß, or with a formalism for fluid-filled, aligned cracks, (Schoenberg and Douma, 1988). This kind of anisotropy doesn't exceed 10 to 30 per cent in most cases of interest, whereas the likewise transverse isotropic permeability may exceed in a direction parallel to the fracture planes the premeability normal to fracturing by more than an order of magnitude. Therefore, it defines the main direction of fluid flow during the production process.