Attenuation at Patchy Saturation – A Model

E-23 ATTENUATION AT PATCHY SATURATION – A MODEL J. DVORKIN 1 J. WALLS 2 T. TANER 2 N. DERZHI 2 and G. MAVKO 1 1 1 Stanford University and Rock Solid Images 2600 S.Gessner Suite 650 Houston TX 77063 USA Summary. Wave-induced variations of pore pressure in a partially-saturated reservoir result in oscillatory liquid flow. The viscous losses during this flow are responsible for wave attenuation. The same viscous effects determine the changes in the dynamic bulk modulus of the system versus frequency. These changes are necessarily linked to attenuation via the causality condition. We analytically quantify the frequency dependence