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AK: Akustik

AK 4: Physikalische Seismologie (Sitzungsorganisation: Sergei A. Shapiro, Berlin)

AK 4.2: Vortrag

Montag, 7. März 2005, 11:00–11:15, TU EB222

Numerical considerations of fluid effects on wave propagation: Influence of the tortuosity — •Erik H. Saenger — FU Berlin, Fachrichtung Geophysik, Malteserstrasse 74 - 100, Build. D, 12249 Berlin

The focus of this paper is on effective elastic properties (i.e. velocities) in three different kinds of dry and fluid-saturated porous media. The synthetic results are compared with the predictions of the Gassmann equation and the tortuosity-dependent high-frequency limit of the Biot velocity relations. Using a dynamic finite-difference approach we observe for Fontainebleau sandstone the same effective elastic properties as with a static finite-element approach. We show that so-called open-cell Gaussian random field models are similar in mechanical properties to Fontainebleau sandstone. For all synthetic models considered in this study the high-frequency limit of the Biot velocity relations is very close to the predictions of the Gassmann equ ation. However, using synthetic rock-models saturated with an imaginary fluid of high density we can approximately estimate the corresponding tortuosity parameter.