On the influence of the interface Fresnel zone for estimating media parameters from seismic amplitude-versus-angle curves

Nathalie Favretto-Cristini (1) , Paul Cristini (1) , Eric de Bazelaire (1)

1 MIGP - Laboratoire de Modélisation et d'Imagerie en Géosciences de Pau

The band-limited property and the low-frequency content of the seismic data are rarely taken into account in wave reflection modeling. In this work we point out the consequences of ignoring such signal characteristics in both forward and inverse modeling of seismic wave reflection. The variation in the reflected P-wave amplitude as a function of the incidence angle, also known as AVA curve, obtained with the classical plane-wave (PW) theory, is compared with the exact solution provided by the 3D code OASES, and with our approximation which accounts for the spatial region which physically contribute to the wave reflection process, i.e. the Interface Fresnel zone. Our approximation provides much better data predictions than the PW theory, widely used in AVA studies in seismic exploration. Moreover, assuming that the AVA curves corresponding to real data may be well described by the PW theory leads to inaccurate estimations of the media properties. Our approximation may be therefore an attractive alternative to classical methods to extract information relative to bottom parameters from AVA signals.

Domaines: Géophysique [physics.geo-ph]; Géophysique [physics.geo-ph]

Nathalie Favretto-Cristini, Paul Cristini, Eric de Bazelaire. On the influence of the interface Fresnel zone for estimating media parameters from seismic amplitude-versus-angle curves. 2007. ⟨hal-00172411⟩