Post-stack velocity analysis by separation and imaging of seismic diffractions

Published as Geophysics, 72, U89-U94, (2007)

Post-stack velocity analysis by separation and imaging of seismic diffractions

Sergey Fomel, Evgeny Landa, and M. Turhan Taner

Bureau of Economic Geology
John A. and Katherine G. Jackson School of Geosciences
The University of Texas at Austin
University Station, Box X
Austin, TX 78713-8972
USA
OPERA
Batiment IFR
rue Jules Ferry
64000 Pau
France
Rock Solid Images
2600 South Gessner, Suite 650
Houston, TX 77063
USA

Abstract:

Small geological features manifest themselves in seismic data in the form of diffracted waves, which are fundamentally different from seismic reflections. Using two field data examples and one synthetic example, we demonstrate the possibility of separating seismic diffractions in the data and imaging them with optimally chosen migration velocities. Our criterion for separating reflection and diffraction events is the smoothness and continuity of local event slopes that correspond to reflection events. For optimal focusing, we develop the local varimax measure. The objectives of this work are velocity analysis implemented in the post-stack domain and high-resolution imaging of small-scale heterogeneities. Our examples demonstrate the effectiveness of the proposed method for high-resolution imaging of such geological features as faults, channels, and salt boundaries.

Post-stack velocity analysis by separation and imaging of seismic diffractions