Z-99 Attenuating the effects of pre-stack depth migration for AVA analysis.

Whatever the pre-stack depth migration we may use, both migrated sections (common offset or common angle) and associated common image gathers sections are commonly obtained in 3D offset or angle domain. These gathers can be used for velocity model updating but also for amplitude versus angle (AVA) analysis (Beydoun et al., 1993), as presented here. However, several authors advocated the need for an optimal seismic processing workflow prior to the inversion, mainly in order to correct residual move-out and wavelet variation with offset which can severely bias the inversion results. Here, we present the advantages of our specific post-migration for an optimal stability of the AVA inversion and illustrate it in the specific case of thin beds when stretching of the far-offset wavelet occurs