Impact of TTI Anisotropy on Elastic and Acoustic Reverse Time Migration

In this study, we use synthetic seismic data to demonstrate the impact of proper anisotropic parameterization as well as the choice of elastic migration algorithm on the output image. We synthesize an elastic dataset using a 2D TTI elastic model based on the SEAM 3D model. Then we migrate this dataset using isotropic acoustic RTM, VTI acoustic RTM, TTI acoustic RTM, and TTI elastic RTM algorithms, respectively. Image quality improves progressively as we use more realistic models as well as more accurate elastic wave-propagation engine. Upgrading from TTI acoustic RTM to TTI elastic RTM results in better delineation of the salt boundary and better sediment termination against faults and salt. These differences result from the fundamental limitations of migrating elastic data using acoustic RTM and result from the proper positioning of converted waves.