Kirchhoff prestack depth migration in 3-D models with velocity gradients: Comparison of triclinic anisotropy with simpler anisotropies
Abstrakt
We use the Kirchhoff prestack depth migration to calculate migrated sections in simple anisotropic velocity models in order to demonstrate the impact of anisotropy and simple inhomogeneity on migrated images. The recorded wave field is generated in velocity models composed of two layers separated by a non-inclined curved interface.
The upper layer has triclinic anisotropy and a velocity gradient. The bottom layer is isotropic and homogeneous.
We apply the Kirchhoff prestack depth migration to both heterogeneous and homogeneous single-layer velocity models with different types of anisotropy: a triclinic anisotropic medium, the transversely isotropic media with a horizontal symmetry axis and a vertical symmetry axis. We show the errors of the migrated interface caused by inaccurate velocity models used for migration.
The study is limited to P-waves.