Kirchhoff pre-stack depth scalar migration in a simple triclinic velocity model for three-component P, S1, S2 and converted waves
Abstrakt
Migration of multi-component elastic data in anisotropic models is difficult and has not been reasonably addressed. Thus we test three-dimensional ray-based Kirchhoff pre-stack depth scalar migration and calculate migrated sections in a simple anisotropic velocity model.
We generate ray-theory seismograms for separate phases of reflected P, S1, S2 and converted waves. The velocity model is composed of two homogeneous layers and one curved interface.
The anisotropy of the upper layer is triclinic and the bottom layer is isotropic. We apply a scalar imaging separately to each component of the elementary wave in a single-layer velocity model with the same triclinic anisotropy as in the upper layer of the velocity model used to calculate the recorded wave field.
Results of Kirchhoff pre-stack depth scalar migration indicate big differences for individual elementary wave components. We observe very good migrated interface for all three components of reflected PP wave, radial component of PS1 converted wave and transversal component of PS2 converted wave.
For other components and elementary waves, the migrated interface is imaged, only partially, correctly.