Migration velocity analysis in factorized VTI media

In recent times, seismic imaging efforts around the
world have focused on increasingly complex earth
models that are not only heterogeneous, but
anisotropic as well. Focusing my investigation on
the simplest realistic heterogeneous anisotropic
model --- factorized VTI (transversely isotropic
with a vertical symmetry axis) medium with constant
vertical and lateral gradients in vertical velocity,
I develop insights into how anisotropy and
heterogeneity are coupled, and determine what
parameters can be estimated uniquely from surface
seismic data. I then outline a robust parameter
estimation algorithm that is suitable for building a
spatially varying anisotropic velocity field for
depth imaging. Application of my algorithm to two
field lines from West Africa confirms the presence
of anisotropy and lateral heterogeneity and results
in better images than those previously obtained. The
analysis should help towards increasing our
understanding of seismic imaging and tomography, and
should be useful to Geoscientists studying seismic
images, or anyone else interested in wave
propagation in the earth.

Autorentext

As a senior geophysicist with Ion Geophysical, I have been doing seismic depth imaging projects from different regions of the world for several years. I have a PhD from the Colorado School of Mines, an MS from the University of Oklahoma and an Intg. MSc from the Indian Institute of Technology, Kharagpur, India, all in Geophysics.

Klappentext

In recent times, seismic imaging efforts around the world have focused on increasingly complex earth models that are not only heterogeneous, but anisotropic as well. Focusing my investigation on the simplest realistic heterogeneous anisotropic model --- factorized VTI (transversely isotropic with a vertical symmetry axis) medium with constant vertical and lateral gradients in vertical velocity, I develop insights into how anisotropy and heterogeneity are coupled, and determine what parameters can be estimated uniquely from surface seismic data. I then outline a robust parameter estimation algorithm that is suitable for building a spatially varying anisotropic velocity field for depth imaging. Application of my algorithm to two field lines from West Africa confirms the presence of anisotropy and lateral heterogeneity and results in better images than those previously obtained. The analysis should help towards increasing our understanding of seismic imaging and tomography, and should be useful to Geoscientists studying seismic images, or anyone else interested in wave propagation in the earth.