In order to implement and test Stolt residual migration for converted waves, I use a 2D line from a 3D cube of the OBC data set of the Alba oil field. The 2D line is extracted from the 3D portion after geometry regularization Rosales and Biondi (2002).
The velocity models were provided by Chevron. I start
with these velocity models. I first handle the
PP section, perform Stolt residual migration
on this section only and update the velocity model
with a selection of combined values of
. After the
P velocity model is updated, I perform the
PS migration and residual migration; however,
I do not scan over
values. I scan only over
and
values.
The velocities vary both horizontally
and vertically. Therefore, there will not be a single set of parameters
to correct the entire section. The
value will be
choosen
at Alba's depth at the center of the section.