Abstract
Stacking is a common technique to improve the signal-to-noise ratio
(S/N) and the imaging quality of seismic data. Conventional stacking
that averages equally a collection of normal moveout corrected or
migrated shot gathers with a common reflection point is not always
satisfactory. Instead, we propose a novel time-dependent weighted
average stacking method that utilizes local correlation between each
individual trace and a chosen reference trace as a measure of weight
and a new weight normalization scheme that ensures meaningful amplitudes
of the output. Three different reference traces have been proposed.
These are based on conventional stacking, S/N estimation, and Kalman
filtering. The outputs of the enhanced stacking methods, as well
as their reference traces, were compared on both synthetic data and
real marine migrated subsalt data. We conclude that both S/N estimation
and Kalman reference stacking methods as well as the output of the
enhanced stacking method yield consistently better results than conventional
stacking. They exhibit cleaner and better defined reflection events
and a larger number of reflections. We found that the Kalman reference
method produces the best overall seismic image contrast and reveals
many more reflected events, but at the cost of a higher noise level
and a longer processing time. Thus, enhanced stacking using S/N estimation
as reference method is a possible alternative that has the advantages
of running faster, but also emphasizes some reflected events under
the subsalt structure.
Users
Please
log in to take part in the discussion (add own reviews or comments).