Cross-equalization processing removes unwanted differences between the imaged data sets.
Such differences may be caused by uncorrelated noise or geomechanical changes.
The post-imaging procedure can be divided into two steps.
First, because direct velocity analysis with the recorded data is difficult, we assume that a baseline velocity model built from conventional seismic data will be used to image all data sets.
This leads to image misalignment due to reservoir compaction and velocity changes between surveys.
To align the monitor and baseline images, a cyclic 1D correlation method is used to estimate vertical and horizontal displacement components (Hale, 2009).
The aligned images are then matched using an optimized matching procedure.
Match filters estimated in non-reservoir regions are applied to the monitor data on a trace-by-trace basis.
These cross-equalization steps are discussed in detail by Ayeni (2010).