Abstract for paper submitted to Geophysics, 1999.
Cross-equalization processing for time-lapse seismic reservoir
monitoring data: a case study from the Gulf of Mexico
by
James E. Rickett
Geophysics Department, Stanford University, CA 94305
and
David E. Lumley
4th Wave Imaging Corp.,
850 Glenneyre Street, Laguna Beach, CA 92651
formerly of Chevron Petroleum Technology Co., La Habra, CA
ABSTRACT
Non-repeatable noise, caused by differences in vintages of seismic
acquisition and processing, can often make comparison and
interpretation of time-lapse 3D seismic data sets for reservoir
monitoring misleading or futile. In this Gulf of Mexico case study the
major causes of non-repeatable noise in the data sets are due to
differences in survey acquisition geometry and binning, temporal and
spatial amplitude gain, wavelet bandwidth and phase, differential
static time shifts, and dynamic mispositioning of imaged reflection
events. We suppress these acquisition and processing differences by
developing and applying a cross-equalization data processing flow for
time-lapse seismic data. The cross-equalization flow consists of
regridding the two data sets to a common grid, applying a space and
time-variant amplitude envelope balance, applying a first pass of
matched filter corrections for global amplitude, bandwidth, phase and
static shift corrections, followed by a second pass of constrained
space-variant matched filter operators, and a final warp function to
dynamically align mispositioned events. Difference sections obtained
by subtracting the two data sets after each step of the
cross-equalization processing flow show a progressive reduction of
non-repeatable noise and a simultaneous improvement in time-lapse
reservoir signal.