Simultaneous Joint Inversion as a Salt Detector in South Gabon Land Exploration "Best of EAGE"
Mantovani, Marco 1; Dugoujard, Thierry 2
(1)
WesternGeco, Milan, Italy. (2) Perenco, London, United Kingdom.
In the special case of non-Gardner bodies (i.e., salts) inside a
standard Gardner background setting, simultaneous joint inversion offers a
quantitative approach to QC on interpreted layer boundaries for such a
formation. Misplacements or boundary errors in salt horizons result in
simultaneous joint inversion velocity and density outputs as inconsistencies
that may, therefore, indicate layer geometry corrections to otherwise regular
solutions. In the presented case, a boundary of validity between a velocity and
resistivity positive and negative correlation is detected by simultaneous joint
inversion, and used as salt top/bottom edge indicator. For hydrocarbon
exploration in the South Gabon sub-basin, because the seismic method alone was
failing in salt and subsalt imaging, Perenco hypothesized that gravity data
could be utilized to enhance the imaging of pre-salt seismic reflectors by
providing additional input for prestack
depth
migration
. Two vintage 2D seismic
lines were reprocessed utilizing the technology simultaneous joint inversion
technology.
AAPG Search and Discovery Article #90135©2011 AAPG International Conference and Exhibition, Milan, Italy, 23-26 October 2011.