Geophysical Imaging of Subsalt Geology
Davis W. Ratcliff and David J. Weber
Exploration and production of huge subsalt hydrocarbon accumulations in the
Gulf of Mexico has been an ambitious challenge for many explorationists
throughout the industry. The complexities associated with the three dimensional
nature of salt structures, as well as the highly deformed tops and bottoms of
salt, demand 3-D
Prestack Depth Migration (
3-D
PreSDM) technology in order to
correctly stack and position reflectivity below salt. Application of "large-volume"
3-D
PreSDM techniques has been, and will continue to be, instrumental in
unraveling the structural and stratigraphic complexities of the subsalt
environment. "Large-volume"
3-D
PreSDM technology allows the explorationist to
better assess subsalt exploration and development risk, as well as improve
subsalt explora ion success.
In this paper, we discuss a full-volume 3-D
PreSDM case study that, to our
knowledge, is the largest prestack depth imaging project ever attempted, to date.
The
3-D
PreSDM case study is centered over the Mahogany
Discovery in the Gulf of Mexico's Ship Shoal South Addition Block 349 area.
Information about input and output data coverage, computer run times and
3-D
depth imaging strategies will be discussed. Numerous examples of closely spaced
3-D
prestack depth migrated seismic data will also be shown in order to
demonstrate how "large-volume"
3-D
PreSDM technology improves subsalt imaging, (both
structural and stratigraphic), as well as subsalt prospecting.
AAPG Search and Discover Article #91019©1996 AAPG Convention and Exhibition 19-22 May 1996, San Diego, California