1Chevron USA Production Company
2Chevron Petroleum Technology Company
Abstract: Construction and Use of Multi-Attribute
Cubes for
Structural Interpretation of the Main Pass 299 Salt Dome, Gulf of
Mexico
Structural interpretation around salt domes is often complicated
by imaging problems and the presence of steeply dipping seismic
reflectors and faults of varying orientations. Interpretation using
only
seismic
amplitude and/or amplitude difference (Edge) cubes is
time consuming and can often be misleading. Properly processed
multi-
attribute
cubes which incorporate both the amplitude and the
Edge information contain the data necessary to map faults and
related stratal geometries and allow the interpreter to make more
realistic structural interpretations. In the Main Pass 299 area we
have used
seismic
Edge detection technology and a workflow that
utilizes multiple properties of the
seismic
data to help resolve
small scale faulting adjacent to salt and define untested fault
blocks. Significant business impacts of the application of this
workflow in the Main Pass 299 field include; reduction of
interpretation cycle time, an increased confidence in the
structural interpretation and the delineation of potential unbooked
reserves in an untested fault block.
Three workstation applications for combining seismic
attributes
into a single visual presentation were compared. In-house 3D
interpretation software combines
seismic
attributes by pixel
dithering or a spatial interleaving of the two input cubes. This
process results in decreased resolution of each of the attributes
being combined, but provides the ability to interactively change
the weighting of each
attribute
within the multi-
attribute
cube.
Combination of
seismic
attributes at full resolution using the
properties of color (intensity, hue and saturation) was
accomplished with proprietary software. Combination of
seismic
attributes with commercially available 3D visualization and image
processing software (VoxelGeo) allows the user real time
interactive control over
attribute
weighting at full resolution and
was used to optimize
attribute
weighting parameters and produce an
optimum multi-
attribute
interpretation product for structural
interpretation.
A structural/stratigraphic interpretation workflow utilizing
single (amplitude) and the multi-attribute
(amplitude and amplitude
difference)
seismic
data cube, 3D visualization software and
conventional 2D mapping applications was used for
seismic
interpretation, map generation and prospect evaluation.
Our work has shown that optimizing Edge processing parameters
and color balancing of seismic
attributes in multi-
attribute
cubes
has a significant effect on imaging faults and therefore
interpreting complex structure around salt domes. In Edge
processing the Main Pass 299 data we used dip steering and an
improved difference algorithm that produces higher resolution edges
from the input volume of
seismic
data. The result is a sharper
definition and discrimination of individual faults in steeply
dipping areas adjacent to the salt dome where remaining
development/delineation drill potential exists.
AAPG Search and Discovery Article #90928©1999 AAPG Annual Convention, San Antonio, Texas