The
Gulf Coast is an important focus area for research on modern deltas,
primarily
because of the economic importance of deltas in this region as oil and
gas
reservoirs. The Gum Hollow Delta,
located along the north shore of Nueces Bay, west of Portland, Texas,
is an
ideal candidate for a modern analog of a wave-reworked deltaic
succession, as its scale is
measurable but large enough to model on a reservoir scale.
Analog
studies of modern depositional environments provide significant data of
physical attributes, which ultimately contribute a better understanding
of the
internal architecture of these complexes, especially the heterogeneity
of flow
units within reservoirs which provide physical data for modeling
reservoirs. A large proportion of
hydrocarbon reserves are contained in rocks formed by ancient deltas;
these
reservoirs often have complex internal architecture and
properties.
By applying a modern analog, the Gum Hollow
Delta, the depositional processes and geometries of such deltaic
deposits can
be examined to improve subsurface interpretations.
A
study on the Gum Hollow Delta was performed by J.H. McGowen in 1971,
but the
main focus of his study was to determine the mechanics of fan
development and
the relationships between sedimentary processes and structures.
Further, this data set documented changes in
form of the delta and related these changes to specific geological
processes. To date, no studies have
been attempted to examine the detailed internal architecture of a
typical modern delta
succession. An understanding of the
internal facies and architecture of the Gum Hollow Delta will provide
much
needed information about the evolution of modern wave-dominated delta
systems. The application of this obtained data to
subsurface interpretations will help to better understand groundwater
and
hydrocarbon reservoirs that originated from similar deltaic successions.
In
this study, the Gum Hollow Delta will be revisited with a different
approach
than McGowen. Since this study, there
has been a great advancement in technology.
A 3-D ground-penetrating radar survey will be collected across the
entire
delta. This GPR data will be integrated
with sedimentological data obtained from vibracores to establish the
internal
facies and architecture of the delta.
The interpretation of this geophysical and sedimentological information
will be critical data sources to accurately model this modern delta.