Abstract: Integration of Subsurface and Outcrop Analog
Data for
Building Testable, Deterministic Geological Models in a Common
Interpretation Environment: An Example from the Atokan Boonsville
Gas Field, Fort Worth Basin, Texas.
MCCORMICK, DAVID, ANDY REISCHER, JOHN THURMOND, NICHOLAS DRINKWATER, WILLIAM MURPHY, IAN BRYANT, JOHN ORRANGE, PETER CIRILLI, THOMAS VALLEY, ALLISON FAZIO, Schlumberger-Doll Research; DAVID CARR, Consulting Geologist.
A fundamental problem facing the petroleum industry is to effectively use the large and diverse amount of data that is collected in order to define and exploit stratigraphic and structural compartments that contain undrained hydrocarbons. The key is to build data-driven, deterministic geological interpretations to intelligently target infill wells. This approach is fundamentally different from that used in geostatistically-driven approaches which interpolate the sparse data support points without maximizing the value of the data that has been collected or geological knowledge.
We describe a workstation tool and interpretation method for
that allows one to combine, in 3D, well-based interpretation and
quantitative analog
information from fields or outcrops, to make
testable predictions about the location of geological bodies that
are prospective infill drilling locations. This tool combines (1)
3D visualization in a common viewing environment of diverse data
that are viewed at true scale (e.g., 3D surface seismic, vertical
seismic profiles, reservoir simulation results, conventional
wireline and borehole imaging logs, core photographs; (2) a
well-based interpretation environment; and (3) an archive of
digital 3D geological
analog
shapes and textures that one can use
to relate, for example, textures seen in FMI or core images to
those observed in
analog
data (other fields or outcrops). These
shape and texture analogs can then be used to place geological
bodies that can be rescaled and oriented in 3D. Comparison with
seismic data may then support or refute these interpretations..
We have applied this tool to the interpretation of the Atokan
siliciclastic Bend Conglomerate - a mixed siliciclastic carbonate
succession containing deltaic, estuarine, and fluvial valley-fill
sandstone reservoirs. The key to exploitation of this field is
identification of sandstone bodies within the lowstand, incised
valleys, which are commonly less than 2000 feet in width, and 50
feet in thickness. By combining image log, seismic, and outcrop
analog
information in the 3D visualization tool, we have recognized
Bend Conglomerate reservoir sandstone bodies and further, we have
been able to define them in interwell space using fluvial shape
analogs from the tool's digital archives.
The key advantages of this approach are that we preserve
information about the interpretation process and multiple
hypotheses; we see all data at the appropriate scale; and we view
the implications of the deterministic geological interpretations
within the same data volume as our measured data. This provides a
means of capturing and applying geological knowledge of analog
formations, as well as tracking the steps in the interpretation
process.
AAPG Search and Discovery Article #90937©1998 AAPG Annual Convention and Exhibition, Salt Lake City, Utah