Introduction to CRG

The CRG program has run continuously since 1992 and has produced numerous outside and BEG publications on clastic reservoir characterization, sequence stratigraphy, petrophysics, geostatistics, and petroleum engineering. We provide research results to sponsor companies in the form of annual review meetings, field trips, executive slide sets, preprints of publications, short courses on geologic and engineering aspects of our research, and through a mentoring program working hands on with industry staff and data sets. In addition, much of our results are posted in this web site.

The sponsorship currently has a strong interest in tidally-influenced deltaic systems and shorelines and provides support for 2-3 professional staff and varying numbers of graduate student research assistants, plus strong computer and graphics support. A geologist/geophysicist (Wood), and a reservoir geologist/sedimentary petrologist (Dutton) form our core group. Research assistant Gao specializes in web design and image construction. All staff have extensive industry experience or have worked closely with industry and are well aware of the challenges and questions facing geoscientists and engineers.

Each year we combine industry input with our own ongoing research plans to develop a set of key research topics. These are focused on investigation of clastic depositional systems, their component architecture and processes, and the ways those elements influence exploration and development in clastic reservoir systems. Research has two principal directions: a well-established program of outcrop characterization and a program in subsurface characterization.

The goal of outcrop study is to quantify interrelationships among facies architecture, diagenesis, and rock properties within a sequence-based framework. Data types collected include detailed outcrop logs of facies, grain size, bioturbation, bedding character, gamma scans, permeability measurements, and sonic velocity data. Outcrops provide specific, unambiguous data on sandstone-body geometry, character and continuity of bounding surfaces, and on internal facies architecture of sandstones and nonreservoir rock types.

Outcrop study areas are selected to correspond with close occurrence of subsurface data through the study intervals. Outcrop observations are combined with closely adjacent subsurface well-log and core data to expand understanding of the three-dimensional architecture of the system. Gamma scans and permeability logs taken on the outcrop provide a direct link between outcrop architectural elements and key surfaces and adjacent subsurface equivalents.
Such integration allows three-dimensional mapping of all levels of reservoir architecture, from architectural elements to sequences. Conventional sonic logs and outcrop velocity measurements provide data to model the seismic response of stratigraphic relationships, key surfaces and facies changes. These approaches not only provide direct analogues for comparison with similar worldwide deposits, but allow development of methodologies for integrating information developed from outcrop with subsurface data sets and improved methods for interpreting, risking, and developing heterogeneous deltaic systems.

The need for quantitative data in a variety of heterolithic reservoir systems has spurred research on the excellent outcrop exposures of the U.S. western interior. CRG research has spent 7 years working in fluvial-deltaic outcrops in the western United States. Study subjects include

Ferron Sandstone

a high-accommodation, fluvial-deltaic depositional system.

Fall River Formation

a low-accommodation, fluvial-estuarine incised-valley deposit and associated wave-dominated deltaic deposits.

Frewens Castle Sandstone

a aggradational, tidally influenced, top-truncated lowstand delta. ·

Sego Sandstone

a progradational, tidally influenced delta and associated incised valley network.

These studies have resulted in both quantitative and qualitative documentation of the generic depositional parameters, character, architecture, sedimentology, petrography, diagenesis, and modeled fluid-flow trends of these systems. These data are contained within the Deltaic Systems Catalog maintained by our research group, a catalog available to members that will continue to grow with future research.

Direct contact with the technical staff of our sponsoring companies is an important aspect of our program. This allows us to test our concepts and methods on real problems while assisting sponsors in developing new reserves. Sponsors are encouraged to contact us with projects that could be mutually beneficial. In addition, Associates can also privately visit the Bureau during the year to discuss specific exploration or development problems or confidential data sets with CRG staff.

Each Associate pays a sponsorship fee of $35,000 per year and receives the same research products each year: (1) access to the Deltaic Systems Catalog, (2) an annual project-review meeting in December, (3) presentation materials and accompanying detailed captions, distributed as hard copy, 35-mm slides, or CD-ROMs of PowerPoint presentations, and a password-protected site on the World Wide Web, (4) all quantitative data in a digital format, (5) preprints of publications, and (6) an annual field trip.

Further information on the Clastic Reservoirs Group is available on two Web sites: (1) a password-protected site for CRG Industrial Associates, which includes digital slide sets, flow-model animations, other digital publications, and abstracts of manuscripts in review for publication and (2) a public site at http://www.beg.utexas.edu/indassoc/crg/index.htm.

If you are interested in becoming a CRG Industrial Associate, or if you have any questions on aspects of the Clastic Reservoirs Group program, please contact: