Oil & Natural Gas Projects
Exploration and Production Technologies
Reviving Abandoned Reservoirs with High-Pressure Air Injection: Application
in a Fractured and Karsted Dolomite Reservoir
The project goal was to evaluate the applicability of high-pressure air injection (HPAI) in revitalizing a nearly abandoned carbonate oil reservoir in the Permian Basin of West Texas. Successful results can be applied to similar oil reservoirs in other areas of the Permian Basin.
Bureau of Economic Geology
University of Texas
Goldrus Producing Company
The Lower Ellenburger carbonate reservoir under study has been demonstrated
to be a complex fractured reservoir where the fractures were produced by karst
(collapsed paleocave) processes. A simulation model was developed based on available
laboratory and field data. The model was utilized to perform waterflood and
air injection simulation runs in stratified and fractured reservoir environments.
The results obtained after an extensive history-matching exercise using combustion
tube data indicate that the reservoir under study is a very good candidate for
HPAI. Initial field results indicated that HPAI does work in the field. Early
results from the pilot demonstrate that the technology is a success in the reservoir.
High-pressure air was injected in a test well, and results indicated that combustion
took place and a response was recorded in the producing well.
This program is designed to help oil and gas operators effectively apply an
exciting new technology that has a huge potential for dramatically increasing
the recovery of oil from underexploited, mature carbonate reservoirs. HPAI previously
has been applied in heavy oil reservoirs but only rarely attempted in light
oil reservoirs, where a much greater remaining oil resource lies. Researchers
are testing this innovative technology in a carbonate reservoir that, because
of pressure depletion, has been nearly abandoned. Success from this study will
stimulate application throughout the Permian Basin.
In order to apply HPAI to a reservoir, the stratigraphic architecture must be
well-known to understand the movement of fluids within a reservoir. This was
accomplished by integrating core and wireline-log data. Laboratory testing has
been carried out to quantitatively assess mechanical alterations of reservoir
material by the elevated temperatures near the combustion front. Goldrus Producing
Company, has demonstrated the effectiveness of HPAI in Ellenburger reservoir
rocks in laboratory tests. With the support of the lease royalty owner, researchers
successfully deployed a field pilot, consisting of a vertical air-injection
well and a horizontal producing well, to test the technology in an actual field
The primary objectives of the project are to develop, test, and document optimal
methods for deploying HPAI technology to recover remaining hydrocarbons from
an abandoned carbonate reservoir. This will be accomplished in three phases
The reservoir characterization phase (Phase 1) consists of 1) analysis of the
reservoir stratigraphy and facies, 2) characterization and modeling of reservoir
matrix petrophysical properties, 3) characterization and modeling of reservoir
fractures, and 4) characterization and modeling of the effects of HPAI on reservoir
mechanical properties (deformation, strength, and fluid transport behavior)
for both matrix and fractures.
The final phase of the project (Phase 3, Technology Transfer) is devoted to compiling, reporting, and distributing the results of the completed project to industry.
Current Status (July 2007)
The reservoir characterization phase (Phase 1) of the project is on schedule, but additional advances depend on obtaining new core material. New cores were scheduled by Goldrus, but they have been canceled. A larger demonstration phase (Phase II) has been cancelled by Goldrus because of funding problems. Goldrus was active in searching for partners to help finance the project.. Researchers have presented results in oral presentations and papers. The project has ended.
Project Start: October 1, 2002
Project End: September 30, 2006
Anticipated DOE Contribution: $416,805
Performer Contribution: $83,361 (20% of total)
NETL - Virginia Weyland (firstname.lastname@example.org or 918-699-2041)
BEG - Robert Loucks (email@example.com or 512-471-0366)
Combs, D.M., Loucks, R.G., and Ruppel, S.C., Lower Ordovician Ellenburger Group
collapsed paleocave facies and associated pore network in the Barnhart field,
Texas, in Hunt, T.J., and Lufholm, P.H., The Permian Basin: Back to Basics,
West Texas Geological Society Fall Symposium, West Texas Geological Society
Publication #03-112, 2003, p. 397-418.
Dhiraj, Dembla, Stimulating enhanced oil recovery (EOR) by high-pressure air
injection (HPAI) in west Texas light oil reservoir, 2004, University of Texas
at Austin Petroleum Department thesis, 123 p.
Barnhart field location.
Three samples of Lower Ellenburger carbonate reservoir rock displaying signs
of karst-related fracturing. The sample at left shows multiple generations of
karst-related fractures. The middle sample shows interclast pores related to
karst processes. The sample at right shows crackle breccia pores related to