About This Item

Share This Item

The AAPG/Datapages Combined Publications Database

AAPG Special Volumes

Abstract

Pittenger, Michelle A., Charles T. Feazel, Govert J. Buijs, Ray R. Reid, and Paul W. Johnson, 2012, Evaluation of Knox Supergroup dolostones as a target for carbon dioxide storage in western Kentucky, in J. R. Derby, R. D. Fritz, S. A. Longacre, W. A. Morgan, and C. A. Sternbach, eds., The great American carbonate bank: The geology and economic resources of the Cambrian–Ordovician Sauk megasequence of Laurentia: AAPG Memoir 98, p. 10631076.

DOI:10.1306/13331530M983520

Copyright copy2012 by The American Association of Petroleum Geologists.

Evaluation of Knox Supergroup Dolostones as a Target for Carbon Dioxide Storage in Western Kentucky

Michelle A. Pittenger,1 Charles T. Feazel,2 Govert J. Buijs,3 Ray R. Reid,4 Paul W. Johnson5

1ConocoPhillips, Houston, Texas, U.S.A.
2ConocoPhillips, Houston, Texas, U.S.A.
3ConocoPhillips, Houston, Texas, U.S.A.
4ConocoPhillips, Houston, Texas, U.S.A.
5ConocoPhillips, Houston, Texas, U.S.A.

ACKNOWLEDGMENTS

We thank the Kentucky Geological Survey staff for their help in gathering data, for providing access to cores, and for sharing their expertise on Kentucky geology; ConocoPhillips, Peabody Energy, E.ON U.S., the Commonwealth of Kentucky, the U.S. Department of Energy National Energy Technology Laboratory, and other partners in the Kentucky Consortium for Carbon Storage for financial support; and Gary Myers, Al Shultz, James Vasquez, and Scott Rennie, our ConocoPhillips colleagues, for their expertise and support.

ABSTRACT

Much like an exploration play, defining a carbon dioxide (CO2) storage target starts with understanding the subsurface. This requires the integration of all available data, from core descriptions to seismic interpretation. Unfortunately, in the areas and reservoirs not traditionally explored for oil and gas, these data are rare to nonexistent. The Cambrian–Ordovician Knox Supergroup dolostones of western Kentucky qualify as one of these types of potential injection targets. With a database of about 25 well logs, a loose two-dimensional (2-D) seismic grid, a few whole cores, and a few well tests, a geologic model of the Knox in western Kentucky was constructed to help understand the potential for CO2 storage in these rocks.

Initially, ideas for porosity development in the predominantly tight Knox dolostones were based on geologic models of the age-equivalent Ellenburger and Arbuckle Formations. In these formations, karsting plays a dominant role. Evaluation of several Knox whole cores, however, indicated only minor epikarst zones in intervals with very low porosity. Most of the porosity development is associated with large dolomite crystal-lined vugs that are interpreted to have precipitated from hydrothermal fluids. Borehole image logs also seem to point toward vugs and fractures as significant contributors to porosity.

Interpreted core and log data were integrated with 2-D seismic interpretations to produce a geocellular model that was used for flow simulation of potential CO2 injection volumes and rates within the Knox Supergroup dolostones. Initial indications are that the Knox Supergroup dolostones have the potential to accept the large volumes of supercritical CO2 necessary for a CO2 storage site, although a significant number of wells may be required. To further assess this model, the Kentucky Consortium for Carbon Storage drilled a well in 2009 to test the CO2 injection capacity of the Knox Supergroup and potential secondary targets. Further evaluation of the sealing capacity of the overlying tight carbonates and shales was also done using whole cores taken in this test well to assess their ability to permanently contain injected supercritical CO2.

Pay-Per-View Purchase Options

The article is available through a document delivery service. Explain these Purchase Options.

Watermarked PDF Document: $14
Open PDF Document: $24