A Methodology for Assessing the Carbon Sequestration Potential of Deep Saline Aquifers Beneath from Industrial CO₂ Source

Jason W. Deardorff¹, John E. McCray², Genevieve Young³, and Dag Nummedal^1
1Colorado Energy Research Institute, Colorado School of Mines, Golden, CO
²Division of Environmental Science and Engineering, Colorado School of Mines, Golden, CO
³Colorado Geological Survey, Denver, CO

Geologic carbon sequestration involves the capture of carbon dioxide (CO₂) generated from point sources such as coal-burning power plants and its subsequent injection into depleted oil and gas reservoirs, uneconomic coal seams, flood basalts, and deep saline aquifers. In order to impact the global climate, the volume of compressed carbon dioxide that will have to be injected each year is larger than the volume of oil produced from the ground in the same period. Therefore, sequestration in oil and gas reservoirs, whether depleted or producing, represents only a fraction of the storage capacity required over the next century. Deep saline aquifers contain the largest potential storage capacity with low estimations reaching over 1 trillion short tons in North America alone. But due to few existing well penetrations and only recent interest in these aquifers, there exist large uncertainties that make accurate modeling of CO₂ injection into these aquifers difficult and often cost prohibitive with conventional reservoir simulation software. The Colorado Energy Research Institute at the Colorado School of Mines has developed a preliminary screening methodology utilizing established fluid property algorithms and databases, an analytical injection model, and GIS technology to assess the potential of deep saline aquifer horizons for carbon sequestration. Expected ranges of geologic conditions, reservoir parameters, and specific CO₂ input requirements are entered into a Microsoft Excel spreadsheet to calculate best/worst case scenarios for plume size. GIS technology is then used to determine the number of expected oil and gas well intersections in a given aquifer. The methodology will be applied to the site of a proposed IGCC (carbon capture) power plant in the Denver-Julesburg Basin and the results of this assessment will be presented.

AAPG Search and Discovery Article #90092©2009 AAPG Rocky Mountain Section, July 9-11, 2008, Denver, Colorado