Sequestration Test to Demonstrate CO2 Storage, Increase Oil Production

July 3, 2006

The Energy and Environmental Research Center at the University of North Dakota Plains CO2 Reduction Partnership, in collaboration with its industry partner Apache Canada Ltd. and the Alberta Department of Energy and Natural Resources Canada, is evaluating the potential for geological sequestration of carbon dioxide as part of an acid gas stream that also includes high concentrations of hydrogen sulfide.

The gas will be obtained from the Zama gas-processing plant, owned and operated by Apache Canada Ltd., and will be injected 4,900 feet below the surface into the Zama oil field, located about 10 miles from the plant. The Zama geology includes steep, mound-like carbonate structures with an average size of 40 acres and 400 feet in height. Their structure makes them ideal traps for storing these gases.

The gas will be injected into a well at a rate of 100 tons per day over the next two years. With various types of verification equipment being used, the partners will monitor resistivity, changes in bulk fluid density, pH, pressure and temperature. This project has the ability to sequester 67,000 tons of carbon dioxide annually.

The Zama test will help determine the impact that high concentrations of hydrogen sulfide may have on carbon dioxide integrity, as well as enhanced oil recovery. Results will provide valuable data on the accuracy of carbon dioxide storage capacity predictions and also aid in validating geologic sequestration testing under acid gas conditions.

The injection process will give an added economic benefit as well. Acid gas injection allows for large volumes of carbon dioxide to be sequestered, eliminating the need to use more expensive disposal methods for hydrogen sulfide in the gas stream, and simultaneously producing oil from these formations that would otherwise be unrecoverable.

This test will be one of 25 performed by the Regional Carbon Sequestration Partnerships designed to validate opportunities for geologic sequestration throughout North America.

Source: U.S. Department of Energy (DOE) Office of Fossil Energy.