A federally sponsored large-scale project in Mississippi has become the first in the nation to inject more than 1 million tons of carbon dioxide in an underground formation, the Department of Energy (DOE) announced last week. Only four other projects—in Norway, Canada, and Algeria—have reached the milestone.
The project, sponsored by the DOE’s Office of Fossil Energy, is located at the Cranfield site in southwestern Mississippi. It is led by the Southeast Regional Carbon Sequestration Partnership, one of seven members of the Regional Carbon Sequestration Partnerships Program managed by the Office of Fossil Energy’s National Energy Technology Laboratory. The Cranfield site is operated by Texas-based Denbury Resources Inc., the project’s host.
The Cranfield project combines the use of CO2 injection with enhanced oil recovery (EOR), followed by CO2 injection into deeper and larger-volume brine, or saline, formations. In the EOR process, injected CO2 is used to help increase the amount of crude oil that can be extracted from otherwise depleted or hard-to-reach petroleum formations.
At Cranfield, researchers are using sophisticated instrumentation installed nearly two miles beneath the surface to monitor the injected CO2 and ensure its safe and permanent storage into the Lower Tuscaloosa Formation, the DOE said in a statement last week. This formation is considered representative of the high-quality CO2 storage options available throughout the U.S. Gulf Coast region.
A major accomplishment of the Cranfield project has been successful deployment of “in-zone” (in the injection zone) and "above zone" (above the injection zone) pressure-response monitoring techniques. Real-time data collected since July 2008 has demonstrated these techniques are cost-effective methods for CO2 monitoring, verification, and accounting that can be deployed in other CO2 storage projects nationwide.
Only four other large-scale projects in the world have reached this milestone:
• Sleipner and Snøhvit (Norway)—CO2 stripped from recovered natural gas is injected into separate saline formations below the seabed in the North Sea (Sleipner) and Barents Sea (Snøhvit).
• Weyburn-Midale (Canada)—CO2 from the Dakota Gasification Company in Beulah, N.D., is piped to southeastern Saskatchewan, where it is injected and stored in conjunction with commercial enhanced oil recovery.
• In Salah (Algeria)—CO2 from recovered natural gas is re-injected into the downdip portion of the sandstone reservoir that produces the natural gas.