Washington, DC - A large-scale carbon dioxide (CO2) storage project in Mississippi has become the fifth worldwide to reach the important milestone of more than 1 million tons injected. As a result, it is helping to both further carbon capture and storage (CCS) as a mitigation strategy for global climate change and move forward G-8 recommendations for launching 20 projects of this type internationally by 2010.
The project, sponsored by the U.S. Department of Energy's (DOE) Office of Fossil Energy (FE), is located at the Cranfield site in Southwestern Mississippi. It is led by the Southeast Regional Carbon Sequestration Partnership (SECARB), one of seven members of the Regional Carbon Sequestration Partnerships Program (RCSP) managed by the Office of Fossil Energy's National Energy Technology Laboratory (NETL). The Cranfield site is operated by Texas-based Denbury Resources Inc., the project's host.
CCS is a group of technologies for capturing and compressing the CO2 emitted by power plants or industrial sites; transporting it; and injecting it into suitable permanent storage sites, such as deep underground formations. It has been increasingly recognized by scientists and nations worldwide as an effective way to both reduce CO2 emissions from existing sources and help avoid future emissions, making it part of a portfolio response to meet atmospheric CO2 reduction goals. Additionally, the G-8 - of which the United States is a part - has endorsed demonstrating CCS by getting at least 20 industrial-scale projects underway, with the goal of broad deployment of the technology by 2020.
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. 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 (MVA) that can be deployed in other CO2 storage projects nationwide.
In hitting the 1-million-ton storage mark, Cranfield now joins four other large-scale (greater than 1 million tons of CO2 over the storage period) sequestration projects currently underway worldwide:
- 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.
The seven RCSP partnerships form a national network that is investigating the CCS approaches best suited for different regions of the country. The partnerships include more than 350 organizations, spanning 43 states, three Indian nations, and four Canadian provinces. NETL is also a project partner in the Weyburn-Midale, Sleipner, and In Salah projects, either through direct contributions or indirect involvement in technology development.