WASHINGTON, D. C. — A team from the U.S. Department of Energy's (DOE) Southeast Regional Carbon Sequestration Partnership (SECARB) is using scientific instrumentation, installed nearly two miles beneath the surface of the earth, to track the movement of carbon dioxide (CO2) being injected for oil recovery. This research effort will provide valuable insight into both the requirements of the instrumentation necessary to ensure the safe storage of CO2 underground, and the geological formations that are expected to permanently store greenhouse gas in the Southeast United States.
DOE's SECARB project, led by Southern States Energy Board and hosted by Denbury Resources, began injecting CO2 at a depth of 10,300 feet on July 15, 2008 for enhanced oil recovery (EOR) at the Cranfield oilfield near Natchez, Mississippi. The source of the CO2 is naturally occurring CO2 that is trapped in the subsurface formation known as the Jackson Dome. The CO2, transported by pipeline to the injection site, will be injected at the rate of 250,000 to 500,000 metric tons per year over the next several years. The target geological formation known as the lower Tuscaloosa Formation is representative of the high quality CO2 storage options that exist throughout the Gulf Coast region.
The Chairman of the Southern States Energy Board, Governor Joe Manchin of West Virginia, noted that "the CO2 injection test is a significant step in demonstrating clean coal technologies needed for the reduction of greenhouse gas emissions."
Innovative real-time monitoring of the CO2 injection is being led by the Gulf Coast Carbon Center at the Bureau of Economic Geology, University of Texas at Austin. Monitoring consists of downhole pressure and temperature measurements within both the injection interval and a monitoring interval 400 feet above. Technical focus areas will include: verifying CO2 retention in the injection zone; quantifying storage capacity; and quantifying near- and far-field pressure response to injection.
According to Denbury's Senior Vice President Tracy Evans, "Carbon capture and sequestration of CO2 is not a future technology but is actually occurring today in CO2 enhanced recovery projects such as the Cranfield field. Sequestration of CO2 in enhanced oil recovery projects will provide the bridge to full scale carbon capture and storage of CO2 and can be expanded today, versus waiting for another five or ten years to pass."
The permanence of storage in this formation is well documented by oil and gas that has been trapped for very long time periods. The Tuscaloosa Formation lies beneath an area of approximately 46,000 square miles in southern Alabama and Mississippi, the Florida Panhandle, and Louisiana. A conservative estimate by the Massachusetts Institute of Technology has projected the storage capacity for the Tuscaloosa Formation at 10 billion metric tons.
Initiated in 2003, DOE's Regional Carbon Sequestration Partnership Program, managed by the Office of Fossil Energy's National Energy Technology Laboratory, includes seven partnering regions established to determine the best approaches for capturing and permanently storing CO2, a greenhouse gas that contributes to global climate change. The partnerships are made up of state agencies, universities, private companies, and nonprofit organizations that form the core of a nationwide network helping to establish the most suitable technologies, regulations, and infrastructure needs for large scale carbon capture and storage. The partnerships include more than 350 organizations, spanning 42 states, three Indian nations, and four Canadian provinces.
SECARB represents 13 southeastern states (AL, AR, FL, GA, KY, LA, MS, NC, SC, TN, TX, VA, and WV) and more than 100 partners and stakeholders. The Cranfield test is one of four pilot tests that the partnership is sponsoring for the Validation Phase of the project. In this phase, multiple sequestration sites and technologies are being validated in preparation for large scale injection that will occur in the Deployment Phase.