The SECARB Program is divided into three phases. Phase I (2003-2005) focused on characterizing the geology and potential terrestrial sequestration options in the Southeast, culminating in the development of an action plan for small-scale geologic carbon sequestration field demonstrations.
Phase II: Validation
SECARB successfully completed its Phase II Validation program (2005-2010). The team implemented the action plan from Phase I and validated various technologies with small-scale injections in the field. Phase II includes field tests in four locations.
Gulf Coast Stacked Storage Project
Enhanced oil recovery (EOR) stacked formations along the Gulf Coast are a prime target area for geologic storage of carbon dioxide. Sequestration in these formations can help the U. S. reach future national emissions reduction targets. SECARB’s research estimated 34 billion metric tonnes of potential storage capacity in the region’s depleted oil and natural gas fields.
The Cranfield Oilfield in Southwest Mississippi, owned and operated by Denbury Resources, is the site of the Gulf Coast Stacked Storage Project. The Gulf Coast Carbon Center at The University of Texas at Austin leads the local effort for SECARB. Injection operations began at SECARB’s Gulf Coast Stacked Storage Project in July 2008 and concluded in December 2010. The objective is to demonstrate the concept of phased use of subsurface volumes, combining early use of CO2 for enhanced oil recovery with later injection into underlying or adjacent brine formations.
The advantages of this phased development are short-term, large-volume injection with immediate commercial benefit to support research and infrastructure development, followed by use of underlying or adjacent brine-bearing formations for large-volume, long-term storage.
Download: Gulf Coast Stacked Storage Project Fact Sheet »
Saline Reservoir Field Test: Mississippi Test Site
Saline formations are the primary CO2 geologic storage options for the SECARB region because so many underlie power plants in the area. In fact, SECARB’s research estimated a total of 2,274 billion metric tonnes of potential sequestration in saline formations in the region underlie Alabama, Florida, Louisiana, Mississippi, East Texas, and Tennessee. The Mississippi Test Site project was successfully conducted in October 2008 and examined a regionally significant deep saline reservoir for geological storage of CO2. In this area, the Massive Sand Unit of the Lower Tuscaloosa Formation has been identified as a high capacity CO2 storage option. Mississippi Power Company’s Victor J. Daniel Power Plant, located near Escatawpa, Mississippi, was the site for the demonstration. The project team is led by the Electric Power Research Institute and Southern Company.
To assure a safe, secure and publicly accepted field test, the Mississippi Test Site project has provided the essential foundation of technical knowledge for full-scale, commercial implementation of CO2 storage activities. This includes: constructing geological and reservoir maps to further assess the site; conducting reservoir simulations to estimate CO2 injection rates, storage capacity and long-term fate of injected CO2; addressing state and local regulatory regimes for permitting the site; fostering public education and outreach to build acceptance; injecting up to 3,000 tons of CO2; and conducting baseline and long-term monitoring to establish the security of the CO2 plume.
Coal Seam Project: Central Appalachian Basin
Coal seams are among the most attractive potential CO2 sinks occurring in the Southeastern United States, where a prolific coalbed methane industry, which has produced more than 2.3 trillion standard cubic feet (Tscf) of natural gas, is approaching maturity. CO2 sequestration in unmineable coal seams can produce enhanced coalbed methane to help offset sequestration costs. An estimated 82.1 billion metric tonnes of potential storage capacity exists in the region’s unmineable coal seams. There are two SECARB Phase II field tests. The first was completed in February 2009 and utilized an existing CNX Gas well located in Russell County, Virginia, for CO2 injection. The Virginia Center for Coal and Energy Research at Virginia Tech managed this project.
On August 18, 2008, Virginia Congressman Rick Boucher, jointly with the U.S. Department of Energy’s Acting Assistant Secretary of Fossil Energy James Slutz, kicked-off the start of the Central Appalachian Coal Seam Project as part of a successful groundbreaking event with local, regional and national stakeholders attending. Injection operations were conducted during January and February of 2009. The project met its objectives to assess the sequestration potential of coalbed methane reservoirs as geologic sinks; verify the sequestration capacity and performance of mature CBM reservoirs in the Central Appalachian Basin through injection falloff and production testing; and implement subsurface monitoring programs. These tests demonstrated geologic sequestration into Appalachian coals as a safe and permanent method to mitigate greenhouse gas emissions. The objectives of the project are directly related to the following tasks: expanded geologic characterization; pilot site selection; reservoir modeling; corehole drilling and evaluation; pilot preparation and risk analysis; pilot testing and injection operations; data interpretation and assessment; and public outreach and technology transfer.
Coal Seam Project: Black Warrior Basin
Similar to the demonstration in Central Appalachia, the principal objectives of the SECARB Black Warrior Basin Coal Seam Project are to determine if sequestration of carbon dioxide in mature coalbed methane reservoirs is a safe and effective method to mitigate greenhouse gas emissions; and to determine if sufficient injectivity exists to efficiently drive CO2-enhanced coalbed methane recovery. Coalbed methane is produced from multiple thin coal seams (0.3 to 2.0 meters) distributed through more than 300 meters of section in the Black Warrior Basin of Alabama. Coal is an extremely stress-sensitive rock type, and permeability can decrease by as much as four orders of magnitude from the surface to depths as shallow as 700 meters. Coal, moreover, is an extremely heterogeneous reservoir, and permeability can vary by more than an order of magnitude at a given depth. Accordingly, procedures and technologies need to be developed to manage reservoirs with properties that vary greatly from seam to seam. This field test is intended to be the first step in this process.
El Paso Exploration and Production donated a well to the SECARB team for CO2 injection. Four wells were drilled to monitor reservoir pressure, gas composition, water quality, and the CO2 plume. The targeted coal seams are in the Pratt, Mary Lee, and Black Creek Coal groups within the upper Pottsville Formation and range from 940 feet to 1,800 feet in depth and from 1 foot to 6 feet in thickness. Two hundred and forty (240) tons of CO2 was injected between June 15 and August 31, 2010. The site is located near Tuscaloosa, Alabama.
Phase III: Development
SECARB began a ten-year Phase III program in October 2007. Early data collection, through Phase II efforts, has shown that the Lower Tuscaloosa Massive Sand Unit is a large, regionally extensive saline formation with potential to hold centuries of CO2 emissions in the Southeast. Continued characterization efforts, within the scope of Phase III, indicate that a multitude of Cretaceous-age sandstone units (saline reservoirs) of the Paluxy Formation, Washita-Fredericksburg interval, Tuscaloosa Group, and Eutaw Formation are suitable for safe, long-term geologic storage of CO2.
SECARB’s Phase III projects will further test the Tuscaloosa and Paluxy geologic formations, respectively, at two sites: the “Early Test” at Cranfield Oilfield, located near Natchez, Mississippi; and the “Anthropogenic Test” at the Citronelle injection site (Citronelle, Alabama) near Southern Company’s CO2 capture test location at Plant Barry.
The first project, or “Early Test,” will inject 1.4 million tonnes of CO2 per year for 18 months. Phase III injection at Cranfield began in April 2009, utilizing CO2 transported by pipeline from a naturally occurring source (Jackson Dome) near Jackson, Mississippi and delivered by Denbury Resources’ CO2 pipeline.
Download: Early Test Fact Sheet »
The second project, or “Anthropogenic Test,” is the world’s first fully integrated carbon dioxide capture, transportation, and geologic storage project utilizing CO2 from a coal-fired power plant. Under separate funding, the CO2 is captured at Alabama Power Company’s James E. Barry Electric Generating Plant located in Bucks, Alabama, and transported by pipeline and sequestered within a the saline Paluxy Formation at the nearby Citronelle Oil Field operated by Denbury Resources. During the Anthropogenic Test, Denbury will inject approximately 100,000 to 150,000 tonnes of CO2 per year for up to three years. The SECARB team will deploy an extensive monitoring, verification, and accounting program that will commence pre-, during, and post-injection. CO2 injection began on August 20, 2012. As of August 30, more than 2,000 metric tons of CO2 have been injected and monitored at the site.
Download: Anthropogenic Test Fact Sheet »