DOE project tests combining carbon dioxide storage, CBM recovery

Nick Snow
OGJ Washington Editor

WASHINGTON, DC, June 21 -- A US Department of Energy regional partnership has begun field testing the potential for combining geologic carbon dioxide storage with enhanced coalbed methane recovery at an Alabama site, DOE’s Fossil Energy Office announced.

FEO said members of the Southeast Regional Carbon Sequestration Partnership (Secarb) are injecting CO₂ into a CBM well in Tuscaloosa County to determine if mature CBM reservoirs are capable of receiving and adsorbing significant CO₂ volumes. Participants in the field test, known as the Black Warrior CO₂ Storage Project, include Southern Co., El Paso Exploration & Production Co., the Geological Survey of Alabama, and the University of Alabama.

The participants began injecting CO₂ on June 15, and plan to inject 240 tons over 45-60 days, according to DOE. It said that a well operated by El Paso E&P had been converted earlier for CO₂ injection, and four wells were drilled to monitor reservoir pressure, gas composition, water quality, and the CO₂ plume.

DOE said the site was selected because it was representative of the 23,000-sq-mile Black Warrior basin in northwestern Alabama and northeastern Mississippi. Coal in the basin has the potential to sequester 1.1-2.3 GT of CO₂, or about the amount emitted by Alabama’s coal-fired power plants over 20 years, it said. Enhanced CBM recovery combined with CO₂ storage could squeeze another 1.5 tcf of gas from these coal seams, it suggested.

The project will monitor injected CO₂ at and below the surface to ensure that storage is safe and permanent, DOE said. Three deep subsurface monitoring wells will use pressure transducers and fluid sampling tubes to monitor the coal groups. While CO₂ is injected into one coal seam, the others should display a minimal pressure response if the CO₂ remains in the original coalbed.

Pressures will also be monitored inside the well to ensure that there are no leaks, DOE said. Shallow groundwater and soil gas monitoring will provide important information which can be used to evaluate whether Black Warrior basin carbon sequestration and enhanced CBM recovery is environmentally safe, it indicated.

DOE created its regional carbon sequestration program in 2003 to determine which of numerous carbon storage approaches are best suited for different regions of the country. The partnership program completed its characterization phase in 2005 and is in its validation phase, which runs from 2005 to 2010 Sunoco and generally includes small-scale field tests such as the Black Warrior Basin CO2 Storage Project. The final phase, involving development, will run from 2007 to 2018 and include large-volume carbon storage tests. The National Energy Technology Laboratory manages the partnership program for FEO.

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