A U.S. Department of Energy (DOE) team of regional partners has begun injecting carbon dioxide (CO2) into coal seams in the Central Appalachian Basin to determine the feasibility of CO2 storage in unmineable coal seams and the potential for enhanced coalbed methane recovery.

The results of the study will be vital in assessing the potential of carbon storage in coal seams as a safe and permanent method to mitigate greenhouse gas emissions while enhancing production of natural gas, the DOE said.   

The DOE’s Southeast Regional Carbon Sequestration Partnership (SECARB) began injecting CO2 at the test site in Russell County, Va., in mid January. An existing coalbed methane well had earlier been converted for CO2 injection, and two wells have been drilled to monitor reservoir pressure, gas composition, and the CO2 plume. The targeted coal seams are in the Pocahontas and Lee formations and range from 1,400 to 2,200 feet in depth and from 0.7 to 3.0 feet in thickness. About 1,000 tons of CO2 will be injected over a 45-day period.

The site was selected because it is representative of the Central Appalachian Basin, an area of about 10,000 square miles located in southern West Virginia and southwestern Virginia, the DOE said. This area has been assessed by researchers to have the capacity to store 1.3 billion tons of CO2 in the coal seams while increasing natural gas production up to 2.5 trillion cubic feet.

The Central Appalachian Basin CO2 Storage Project will explore the concept of multiple use of subsurface storage volume. Injecting CO2 into coal seams boosts coalbed methane recovery, which provides an immediate commercial benefit and offsets infrastructure development costs, while providing long-term storage of CO2 in the formation—a win-win situation.

The project is being coordinated by the Virginia Center for Coal and Energy Research. The center’s director, Dr. Michael Karmis, has praised the gas operator, CNX Gas; the mineral owner, Buckhorn Coal; and the supply vendors, including Praxair and Denbury Resources, for their "tremendous cooperation and support" of the project. "In addition," he said, "I would like to thank the NETL team that has worked with Virginia Tech and Marshall Miller and Associates researchers to establish baseline measurements and develop a comprehensive monitoring program." 

Initiated in 2003, DOE’s Regional Carbon Sequestration Partnership Program now includes seven partnering regions that were 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 is led by the Southern States Energy Board and represents more than 100 partners and stakeholders in 13 southeastern states: Alabama, Arkansas, Florida, Georgia, Kentucky, Louisiana, Mississippi, North Carolina, South Carolina, Tennessee, Texas, Virginia, and West Virginia.

The Central Appalachian Basin CO2 Storage Project is one of four pilot tests that SECARB 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 development phase.

Source: DOE