CCS and Power Systems
Carbon Storage - Regional Carbon Sequestration Partnerships/Injection Projects
Enhanced Coal Bed Methane Production and Sequestration of CO2 in Unmineable Coal Seams
Project No: FC26-01NT41148
CONSOL Energy Inc. (CONSOL) is demonstrating a horizontal drilling and production process that reduces potential methane emissions from coal mining, produces usable methane (natural gas), and creates a geologic storage option for carbon dioxide (CO2) in unmineable coal seams. The CONSOL project has employed horizontal drilling to drain coalbed methane (CBM) from a mineable coal seam and an underlying unmineable coal seam. After drainage of 50-60 percent of the CBM, two of the wells are being used for CO2 injection (Figure 1) to stimulate additional methane production and store the CO2 in the unmineable seam. The technique starts with drilling a vertical well from the surface followed by a guided borehole that extends up to 3,000 feet horizontally in the coal seam, allowing for production over a large area from relatively few surface locations.
The project involves development of two stacked coal seams in a 200-acre area (Figure 2). The lower, unmineable seam was initially degassed and is now being injected with CO2 to increase both storage and methane production in nearby production wells. The upper, mineable seam was degassed to produce coalbed methane, thus avoiding methane emissions when the seam is mined. The upper, mineable seam is isolated from the lower, unmineable seam to prevent CO2 migration from the unmineable seam into the mineable seam.