SECARB Field
Test for CO2 Sequestration in Coalbed
Methane Reservoirs of the Black
Pashin, Jack1,
Peter Clark2, Richard Esposito3 (1) Geological Survey of
Alabama, Tuscaloosa, AL (2) University of Alabama, Tuscaloosa, AL (3) Southern
Company, Birmingham, AL
Assessment of the CO2
sequestration and enhanced recovery potential of coalbed
methane reservoirs in the Black Warrior basin of Alabama indicates that more
than 5.9 Tcf of CO2 can be sequestered
while increasing coalbed methane reserves by more
than 20 percent. The Black Warrior coalbed methane
fields are approaching maturity, and CO2-enhanced coalbed methane recovery has potential to add decades of
life to these fields.
The Southeastern Regional Carbon
Sequestration Partnership (SECARB) will be conducting a field test in the Black
Warrior basin, where multiple coal seams are dispersed through a thick stratigraphic section. The permeability of coal decreases
exponentially with depth, thus strategies need to be developed to manage
injection into multiple coal seams with a broad range of reservoir properties.
Reservoir testing will consist of a series of production and injection-falloff
tests in three coal zones, and deep monitoring of pressure will be conducted
through packer and interference tests in three observation wells. Baseline
reservoir simulations will aid in the design of the testing program, and
follow-up simulations will be performed for history matching of the results.
Soil-gas composition will be monitored to
determine if seepage of injected gas occurs and to facilitate the
identification of monitoring protocols that can be applied effectively to
commercial injection and enhanced recovery operations. In addition, stochastic
reservoir modeling software is being developed to characterize multi-phase flow
in fracture networks and to assess environmental risks associated with CO2
injection and enhanced coalbed methane recovery.
AAPG Search and Discover Article #90063©2007 AAPG Annual Convention, Long Beach, California