Hernandez Arciniegas, Gonzalo (2006-08). Simulation assessment of CO2 sequestration potential and enhanced methane recovery in low-rank coalbeds of the Wilcox Group, east-central Texas. Master's Thesis. Thesis uri icon

abstract

  • Carbon dioxide (CO2) from energy consumption is a primary source of greenhouse
    gases. Injection of CO2 from power plants in coalbed reservoirs is a plausible method for
    reducing atmospheric emissions, and it can have the additional benefit of enhancing
    methane recovery from coal. Most previous studies have evaluated the merits of CO2
    disposal in high-rank coals. Low-rank coals in the Gulf Coastal plain, specifically in
    Texas, are possible targets for CO2 sequestration and enhanced methane production.
    This research determines the technical feasibility of CO2 sequestration in Texas low-rank
    coals in the Wilcox Group in east-central Texas and the potential for enhanced coalbed
    methane (ECBM) recovery as an added benefit of sequestration. It includes deterministic
    and probabilistic simulation studies and evaluates both CO2 and flue gas injection
    scenarios.
    Probabilistic simulation results of 100% CO2 injection in an 80-acre 5-spot pattern
    indicate that these coals with average net thickness of 20 ft can store 1.27 to 2.25 Bcf of
    CO2 at depths of 6,200 ft, with an ECBM recovery of 0.48 to 0.85 Bcf. Simulation
    results of 50% CO2 - 50% N2 injection in the same 80-acre 5-spot pattern indicate that
    these coals can store 0.86 to 1.52 Bcf of CO2, with an ECBM recovery of 0.62 to 1.10
    Bcf. Simulation results of flue gas injection (87% N2 - 13% CO2) indicate that these
    same coals can store 0.34 to 0.59 Bcf of CO2, with an ECBM recovery of 0.68 to 1.20
    Bcf. Methane resources and CO2 sequestration potential of low-rank coals of the Wilcox
    Group Lower Calvert Bluff (LCB) formation in east-central Texas are significant.
    Resources from LCB low-rank coals in the Wilcox Group in east-central Texas are
    estimated to be between 6.3 and 13.6 Tcf of methane, with a potential sequestration
    capacity of 1,570 to 2,690 million tons of CO2. Sequestration capacity of the LCB lowrank
    coals in the Wilcox Group in east-central Texas equates to be between 34 and 59
    years of emissions from six power plants in this area.
    These technical results, combined with attractive economic conditions and close
    proximity of many CO2 point sources near unmineable coalbeds, could generate
    significant projects for CO2 sequestration and ECBM production in Texas low-rank
    coals.

ETD Chair

publication date

  • August 2006