HR: 1340h
AN: B33A-1012    [Abstracts]
TI: Analytical Modeling of CO₂ Storage and Enhanced Coal Bed Methane Recovery
AU: * Seto, C J
EM: cjseto@pangea.stanford.edu
AF: Stanford University, Department of Petroleum Engineering Green Earth Sciences Building Stanford University, Stanford, CA 94305 United States
AU: Jessen, K
EM: krisj@stanford.edu
AF: Stanford University, Department of Petroleum Engineering Green Earth Sciences Building Stanford University, Stanford, CA 94305 United States
AU: Orr, F M
EM: fmorr@stanford.edu
AF: Stanford University, Department of Petroleum Engineering Green Earth Sciences Building Stanford University, Stanford, CA 94305 United States
AB: Injection of CO₂ into deep unminable coal seams is an option for geological storage of CO₂. In these systems, adsorption of gas on the internal surfaces of the coal is the storage mechanism. In many of these reservoirs, large amounts of CH₄ are adsorbed onto the coal. CO₂ is preferentially adsorbed compared to CH₄, which offers the possibility of desorption and increased recovery of CH₄ from coal without lowering pressure in the coal bed. The interaction between CO₂ sequestration and enhanced CH₄ production makes coal reservoirs interesting candidates for sequestration. We report analytical solutions for one-dimensional, two-phase, three-component flow with adsorption of gas components onto coal surfaces in the absence of dispersion in the flowing phases. The solutions were obtained by the method of characteristics. We present solutions for combined flow of brine, CO₂, and CH₄, with solubility of both gas components in the brine and with adsorption represented by constant equilibrium partition coefficients. The solutions consist of shocks and continuous variations. We show that the arrangements of shocks and rarefactions depends on the relative strength of the adsorption of the gas components. These solutions provide insight into the complex interplay of adsorption, phase behavior and convection in these systems. Improved understanding of the physics of these displacements will aid in developing more efficient and physically accurate techniques for predicting the movement and fate of injected CO₂ in the subsurface.
DE: 1622 Earth system modeling (1225)
DE: 1699 General or miscellaneous
SC: Biogeosciences [B]
MN: Fall Meeting 2005