Session AF: Porous Media I: CO2 Sequestration
8:00 AM–9:57 AM, Sunday, November 21, 2010
Long Beach Convention Center Room: 103A
Chair: Carlos Hidrovo, University of Texas at Austin
Abstract ID: BAPS.2010.DFD.AF.6
Abstract: AF.00006 : Convective dissolution in porous media
9:05 AM–9:18 AM
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Abstract 
Authors:
Jerome Neufeld
(University of Cambridge)
Marc Hesse
(University of Texas at Austin)
Amir Riaz
(University of Maryland)
Mark Hallworth
(University of Cambridge)
Hamdi Tchelepi
(Stanford University)
Herbert Huppert
(University of Cambridge)
Motivated by the geological storage of buoyant carbon dioxide (CO$_2$) we investigate dissolution of CO$_2$ into brine which increases security of storage over time. The rate of CO$_2$ dissolution is determined by convection in the brine driven by the increase of brine density with CO$_2$ saturation. We present a new analogue fluid system that reproduces the nonlinear density behaviour of CO$_2$ and brine. We show that the convective flux is proportional to the Rayleigh number to the $4/5$ power through a combination of laboratory experiments and high-resolution numerical simulations, in contrast with a classical linear relationship. This relationship allows us to extrapolate from the laboratory scale to geophysical scales. A scaling argument that incorporates the effect of the large-scale flow on mixing at the CO$_2$-brine interface confirms this nonlinear relationship for the convective flux and provides a physical picture of high Rayleigh number convection in a porous medium. The resultant model makes quantitative predictions of the CO$_2$ dissolution rates in natural and anthropogenic CO$_2$ accumulations. For example, at the Sleipner field we estimate a dissolution rate of roughly 10\% of the annual injected mass suggesting that storage security is significantly enhanced.
To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2010.DFD.AF.6