HR: 1340h
AN: GC13A-1223    [Abstracts]
TI: The Significance of Dipping Bed Effects on CO₂ Plume Migration
AU: * Gasda, S E
EM: sgasda@princeton.edu
AF: Dept of Civil and Env Eng, Princeton University, Princeton, NJ 08540 United States
AU: Celia, M A
EM: celia@princeton.edu
AF: Dept of Civil and Env Eng, Princeton University, Princeton, NJ 08540 United States
AU: Nordbotten, J M
EM: janmn@mi.uib.no
AF: University of Bergen, Dept of Mathematics Johannes Bruns Gate 12, Bergen, 5008 Norway
AB: Recent investigations regarding CO₂ sequestration in deep, saline aquifers have focused on characterization of the injected plume, its migration within the aquifer over time, and possible leakage out of the aquifer. As part of our efforts to understand and quantify leakage potential in CO₂ storage systems, a semi-analytical solution has been developed that describes the plume shape evolution as well the amount of leakage, with a focus on leakage along abandoned wells. The semi-analytical solutions require a number of simplifying assumptions, including a perfectly horizontal aquifer, negligible capillary pressure, and symmetry of the injection plume. Each of these assumptions can be tested systematically through application of more general numerical simulators. For example, in typical sedimentary basins, it is common to have sloping aquifers with a vertical rise of up to 3-4 km over the total horizontal length of the basin (hundreds of kilometers). Although the slope may only be 1% or less, the effects on the upward migration of the CO₂ plume may be significant over the time scales appropriate for carbon sequestration. Similarly, the role of capillarity in these systems may be significant due to capillary diffusion or to capillary exclusion. In this study, we use a general two-phase numerical simulator to assess the limitations of the assumptions required to derive semi-analytical solutions to these systems. For example, we can simulate injection of CO₂ into a confined saline aquifer for an extended period (we have used 30 years) and examine the effect of different degrees of slope on the centroid and maximum upslope extent of the plume. These measures of plume asymmetry can then be related to an appropriate dimensionless grouping that takes into account the fluid properties and aquifer characteristics. In this presentation we will present results from these simulations and discuss their implications regarding the extent to which CO₂ injection systems can be simplified.
DE: 1600 GLOBAL CHANGE
SC: Global Climate Change [GC]
MN: Fall Meeting 2005