Skip to content Skip to navigation

SCCS Autumn Seminar: CO2 Plume Migration and Dissolution in Layered Reservoirs

Date and Time: 
November 28, 2018 - 12:30pm
Location: 
Green Earth Sciences Building, Room 14

Abstract:
In carbon capture and sequestration (CCS) projects, the presence of layered permeability heterogeneity can strongly affect the migration of the supercritical CO2 plume and CO2 dissolution. By conducting a systematic study of plume migration in layered reservoirs with a  wide range of permeability contrast between the layers, we show that the relationship between CO2 plume footprint and permeability contrast can be divided into three distinct regimes. For moderate permeability contrasts from 1 to 5, the presence of different layers has little impact on plume migration. As the permeability contrast increases from 5 to 50, the plume footprint decreases progressively. Finally, in the event of extreme permeability contrast (>50), the footprint is independent of the heterogeneity, however, the footprint is significantly smaller than  for the cases with lower contrast ratios. Overall, the footprint of the plume can vary by more than 2-fold, with large implications for monitoring, access to property sites, and other regulatory issues. The mass fraction of CO2 dissolution can vary up to 2-fold, from about 12 to 25% of the injected CO2, depending on the degree of heterogeneity. Interestingly, there is not a monotonic relationship between the fraction of CO2 that dissolves and the degree of permeability contrast. Maximum dissolution occurs when the permeability contrast is about 50. We also show that the common practice of using permeability anisotropy to simulate multiphase flows in layered reservoirs works quite well in terms of plume footprint for permeability contrasts of up to 100 and anisotropy ratios of up to 26, but large errors occurs at more extreme contrasts.

Contact Email: 
anshula@stanford.edu
Event Sponsor: 
sccs