Carbon dioxide sequestration: Modeling the diffusive and convective transport under a CO2 cap

Handle URI:
http://hdl.handle.net/10754/564511
Title:
Carbon dioxide sequestration: Modeling the diffusive and convective transport under a CO2 cap
Authors:
Allen, Rebecca; Sun, Shuyu ( 0000-0002-3078-864X )
Abstract:
A rise in carbon dioxide levels from industrial emissions is contributing to the greenhouse effect and global warming. CO2 sequestration in saline aquifers is a strategy to reduce atmospheric CO2 levels. Scientists and researchers rely on numerical simulators to predict CO2 storage by modeling the fluid transport behaviour. Studies have shown that after CO2 is injected into a saline aquifer, undissolved CO2 rises due to buoyant forces and will spread laterally away from the injection site under an area of low permeability. CO2 from this ‘capped' region diffuses into the fluid underlying it, and the resulting CO2-fluid mixture increases in density. This increase in density leads to gravity-driven convection. Accordingly, diffusive-convective transport is important to model since it predicts an enhanced storage capacity of the saline aquifer. This work incorporates the diffusive and convective transport processes into the transport modeling equation, and uses a self-generated code. Discretization of the domain is done with a cell-centered finite difference method. Cases are set up using similar parameters from published literature in order to compare results. Enhanced storage capacity is predicted in this work, similar to work done by others. A difference in the onset of convective transport between this work and published results is noticed and discussed in this paper. A sensitivity analysis is performed on the density model used in this work, and on the diffusivity value assumed. The analysis shows that the density model and diffusivity value is a key component on simulation results. Also, perturbations are added to porosity and permeability in order to see the effect of perturbations on the onset of convection, and results agree with similar findings by others. This work provides a basis for studying other cases, such as the impact of heterogeneity on the diffusion-convective transport. An extension of this work may involve the use of an equation of state to predict CO2 solubility at thermodynamic conditions, and studying the impact of salinity on CO2 solubility.
KAUST Department:
Physical Sciences and Engineering (PSE) Division; Environmental Science and Engineering Program; Earth Science and Engineering Program; Computational Transport Phenomena Lab
Publisher:
Society of Petroleum Engineers (SPE)
Journal:
SPE Saudi Arabia Section Technical Symposium and Exhibition
Conference/Event name:
SPE Saudi Arabia Section Technical Symposium and Exhibition 2012
Issue Date:
2012
DOI:
10.2118/160881-ms
Type:
Conference Paper
ISBN:
9781632667113
Appears in Collections:
Conference Papers; Environmental Science and Engineering Program; Physical Sciences and Engineering (PSE) Division; Earth Science and Engineering Program; Computational Transport Phenomena Lab

Full metadata record

DC FieldValue Language
dc.contributor.authorAllen, Rebeccaen
dc.contributor.authorSun, Shuyuen
dc.date.accessioned2015-08-04T07:02:50Zen
dc.date.available2015-08-04T07:02:50Zen
dc.date.issued2012en
dc.identifier.isbn9781632667113en
dc.identifier.doi10.2118/160881-msen
dc.identifier.urihttp://hdl.handle.net/10754/564511en
dc.description.abstractA rise in carbon dioxide levels from industrial emissions is contributing to the greenhouse effect and global warming. CO2 sequestration in saline aquifers is a strategy to reduce atmospheric CO2 levels. Scientists and researchers rely on numerical simulators to predict CO2 storage by modeling the fluid transport behaviour. Studies have shown that after CO2 is injected into a saline aquifer, undissolved CO2 rises due to buoyant forces and will spread laterally away from the injection site under an area of low permeability. CO2 from this ‘capped' region diffuses into the fluid underlying it, and the resulting CO2-fluid mixture increases in density. This increase in density leads to gravity-driven convection. Accordingly, diffusive-convective transport is important to model since it predicts an enhanced storage capacity of the saline aquifer. This work incorporates the diffusive and convective transport processes into the transport modeling equation, and uses a self-generated code. Discretization of the domain is done with a cell-centered finite difference method. Cases are set up using similar parameters from published literature in order to compare results. Enhanced storage capacity is predicted in this work, similar to work done by others. A difference in the onset of convective transport between this work and published results is noticed and discussed in this paper. A sensitivity analysis is performed on the density model used in this work, and on the diffusivity value assumed. The analysis shows that the density model and diffusivity value is a key component on simulation results. Also, perturbations are added to porosity and permeability in order to see the effect of perturbations on the onset of convection, and results agree with similar findings by others. This work provides a basis for studying other cases, such as the impact of heterogeneity on the diffusion-convective transport. An extension of this work may involve the use of an equation of state to predict CO2 solubility at thermodynamic conditions, and studying the impact of salinity on CO2 solubility.en
dc.publisherSociety of Petroleum Engineers (SPE)en
dc.titleCarbon dioxide sequestration: Modeling the diffusive and convective transport under a CO2 capen
dc.typeConference Paperen
dc.contributor.departmentPhysical Sciences and Engineering (PSE) Divisionen
dc.contributor.departmentEnvironmental Science and Engineering Programen
dc.contributor.departmentEarth Science and Engineering Programen
dc.contributor.departmentComputational Transport Phenomena Laben
dc.identifier.journalSPE Saudi Arabia Section Technical Symposium and Exhibitionen
dc.conference.date8 April 2012 through 11 April 2012en
dc.conference.nameSPE Saudi Arabia Section Technical Symposium and Exhibition 2012en
dc.conference.locationAl-Khobaren
kaust.authorAllen, Rebeccaen
kaust.authorSun, Shuyuen
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