CO 2 breakthrough—Caprock sealing efficiency and integrity for carbon geological storage

Handle URI:
http://hdl.handle.net/10754/625931
Title:
CO 2 breakthrough—Caprock sealing efficiency and integrity for carbon geological storage
Authors:
Espinoza, D. Nicolas; Santamarina, Carlos ( 0000-0001-8708-2827 )
Abstract:
Small pores in high specific surface clay-rich caprocks give rise to high capillary entry pressures and high viscous drag that hinder the migration of buoyant carbon dioxide CO2. We measured the breakthrough pressure and ensuing CO2 permeability through sediment plugs prepared with sand, silt, kaolinite and smectite, and monitored their volumetric deformation using high-pressure oedometer cells. The data show water expulsion and volumetric contraction prior to CO2 breakthrough, followed by preferential CO2 flow thereafter. Our experimental results and data gathered from previous studies highlight the inverse relationship between breakthrough pressure and pore size, as anticipated by Laplace’s equation. In terms of macro-scale parameters, the breakthrough pressure increases as the sediment specific surface increases and the porosity decreases. The breakthrough pressure is usually lower than the values predicted with average pore size estimations; it can reach ∼6.2MPa in argillaceous formations, and 11.2MPa in evaporites. The CO2 permeability after breakthrough is significantly lower than the absolute permeability, but it may increase in time due to water displacement and desiccation. Leakage will be advection-controlled once percolation takes place at most storage sites currently being considered. Diffusive and advective CO2 leaks through non-fractured caprocks will be minor and will not compromise the storage capacity at CO2 injection sites. The “sealing number” and the “stability number” combine the initial fluid pressure, the buoyant pressure caused by the CO2 plume, the capillary breakthrough pressure of the caprock, and the stress conditions at the reservoir depth; these two numbers provide a rapid assessment of potential storage sites. Unexpected CO2 migration patterns emerge due to the inherent spatial variability and structural discontinuities in geological formations; sites with redundant seal layers should be sought for the safe and long-term storage of CO2.
KAUST Department:
Earth Science and Engineering Program
Citation:
Espinoza DN, Santamarina JC (2017) CO 2 breakthrough—Caprock sealing efficiency and integrity for carbon geological storage. International Journal of Greenhouse Gas Control 66: 218–229. Available: http://dx.doi.org/10.1016/j.ijggc.2017.09.019.
Publisher:
Elsevier BV
Journal:
International Journal of Greenhouse Gas Control
Issue Date:
23-Oct-2017
DOI:
10.1016/j.ijggc.2017.09.019
Type:
Article
ISSN:
1750-5836
Sponsors:
This research was performed at the Georgia Institute of Technology with support from the U.S. Department of Energy (DOE) under grant number DE-FE0001826. Complimentary work at The University of Texas at Austin was supported as part of the Center for Frontiers of Subsurface Energy Security (CFSES) funded by the U. S. Department of Energy under Award # DE-SC0001114. Additional support was provided by the The Goizueta Foundation and the KAUST Endowment. Any opinions, findings, conclusions, or recommendations expressed herein are those of the authors and do not necessarily reflect the views of funding organizations.
Additional Links:
http://www.sciencedirect.com/science/article/pii/S1750583617305601
Appears in Collections:
Articles; Earth Science and Engineering Program

Full metadata record

DC FieldValue Language
dc.contributor.authorEspinoza, D. Nicolasen
dc.contributor.authorSantamarina, Carlosen
dc.date.accessioned2017-10-24T10:45:41Z-
dc.date.available2017-10-24T10:45:41Z-
dc.date.issued2017-10-23en
dc.identifier.citationEspinoza DN, Santamarina JC (2017) CO 2 breakthrough—Caprock sealing efficiency and integrity for carbon geological storage. International Journal of Greenhouse Gas Control 66: 218–229. Available: http://dx.doi.org/10.1016/j.ijggc.2017.09.019.en
dc.identifier.issn1750-5836en
dc.identifier.doi10.1016/j.ijggc.2017.09.019en
dc.identifier.urihttp://hdl.handle.net/10754/625931-
dc.description.abstractSmall pores in high specific surface clay-rich caprocks give rise to high capillary entry pressures and high viscous drag that hinder the migration of buoyant carbon dioxide CO2. We measured the breakthrough pressure and ensuing CO2 permeability through sediment plugs prepared with sand, silt, kaolinite and smectite, and monitored their volumetric deformation using high-pressure oedometer cells. The data show water expulsion and volumetric contraction prior to CO2 breakthrough, followed by preferential CO2 flow thereafter. Our experimental results and data gathered from previous studies highlight the inverse relationship between breakthrough pressure and pore size, as anticipated by Laplace’s equation. In terms of macro-scale parameters, the breakthrough pressure increases as the sediment specific surface increases and the porosity decreases. The breakthrough pressure is usually lower than the values predicted with average pore size estimations; it can reach ∼6.2MPa in argillaceous formations, and 11.2MPa in evaporites. The CO2 permeability after breakthrough is significantly lower than the absolute permeability, but it may increase in time due to water displacement and desiccation. Leakage will be advection-controlled once percolation takes place at most storage sites currently being considered. Diffusive and advective CO2 leaks through non-fractured caprocks will be minor and will not compromise the storage capacity at CO2 injection sites. The “sealing number” and the “stability number” combine the initial fluid pressure, the buoyant pressure caused by the CO2 plume, the capillary breakthrough pressure of the caprock, and the stress conditions at the reservoir depth; these two numbers provide a rapid assessment of potential storage sites. Unexpected CO2 migration patterns emerge due to the inherent spatial variability and structural discontinuities in geological formations; sites with redundant seal layers should be sought for the safe and long-term storage of CO2.en
dc.description.sponsorshipThis research was performed at the Georgia Institute of Technology with support from the U.S. Department of Energy (DOE) under grant number DE-FE0001826. Complimentary work at The University of Texas at Austin was supported as part of the Center for Frontiers of Subsurface Energy Security (CFSES) funded by the U. S. Department of Energy under Award # DE-SC0001114. Additional support was provided by the The Goizueta Foundation and the KAUST Endowment. Any opinions, findings, conclusions, or recommendations expressed herein are those of the authors and do not necessarily reflect the views of funding organizations.en
dc.publisherElsevier BVen
dc.relation.urlhttp://www.sciencedirect.com/science/article/pii/S1750583617305601en
dc.rightsUnder a Creative Commons license http://creativecommons.org/licenses/by-nc-nd/4.0/en
dc.subjectPercolationen
dc.subjectDrainageen
dc.subjectNon-miscible fluid displacementen
dc.subjectSealing capacityen
dc.subjectCCSen
dc.subjectRelative permeabilityen
dc.titleCO 2 breakthrough—Caprock sealing efficiency and integrity for carbon geological storageen
dc.typeArticleen
dc.contributor.departmentEarth Science and Engineering Programen
dc.identifier.journalInternational Journal of Greenhouse Gas Controlen
dc.eprint.versionPublisher's Version/PDFen
dc.contributor.institutionDepartment of Petroleum and Geosystems Engineering, The University of Texas at Austin, Austin, TX, USAen
kaust.authorSantamarina, Carlosen
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