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Geophysical early warning of salt precipitation during geological carbon sequestration.
- Source :
-
Scientific reports [Sci Rep] 2020 Oct 05; Vol. 10 (1), pp. 16472. Date of Electronic Publication: 2020 Oct 05. - Publication Year :
- 2020
-
Abstract
- Sequestration of industrial carbon dioxide (CO <subscript>2</subscript> ) in deep geological saline aquifers is needed to mitigate global greenhouse gas emissions; monitoring the mechanical integrity of reservoir formations is essential for effective and safe operations. Clogging of fluid transport pathways in rocks from CO <subscript>2</subscript> -induced salt precipitation reduces injectivity and potentially compromises the reservoir storage integrity through pore fluid pressure build-up. Here, we show that early warning of salt precipitation can be achieved through geophysical remote sensing. From elastic P- and S-wave velocity and electrical resistivity monitoring during controlled laboratory CO <subscript>2</subscript> injection experiments into brine-saturated quartz-sandstone of high porosity (29%) and permeability (1660 mD), and X-ray CT imaging of pore-scale salt precipitation, we were able to observe, for the first time, how CO <subscript>2</subscript> -induced salt precipitation leads to detectable geophysical signatures. We inferred salt-induced rock changes from (i) strain changes, (ii) a permanent ~ 1.5% decrease in wave velocities, linking the geophysical signatures to salt volume fraction through geophysical models, and (iii) increases of porosity (by ~ 6%) and permeability (~ 7%). Despite over 10% salt saturation, no clogging effects were observed, which suggests salt precipitation could extend to large sub-surface regions without loss of CO <subscript>2</subscript> injectivity into high porosity and permeability saline sandstone aquifers.
Details
- Language :
- English
- ISSN :
- 2045-2322
- Volume :
- 10
- Issue :
- 1
- Database :
- MEDLINE
- Journal :
- Scientific reports
- Publication Type :
- Academic Journal
- Accession number :
- 33020529
- Full Text :
- https://doi.org/10.1038/s41598-020-73091-3