2015/04/20 by Víctor Vilarrasa, Jesús Carrera · 3 citations
Environmental Science · Earth and Planetary Sciences · Chemistry · #CO2 Sequestration and Geologic Interactions #earthquake and tectonic studies #Geological and Geochemical Analysis #Caprock #Overpressure #Geology #Induced seismicity #Petroleum engineering #Sedimentary rock #Brine #Leak #Petrology #Geotechnical engineering #Geochemistry #Environmental science #Seismology #Chemistry
paper · pdf · doi:10.1073/pnas.1413284112
openalex publication_date 2015/04/20 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/04
Zoback and Gorelick [(2012) Proc Natl Acad Sci USA 109(26):10164-10168] have claimed that geologic carbon storage in deep saline formations is very likely to trigger large induced seismicity, which may damage the caprock and ruin the objective of keeping CO2 stored deep underground. We argue that felt induced earthquakes due to geologic CO2 storage are unlikely because (i) sedimentary formations, which are softer than the crystalline basement, are rarely critically stressed; (ii) the least stable situation occurs at the beginning of injection, which makes it easy to control; (iii) CO2 dissolution into brine may help in reducing overpressure; and (iv) CO2 will not flow across the caprock because of capillarity, but brine will, which will reduce overpressure further. The latter two mechanisms ensure that overpressures caused by CO2 injection will dissipate in a moderate time after injection stops, hindering the occurrence of postinjection induced seismicity. Furthermore, even if microseismicity were induced, CO2 leakage through fault reactivation would be unlikely because the high clay content of caprocks ensures a reduced permeability and increased entry pressure along the localized deformation zone. For these reasons, we contend that properly sited and managed geologic carbon storage in deep saline formations remains a safe option to mitigate anthropogenic climate change.