Gas-water-rock interactions in Frio Formation following CO2 injection: Implications for the storage of greenhouse gases in sedimentary basins

Abstract

Research Article| July 01, 2006 Gas-water-rock interactions in Frio Formation following CO2 injection: Implications for the storage of greenhouse gases in sedimentary basins Y.K. Kharaka; Y.K. Kharaka 1U.S. Geological Survey, MS/427, 345 Middlefield Rd., Menlo Park, California 94025, USA Search for other works by this author on: GSW Google Scholar D.R. Cole; D.R. Cole 2Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA Search for other works by this author on: GSW Google Scholar S.D. Hovorka; S.D. Hovorka 3Bureau of Economic Geology, University of Texas, Austin, Texas 78713, USA Search for other works by this author on: GSW Google Scholar W.D. Gunter; W.D. Gunter 4Alberta Research Council, Edmonton, Alberta T6N 1E4, Canada Search for other works by this author on: GSW Google Scholar K.G. Knauss; K.G. Knauss 5Lawrence Livermore National Laboratory, Livermore, California 94550, USA Search for other works by this author on: GSW Google Scholar B.M. Freifeld B.M. Freifeld 6Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA Search for other works by this author on: GSW Google Scholar Author and Article Information Y.K. Kharaka 1U.S. Geological Survey, MS/427, 345 Middlefield Rd., Menlo Park, California 94025, USA D.R. Cole 2Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA S.D. Hovorka 3Bureau of Economic Geology, University of Texas, Austin, Texas 78713, USA W.D. Gunter 4Alberta Research Council, Edmonton, Alberta T6N 1E4, Canada K.G. Knauss 5Lawrence Livermore National Laboratory, Livermore, California 94550, USA B.M. Freifeld 6Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA Publisher: Geological Society of America Received: 14 Nov 2005 Revision Received: 24 Feb 2006 Accepted: 01 Mar 2006 First Online: 09 Mar 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 The Geological Society of America, Inc. Geology (2006) 34 (7): 577–580. https://doi.org/10.1130/G22357.1 Article history Received: 14 Nov 2005 Revision Received: 24 Feb 2006 Accepted: 01 Mar 2006 First Online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation Y.K. Kharaka, D.R. Cole, S.D. Hovorka, W.D. Gunter, K.G. Knauss, B.M. Freifeld; Gas-water-rock interactions in Frio Formation following CO2 injection: Implications for the storage of greenhouse gases in sedimentary basins. Geology 2006;; 34 (7): 577–580. doi: https://doi.org/10.1130/G22357.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract To investigate the potential for the geologic storage of CO2 in saline sedimentary aquifers, 1600 t of CO2 were injected at 1500 m depth into a 24-m-thick sandstone section of the Frio Formation, a regional brine and oil reservoir in the U.S. Gulf Coast. Fluid samples obtained from the injection and observation wells before CO2 injection showed a Na-Ca-Cl–type brine with 93,000 mg/L total dissolved solids (TDS) at near saturation with CH4 at reservoir conditions. Following CO2 breakthrough, samples showed sharp drops in pH (6.5–5.7), pronounced increases in alkalinity (100–3000 mg/L as HCO3) and Fe (30–1100 mg/L), and significant shifts in the isotopic compositions of H2O, dissolved inorganic carbon (DIC), and CH4. Geochemical modeling indicates that brine pH would have dropped lower but for the buffering by dissolution of carbonate and iron oxyhydroxides. This rapid dissolution of carbonate and other minerals could ultimately create pathways in the rock seals or well cements for CO2 and brine leakage. Dissolution of minerals, especially iron oxyhydroxides, could mobilize toxic trace metals and, where residual oil or suitable organics are present, the injected CO2 could also mobilize toxic organic compounds. Environmental impacts could be major if large brine volumes with mobilized toxic metals and organics migrated into potable groundwater. The δ18O values for brine and CO2 samples indicate that supercritical CO2 comprises ∼50% of pore-fluid volume ∼6 mo after the end of injection. Postinjection sampling, coupled with geochemical modeling, indicates that the brine gradually will return to its preinjection composition. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.