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J.J. Thordsen

Publications and source records attributed to J.J. Thordsen.

4 recordsLinked to original sources
USGS2007

Subsurface monitoring of anthropogenic CO 2 injected in sedimentary basins: Results from the Frio-I brine test, Texas, USA

To investigate the potential for the long-term storage of CO 2 in deep saline aquifers, 1600 t of CO 2 were injected at 1500m depth into a 24-m-thick "C" sandstone of the Frio Formation near Houston, Texas. Fluid samples obtained before CO 2 injection from the injection well and an observation well 30m updip showed a Na-Ca-Cl type brine with ∼93,000 mg/L TDS at saturation with CH 4, but only 0.3% CO 2. Following CO 2 breakthrough, samples showed sharp drops in pH, pronounced increases in alkalinity and Fe, and significant shifts in the isotopic compositions of H 2O, and DIC. These parameters, together with perfluorocarbon tracer gases were used for monitoring migration of injected CO 2 into the overlying Frio "B", a 4-m-thick sandstone, separated from the "C" by ∼15m of shale and siltstone beds. Results from "B" 6 mo after injection show significant CO 2 (2.9% vs. 0.3% CO 2) migration into the "B" sandstone. Results of samples collected 15 mo after injection, however, show no indications of additional CO 2 in the "B" sandstone.

Conference Paper↗
USGS2006

Gas-water-rock interactions in sedimentary basins: CO2 sequestration in the Frio Formation, Texas, USA

To investigate the potential for the geologic storage of CO2 in saline sedimentary aquifers, 1600??ton of CO2 were injected at ???1500 m depth into a 24-m sandstone section of the Frio Formation - a regional reservoir in the US Gulf Coast. Fluid samples obtained from the injection and observation wells before, during and after CO2 injection show a Na-Ca-Cl type brine with 93,000??mg/L TDS and near saturation of CH4 at reservoir conditions. As injected CO2 gas reached the observation well, results showed sharp drops in pH (6.5 to 5.7), pronounced increases in alkalinity (100 to 3000??mg/L as HCO3) and Fe (30 to 1100??mg/L), and significant shifts in the isotopic compositions of H2O and DIC. Geochemical modeling indicates that brine pH would have dropped lower, but for buffering by dissolution of calcite and Fe oxyhydroxides. Post-injection results show the brine gradually returning to its pre-injection composition. ?? 2006 Elsevier B.V. All rights reserved.

Journal of Geochemical Exploration↗
USGS2000

Large-scale hydrothermal fluid discharges in the Norris-Mammoth corridor, Yellowstone National Park, USA

Norris–Mammoth corridor is a complex subsidence structure that extends ∼40 km northward from the 0.6 Ma Yellowstone caldera, and contains many hydrothermal features with high fluid discharges totaling ∼1000 l/s. About 150–250 l/s of hydrothermal water, which attains boiling temperature at surface and 360°C at depth, discharge from the Norris Geyser Basin, adjacent to the caldera. The highest thermal water and gas discharges in the corridor are from Mammoth Hot Springs, where 500–600 l/s thermal water with surface temperatures of up to 73°C and calculated subsurface temperatures of ∼100°C issue from ∼100 hot springs scattered over a score of step-like travertine terraces that range in age from ∼0.4 Ma to recent. All the thermal water is meteoric, likely recharged in the Gallatin Range at 2.5–3.0 km elevations. The isotopic and chemical compositions of thermal waters and solutes can be interpreted to indicate a common magmatic source for heat and volatile solutes located near Norris. However, the chemical and isotopic compositions of gases, especially the 3 He/ 4 He ratios, provide strong evidence for a separate magmatic source for the Mammoth system.

Book↗