TY - THES

T1 - CO2 Storage in Supercritical Geothermal Systems

AU - Übelleitner, Jan

N1 - no embargo

PY - 2024

Y1 - 2024

N2 - The increasing concentration of atmospheric carbon dioxide (CO2) poses a significant threat to global climate stability, necessitating innovative solutions for effective long-term carbon sequestration. CO2 storage in supercritical geothermal reservoirs is a promising solution for this problem, utilizing the unique density properties of CO2 and water under supercritical conditions. Above the critical temperature and pressure of water, supercritical CO2 has a higher density, largely mitigating concerns about leakage. This is of particular interest in volcanically active areas, where geothermal potential and carbon sequestration may be used in tandem to generate renewable energy while simultaneously reducing atmospheric CO2 levels. Previous studies have demonstrated the potential for CO2 to sink in these supercritical environments at constant temperatures. However, the effects of temperature gradients on CO2 migration patterns have not been thoroughly analyzed. This leaves a gap in the research, as reservoirs encountered in real life do not exhibit a constant temperature throughout. To address this gap, this work investigates CO2 injection behavior through a series of 2D simulations of varying permeability and a realistic temperature distribution. The temperature distribution is created by placing a heat source, representing a magmatic intrusion, in a part of the reservoir. By calculating gravity numbers and plotting saturation profiles, the study evaluates the balance between viscous and buoyant forces governing CO2 plume patterns, revealing distinct migration behaviors, especially at high permeabilities. These in particular showed promising results in the previous studies. The results include unexpected CO2 movement patterns due to convection and provide insights into bulk fluid flows and viscosity profiles over time. These results highlight the importance of detailed reservoir evaluation to ensure safe and effective CO2 storage, and contribute valuable knowledge to the field of carbon sequestration in geothermal reservoirs.

AB - The increasing concentration of atmospheric carbon dioxide (CO2) poses a significant threat to global climate stability, necessitating innovative solutions for effective long-term carbon sequestration. CO2 storage in supercritical geothermal reservoirs is a promising solution for this problem, utilizing the unique density properties of CO2 and water under supercritical conditions. Above the critical temperature and pressure of water, supercritical CO2 has a higher density, largely mitigating concerns about leakage. This is of particular interest in volcanically active areas, where geothermal potential and carbon sequestration may be used in tandem to generate renewable energy while simultaneously reducing atmospheric CO2 levels. Previous studies have demonstrated the potential for CO2 to sink in these supercritical environments at constant temperatures. However, the effects of temperature gradients on CO2 migration patterns have not been thoroughly analyzed. This leaves a gap in the research, as reservoirs encountered in real life do not exhibit a constant temperature throughout. To address this gap, this work investigates CO2 injection behavior through a series of 2D simulations of varying permeability and a realistic temperature distribution. The temperature distribution is created by placing a heat source, representing a magmatic intrusion, in a part of the reservoir. By calculating gravity numbers and plotting saturation profiles, the study evaluates the balance between viscous and buoyant forces governing CO2 plume patterns, revealing distinct migration behaviors, especially at high permeabilities. These in particular showed promising results in the previous studies. The results include unexpected CO2 movement patterns due to convection and provide insights into bulk fluid flows and viscosity profiles over time. These results highlight the importance of detailed reservoir evaluation to ensure safe and effective CO2 storage, and contribute valuable knowledge to the field of carbon sequestration in geothermal reservoirs.

KW - CO2

KW - Speicherung

KW - Geothermal

KW - Überkritisch

KW - CO2

KW - Storage

KW - Geothermal

KW - Supercritical

U2 - 10.34901/mul.pub.2025.016

DO - 10.34901/mul.pub.2025.016

M3 - Master's Thesis

ER -