TY - JOUR

T1 - Impact of Relative Permeability Hysteresis on CO2 Storage in Saline Aquifers

AU - Khoramian, Reza

AU - Salaudeen, Ibraheem

AU - Pourafshary, Peyman

AU - Riazi, Masoud

AU - Kharrat, Riyaz

PY - 2024/11

Y1 - 2024/11

N2 - The urgent challenge of climate change, driven by rising carbon emissions, necessitates innovative strategies for carbon captureand storage (CCS). This study examines the impact of hysteresis in relative permeability on CO2 entrapment efficiency withinsaline aquifers, known for their significant storage capabilities. An aquifer model was analyzed through numerical simulation byvarying hysteresis values from 0.2 to 0.5 to evaluate their impact on CO2 plume behavior, retention during water-alternating-gas(WAG) injection, and plume morphology. The CO2 plume exhibits a funnel-shaped configuration at low hysteresis with a narrow,pointed base, indicating a concentrated upward migration trajectory. In contrast, a hysteresis value of 0.5 results in diminished gasmovement toward the upper aquifer, transforming the plume into a more oval shape. Results from the land trapping model furthersupport our findings, revealing an inverse relationship where increased hysteresis enhances residual CO2 entrapment, reflectedin trapping coefficient values ranging from 0.5 to 4. This underscores the model’s efficacy in verifying gas trapping efficiency andsafety during sequestration. Moreover, increased water flow generates stronger forces, pushing CO2 into narrower pore spaces,where it becomes trapped. Our findings indicate that increased hysteresis enhances CO2 retention by limiting vertical migrationand significantly influences plume geometry, promoting stable and predictable distribution patterns. At higher hysteresis values,CO2 migration is significantly restricted, resulting in near-complete immobilization of the injected gas. This research highlightshysteresis’s critical role in refining injection methodologies and enhancing plume stability for long-term CO2 storage.

AB - The urgent challenge of climate change, driven by rising carbon emissions, necessitates innovative strategies for carbon captureand storage (CCS). This study examines the impact of hysteresis in relative permeability on CO2 entrapment efficiency withinsaline aquifers, known for their significant storage capabilities. An aquifer model was analyzed through numerical simulation byvarying hysteresis values from 0.2 to 0.5 to evaluate their impact on CO2 plume behavior, retention during water-alternating-gas(WAG) injection, and plume morphology. The CO2 plume exhibits a funnel-shaped configuration at low hysteresis with a narrow,pointed base, indicating a concentrated upward migration trajectory. In contrast, a hysteresis value of 0.5 results in diminished gasmovement toward the upper aquifer, transforming the plume into a more oval shape. Results from the land trapping model furthersupport our findings, revealing an inverse relationship where increased hysteresis enhances residual CO2 entrapment, reflectedin trapping coefficient values ranging from 0.5 to 4. This underscores the model’s efficacy in verifying gas trapping efficiency andsafety during sequestration. Moreover, increased water flow generates stronger forces, pushing CO2 into narrower pore spaces,where it becomes trapped. Our findings indicate that increased hysteresis enhances CO2 retention by limiting vertical migrationand significantly influences plume geometry, promoting stable and predictable distribution patterns. At higher hysteresis values,CO2 migration is significantly restricted, resulting in near-complete immobilization of the injected gas. This research highlightshysteresis’s critical role in refining injection methodologies and enhancing plume stability for long-term CO2 storage.

KW - carbon sequestration

KW - CO2 storage | hysteresis

KW - relative permeability

KW - saline aquifers

KW - WAG injection

M3 - Article

JO - Greenhouse Gases: Science and Technology

JF - Greenhouse Gases: Science and Technology

SN - 2152-3878

ER -