investigating the ground deformation during and after co2 sequestration in deep saline aquifers

Co2 injection in saline aquifers is a crucial method for carbon sequestration, reducing atmospheric co2 levels and mitigating climate change. saline aquifers, due to their large capacity and widespread availability, serve as effective storage sites for co2, helping to isolate it long-term and prevent its release back into the atmosphere. this study investigates the uplift of the top surface of a deep saline aquifer due to co2 injection, using the finite element numerical approach. the density and viscosity of the injected supercritical co2 were considered as functions of temperature and pressure, while the density and viscosity of saline water were similarly modeled as temperature- and pressure-dependent. geothermal temperature variations were also incorporated into the model. additionally, the effects of halting injection after a certain period and the subsequent spread of injected co2 in the aquifer, driven by capillary and gravitational forces, were examined in relation to the displacements. both horizontal and vertical well configurations were studied. the modeling results indicated that with a vertical well, the co2 plume extended to higher levels and farther distances from the injection point compared to a horizontal well, resulting in greater surface uplift with the horizontal well configuration. the impact of permeability anisotropy was also analyzed, revealing that when horizontal permeability is ten times greater than vertical permeability, the co2 plume spreads horizontally, substantially reducing the aquifer surface uplift.

investigating the ground deformation during and after co2 sequestration in deep saline aquifers

co2 injection in saline aquifers is a crucial method for carbon sequestration, reducing atmospheric co2 levels and mitigating climate change. saline aquifers, due to their large capacity and widespread availability, serve as effective storage sites for co2, helping to isolate it long-term and prevent its release back into the atmosphere. this study investigates the uplift of the top surface of a deep saline aquifer due to co2 injection, using the finite element numerical approach. the density and viscosity of the injected supercritical co2 were considered as functions of temperature and pressure, while the density and viscosity of saline water were similarly modeled as temperature- and pressure-dependent. geothermal temperature variations were also incorporated into the model. additionally, the effects of halting injection after a certain period and the subsequent spread of injected co2 in the aquifer, driven by capillary and gravitational forces, were examined in relation to the displacements. both horizontal and vertical well configurations were studied. the modeling results indicated that with a vertical well, the co2 plume extended to higher levels and farther distances from the injection point compared to a horizontal well, resulting in greater surface uplift with the horizontal well configuration. the impact of permeability anisotropy was also analyzed, revealing that when horizontal permeability is ten times greater than vertical permeability, the co2 plume spreads horizontally, substantially reducing the aquifer surface uplift.