Leonardo Guimarães

Universidade Federal de Pernambuco

Geomechanics of geological CO₂ storage: from pore-scale processes to reservoir response and monitoring

Geological CO₂ storage can involve highly contrasting geological settings, where differences in petrophysical, geomechanical, and geochemical properties control the dominant trapping mechanisms and require characterization and modeling strategies tailored to each storage system. The CO2GEOMEC project investigates two distinct storage candidates: a depleted sandstone gas reservoir and a basalt formation, where the relative importance of structural, residual, dissolution, and mineral trapping differs significantly. An integrated workflow combines geological modeling, petrophysical and rock-mechanics characterization, X-ray computed tomography and digital rock analysis, and coupled flow-geomechanical simulations to investigate processes across scales, from pore- and core-scale phenomena to reservoir-scale CO₂ plume evolution and geomechanical response. Particular attention is given to how these predictions can support the design and interpretation of monitoring strategies, including the identification of measurable signatures associated with pressure changes, deformation, damage, and fluid-rock interactions. Complementary insights from seismic monitoring of underground salt caverns illustrate how geomechanical processes and their evolution can be related to field-scale observations. Together, these studies highlight how geological setting, dominant physical mechanisms, and coupled processes determine not only the appropriate modeling approach but also what should be monitored to assess the integrity and long-term performance of geological storage systems.