Connectivity Impacts in CCS Simulation Using a High-Resolution Fluvial Model from Triassic Outcrop (TIBEM, Spain)

This study evaluates the impact of sedimentary connectivity on CO₂ injection efficiency using a high-resolution geological model of a meandering fluvial system from the Triassic outcrops of the Iberian Meseta (TIBEM, Spain). Developed under the EU-funded SOSGAS project, the model integrates detailed sedimentological descriptions, digital outcrop models, and petrophysical data from the TAGI Formation (MLN Field, Algeria), a recognized subsurface analogue. The simulation, comprising over 10 million cells, employs compositional flow modeling with realistic facies-dependent petrophysical and capillary properties.

Results demonstrate that facies connectivity plays a critical role in CO2 migration and pressure dynamics. Scenarios with direct channel-to-channel connectivity yielded faster plume arrival times and lower pressure buildup at injector wells, while configurations involving crevasse-splay deposits exhibited delayed plume migration and earlier pressure limits. Despite similar sweep volumes across cases, injectivity and plume timing varied significantly, underscoring the influence of fine-scale heterogeneities on flow performance.

These findings highlight the importance of accurate geological characterization and strategic well placement to optimize CO2 injection in fluvial reservoirs. By quantifying the dynamic behavior of connected versus poorly connected facies, this study provides valuable insights for improving the predictability and efficiency of carbon storage in heterogeneous sedimentary systems.