Hypergravity experiments on meter-scale porous media flow for geological carbon sequestration

Reducing atmospheric CO₂, the main driver of global warming, is essential for climate sustainability. Geological storage offers a promising solution for large-scale, long-term sequestration; however, challenges remain in predicting subsurface CO₂ behavior and tracking its migration underground. Laboratory-scale experiments that replicate subsurface storage conditions provide valuable benchmarks for validating numerical simulations. This study investigated CO₂ migration using a geotechnical centrifuge at 50 G. The setup combined a pH-sensitive solution for visualization and a 12-sensor array for pressure monitoring during injection. Multilevel pressure data and image sequences were analyzed across early, middle, and late stages of the test. The early period was marked by a pressure increase associated with CO₂ entry into the sample. Afterwards, the injection rate was adjusted to 2 ml/min, and a gas cap formed, followed by continuous CO₂ vertical and lateral migration. During the mid-stage (5 ml/min), flank pressure declined by 0.07-0.08 kPa/s, while the drop in the central sensors was approximately 0.11 kPa/s. At a later period (10 ml/min), gravity-driven instabilities developed, followed by a second gas cap, and the pressure beneath seal [Formula: see text] increased from 81 to 108 kPa, followed by a dissolution-induced drop to approximately 92 kPa as the CO₂ plume advanced into fault-bounded zones. Dimensionless numbers were used to assess flow regimes and transport mechanisms, as well as to evaluate model-to-prototype scaling laws across the test periods. These findings demonstrate the potential of centrifuge-based hypergravity experiments for CO₂ sequestration research and provide quantitative datasets for benchmarking and validating numerical simulations.