Geologic Heterogeneity Controls on Trapping and Migration of CO2

When CO2 is injected into sedimentary basins, the fate of the buoyant CO2 will be determined by how it interacts with the underlying geologic heterogeneities. Here we geologically print a cross-bedded pattern using two different bead sizes, and then conduct flow experiments to observe buoyant flow pathways, migration speed, and immobilized volumes. The amount of buoyant phase trapped under the heterogeneities is observed to vary by two orders of magnitude, with the controlling parameter being the size contrast between the coarse and fine grains that make up the structure. The results allow an estimate of heterogeneity trapping, and show how CO2 trapping in aquifers can be experimentally evaluated before injection.

Automated summary

This study explores the fate of buoyant CO2 when injected into sedimentary basins by examining its interactions with underlying geologic heterogeneities. By geologically printing a cross-bedded pattern and conducting flow experiments, the researchers observe the pathways, speed, and volume of the buoyant flow. The results provide insights into estimating heterogeneity trapping and evaluating CO2 trapping in aquifers experimentally prior to injection.