Development and characterization of a geostatic model for monitoring shallow CO2 injection

Jessica M. Dongas, Donald C. Lawton

A 25 sq. km static geomodel was updated for shallow injection into the 7 m thick Belly River Fm. at 295 m depth in Newell County, AB. Effective porosity and permeability were calibrated to six core lab analyses. A P10-50-90 framework was run to give conservative, typical, and optimistic scenarios of the reservoir’s storage capacity. The regressional shoreline sandstone interval remains consistent across the study area giving a mean effective porosity of 11% and permeability of 0.57 mD. Dynamic simulation was completed on the P10-50-90 static cases for multiple injection scenarios, totaling 5000 t/CO₂ after a 5-year period. No significant variations existed in the results between the three static cases. The evolution of the CO₂ plume was observed at 1-year during injection and 5-years during injection, as well as the 1-year and 10-year mark for the post-injection period. The final 10-year post-injection result simulated a laterally extensive plume, expanding to 350 m in length and 20 m of vertical migration above the BRS Formation. The target interval proves as an ideal reservoir, and the seal interval demonstrates containment over a 10-year post-injection period. Uncertainties remain in the static and dynamic realm, and include reservoir, fracture, and capillary pressure, kV/kH ratio, and the relative kCO₂-H2O. Further work is being completed on a 1 km x 1 km layer cake case, and will be used as documentation as a step towards obtaining the injection license as part of Directive 051 from the Alberta Energy Regulator.