FAR-FIELD IMPACTS OF CARBON DIOXIDE SEQUESTRATION IN DEADWOOD-BLACK ISLAND SALINE AQUIFERS (A SENSITIVITY ANALYSIS ON PRESSURE PERTURBATION AND BRINE MIGRATION)

Geologic carbon sequestration method is used to store and secure carbon dioxide (CO2) in deep subsurface formations and prevents CO2 from being released into the atmosphere. Deep saline aquifers are widespread and have large storage capacities to store carbon dioxide. A major concern with carbon dioxide sequestration is the CO2 leakage through the overlying formations and shallow fresh water aquifers as well as brine displacement and pressure build up. This built up pressure may displace the formation water and push it away from the injection well toward up dip fresh groundwater aquifers.

The study area in this research is located in southeast Saskatchewan and geologically is within the Williston Basin. In this research, far-field impacts of CO2 injection in Deadwood-Black island sandstone formations was simulated by using TOUGH2/ECO2M simulator which is a multiphase flow simulation code. The main purpose of this study is to determine the effect of CO2 injection on brine displacement and pressure perturbation within the reservoir formations as well as any possible environmental impacts from the injection process on shallow fresh water aquifers. In addition, the impacts of different parameters such as grid resolution, boundary conditions, and model domains were also evaluated as sensitivity analysis to come up with the appropriate approach to simulate this process. The accuracy of simulation results, then, will be evaluated based on the field measurements from the observation well located 150 m away from the injector as well as surface soil and water samplings.