Meet Kacey Garber, M.S. of SCS Engineers, on Wednesday, June 14, at her 8:30-10am session of the Carbon Capture and Storage Summit. Kacey will be discussing how Carbon Capture and Storage (CCS) is becoming increasingly attractive due to growing climate change concerns as well as tax incentives related to conducting CO2 capture.
Facilities that capture CO2 may consider storing captured CO2 via geologic sequestration (GS). GS at a given location requires a Class VI Underground Injection Control (UIC) permit for a Class VI UIC well(s) to inject supercritical CO2. These permits require multiphase flow modeling to delineate both the extent of the supercritical CO2 plume and areas that exceed a critical pressure threshold as a result of the injection.
At SCS, numerical modeling is also valuable during project scoping to provide a sense of the total CO2 storage capacity for a given project. CO2 trapping (storage) mechanisms must be considered to determine long-term storage capacity, including structural/stratigraphic, capillary, solution, and mineral trapping (depending on geochemistry).
Solubility trapping appears to be the ultimate trapping mechanism for injected CO2 under most geochemical conditions; therefore, solution storage efficiency will be a key metric for project scoping. Solubility trapping occurs when the CO2 dissolves from its separate, buoyant phase into formation pore water. If the total available pore space for the project and the solubility limit of CO2 can be estimated, then the total solution storage capacity can also be estimated.
Then numerical modeling can be used to estimate design and operational parameters to quickly examine under what conditions the most efficient use of pore space occurs. In Ms. Garber’s example, her team investigated what factors may promote solution storage efficiency using a multiphase flow model. This includes how supercritical CO2 injection rate, duration, and location(s) affect solution storage efficiency. This simplified study concluded that injection rate, duration, and location(s) all affect solution storage efficiency. Project-specific considerations need to be incorporated into the model in order to determine the conditions ideal for maximizing solution storage efficiency.
Additional Information located on the Deep Well Injection and Carbon Sequestration site.