CO2 Sequestration and Aquifer Characterization - PDF Print Version
Head Map Showing Brine Movement
in an Aquifer
Use of a Vector Model to Calculate Migration and Residence Times
Flow Capacity and Permeability can be Determined by Matching Pressure History with a Composite Flow Model
Injectivity is the Negative of Deliverability Shown in this Figure
Large volume (megatonne) carbon capture in saline aquifers is a relatively new field of investigation for Canadian Discovery Ltd. Our reservoir characterization and hydrogeological expertise has placed us at the front of this emergent field.
Key hydrogeological concepts used to assess the suitability of saline aquifers for carbon capture are:
- Flow Field Analysis: Defining the force of brine movement in the aquifer.
- Vector Modelling: Assessing the effect of flowing brine on the injected CO2 mass, determining the regional migration paths (streamlines) and defining potential structural and stratigraphic traps.
- Residence Time Assessment: Combining aquifer flow capacity with the magnitude of the migrating CO2 mass to determine flow velocity and migration and residence times.
Aquifer characterization is conducted to assess suitability for
CO2 injection. Typical considerations would include:
- Flow Capacity: State of the art software is used to analyze flow tests, and to determine the permeability, thickness and shape of the aquifer. Flow capacity is also assessed using calibrated log and core data.
- Injectivity: The ability of an aquifer to accept injected CO2 is governed by the flow capacity and the fracture stress limits of the caprock and reservoir.
- Stress Analysis: The fracture limits for the aquifer and caprock are determined and injection rates would have to be tailored so that reservoir pressure will always be less than these.