Carbon capture and storage (CCS) is a key technology to enable Canada to meet its 2030 GHG emissions reductions targets. A key big research question is to assess the capacity of subsurface formations to receive and safely store CO2 over long periods of time, to support the regulatory framework of CCS and to alleviate any public concerns about this technology. To address this question we will undertake collaborative research into modeling multiphase flow, heat transport and geomechanical changes that may occur due to CO2 sequestration. The injected CO2 will be at different temperature than the target formation, in liquid or gas state at different depths and less dense than the aquifer water so that the injected CO2 may migrate due to density and pressure gradients. Wellbore integrity can also be affected by temperature fluctuations within the near-field environment of the well. It will vary with the heat transferred from the fluids flowing in the well. The heat properties of the materials within and around the wellbore are complicated by:
- Thermally driven advection of the fluids around the wellbore, and
- Complicated pressure/ temperature/ enthalpy relations and phase state of the injected fluid.
In water injection, the first process will be important; in CO2 injection, both will be. The thermal data being collected at the Aquistore site (Dr. Chalaturnyk) over the last 24 months and the impending subsurface data collected from CO2 injection at the CaMI site (Dr. Lawton) will provide unparalleled field data for this research study. The collaborative research project presents the opportunity both to validate an existing physical model with field data, and to better constrain heat transfer predictions between the wellbore and the near well environment and improve our understanding of various thermal issues related to CO2 sequestration, including injectivity index and downhole injection temperature, phase behaviour, density mixing, changes in formation porosity and permeability, risk of leakage and ground subsurface deformations
To advance our understanding of containment, conformance and injectivity processes associated with the geological storage of CO2, this research project will take leverage access to invaluable field performance data collected at these two Canadian projects to study the following:
- Experimental studies to advance our understanding of potential subsurface issues (i.e. containment, conformance) related to cold CO2 injection.