Objective and hypothesis
CO2 injection in the subsurface can experience intermittent behaviour during the well start-up/shut-in, due to fluctuations in CO2 supply, or due to undesired events. The aim of the project is to tailor a numerical simulation model which will consider single- and multiphase mixtures of CO2 and CO2-rich mixtures in well configurations, including friction and heat transfer. To account for the induced thermal stresses in the cement and the reservoir, the model will be coupled to geomechanical simulators.

Approach
The first key milestone is to deliver a first version of a standalone software tool. This will allow for offline forecasts of the anticipated pressure and temperature profiles along the well, and the associated thermal stresses in the near-wellbore area. Based on iterations between the project team, the simulator will be loosely coupled with a geomechanical simulator. The planned functionality will include elaborate formulation of the geomechanical simulator, results of the calibration on the field data from Stenlille, and a GUI/web interface. Ultimately, the project will provide an assessment of the impact of thermal stresses on wellbore integrity, near- wellbore stability, and reservoir and caprock behaviour.

Expected impact/output
The project is addressing one of the key challenges of the CCUS Roadmap by INNO-CCUS, namely the maturation and de-risking of large potential storage sites. Choosing the right design of a well is key to mitigating some of the risks concerning well integrity. To be able to do this, it is necessary to know the environment around the well in detail. The results of this project are, therefore, crucial in the preparation for a CO2-pilot in Stenlille, which has the potential to accelerate the implementation of full-scale CCS in Denmark. The methods and tools developed in this project can be generalised to usage for other storage sites. Therefore, this project has the potential to significantly improve the economic and societal benefits of storage.

Learn more: https://thermoco2well.dk/