THERMESI – Thermal Effects on Seal Integrity

Background
Geological sequestration of CO₂ is crucial for a low-carbon future, requiring the storage of over 90 gigatonnes of CO₂ by 2050 to meet climate targets. This involves capturing and storing hundreds of millions of tonnes of CO₂ annually at multiple sites. Effective storage depends on the integrity and capacity of geological formations, which must be monitored and managed to prevent leakage and ensure stability of storage complex. The large-scale injection of cold CO₂ will alter the hydraulic, mechanical, and thermal properties of the storage complex, particularly around the injector, posing challenges such as increased pore pressure and thermal stresses. Advanced numerical models are essential to predict and manage these changes, ensuring the safe and efficient storage of CO₂ and that integrity of the seal is maintained.

Goal
The THERMESI project aims to understand the effects of injecting cold CO₂ into hot reservoirs, particularly the risk of caprock failure due to thermal stresses. The project will conduct lab- and full-scale experiments to quantify these stresses and validate mathematical models. Key objectives include designing experiments to study thermal stresses, simulating these experiments to improve confidence in predictive models, and performing detailed modelling of reservoir/caprock interfaces as well as regional-scale modelling to investigate the implications of thermal effects on a storage complex. The findings will be shared through various scientific and technical channels.

Activities
The activities are organized in work packages: WP1 is about data mining and creating a database of seal materials and their pressure and temperature dependencies. WP2 is about thermal stress experiments in both laboratory-scale and full-scale, in a controlled environment, to investigate thermal effects on seal material and the reservoir-seal interface. WP3 is a about numerical modelling and back-calculation of the experiments in WP2. WP4 is numerical regional scale modelling to investigate the implications of thermal effects for geomechanical assessment of safe storage and leakage risk. Finally, WP5 is project coordination and dissemination.