1:1 Scale Wellbore Experiment and Associated Modeling for a Better Understanding of Well Integrity in the Context of CO2 Geological Storage

AbstractIn this study, we present a new experiment for following the evolution of the well integrity over time due to different changes in well conditions (pressure, temperature and fluids in contact with the well) in the context of CO2 geological storage. A small section of a wellbore is reproduced in the Opalinus Clay of the underground rock laboratory of Mont-Terri, Switzerland (caprock-like formation) at scale 1:1. This system has been characterized hydraulically and geochemically during three periods: initial state, after an increase in the well temperature and after replacing the fluid by pore water with dissolved CO2. The characterization of the system includes both performing hydro-tests to quantify the hydraulic properties of the well and their evolution over time, and sampling the fluids to analyze the geochemical composition and changes. The results presented in this study confirm the ability of the chosen design to estimate the evolution of the well integrity over time