The overall aim of this work package is to gain a better insight into what conditions lead to good wellbore integrity, which basically means high sealing capacity and no leakage
Near-well sealing integrity
Participants: BRGM, EIFER, IGG-CNR, PHIMECA, TNO, SWISSTOPO
Active or abandoned wells constitute direct connections and preferential paths between the surface and the storage reservoir through which CO2 might escape driven by buoyancy forces. The long-term sealing
integrity of such objects is of first importance, especially the pathways potentially existing via altered well compartments (formation caprock, cement sheet and casing) or along deficient bounding interfaces between
The goal is to combine field and laboratory experiments, and modelling efforts in order to evaluate the conditions of the near-well confinement on a long time scale. Work package 5 is focused on well integrity and, more specifically, the evolution of the well sealing properties when in contact with CO2. The final aim is gain a better insight into what conditions provide good well integrity and, more particularly, to:
- evaluate the chemical interactions between CO2 (and formation fluid) and the well environment (close formation, cement, casing);
- assess the consequences of these interactions on the effective hydraulic and transport properties of the well environment.
- Task 5.1 Field experiment in the Mont Terri Underground Rock Laboratory (URL) – CO2 stream in contact with wellbore compartments and interfaces. This intermediate scale between classical lab experiments and field operations will allow both to retrieve the essential well features (caprock/cement/casing/cement compartments) and to control and follow closely their evolution when in contact with CO2.click on image to enlarge
- Task 5.2 Well compartments fluid-rock interactions assessment. Dedicated to the geochemical interactions occurring between CO2 rich fluids, well features and caprock, both at the laboratory scale and at the scale of the URL experiment. The laboratory experiments in similar conditions that the URL one will allow a better understanding of the URL experiment. Modelling effort will be done to predict and calibrate the results of the URL experiment.
- Task 5.3 Leakage pathways evaluation. Dedicated to the characterization of the hydraulic properties of the well environment; the evolution of such properties will be evaluated through the continuous monitoring of the URL experiment and associated modelling. Sampling of the well features at the end of the experiment an understanding of the flow pathways.
- Task 5.4 Uncertainty assessment and integration. Focused on the understanding of the consequences of the uncertainties associated to the geochemical and transport modeling stages and their management
Dernière mise à jour le 18.08.2015