WellFate – Understanding Fluid Migration Processes at Offshore
Imagine a world where we can safely store carbon emissions or hydrogen in wells after they’ve served their primary purpose. This is the vision behind the WELLFATE project that seeks to shed light on the complex subsurface processes around boreholes to optimize well-decommissioning protocols and ensure their environmental safety.
Understanding fluid migration processes at offshore well sites and rating the risk of leakage based on well design, decommissioning methods, geology, and subsurface conditions.
The Norwegian Continental Shelf is a vast petroleum province that is perforated by nearly 7,000 wells, which have either been plugged and abandoned or are heading for decommissioning in the next decades. The integrity of these wells has been recently questioned, with suspected methane leakage raising serious implications for the environment and climate. However, the current paucity of direct observations and samples at leaky wells limits our confidence to constrain emission fluxes, fingerprint the origin of the methane and ultimately prevent us to correlate geology and well design to a risk of leakage. The aim of the project WELLFATE is to understand the processes of fluid migration near wells, which is crucial to achieve sustainability of marine resources from the Norwegian continental shelf (NCS), particularly when planning to repurpose depleted reservoirs for carbon storage to reduce global emissions. Our multidisciplinary approach is to characterize leaky well sites by integrating direct seafloor observations, geophysical, geochemical, and geological data with well configuration and P&A data. In addition, we will deploy a seabed observatory to monitor emission rates and variations over a full year. This strategy will allow us to confidently interpret fluid migration pathways, define the origin of the fluids, date the onset of leakage, and relate the system’s dynamics with well configuration and geology to identify critical wells and predict possible locations of leakage. Ultimately, the project results can be used to develop guidelines and best practices to optimize well-decommissioning protocols and/or implement early drilling strategies to prevent lateral fracturing in sensitive sedimentary units and propose possible solutions to mitigate already leaking P&A wells.
WELLFATE is part of the solution for the sustainable management of the worlds’ oceans, with positive impact on the environment, society, and industry. It will provide scientifically based input for guidelines and best practices to optimize well decommissioning protocols and possible solutions to improve already leaking plugged wells
University of Tromsø, University of Stavanger, University of Oslo, Equinor, Vår Energi
Collaborators and observers: Geomar (Germany), Technical University of Denmark (DTU), Norwegian Offshore Directorate, Norwegian Ocean Industry Authority