RE-USING EXISTING WELLS FOR CO₂ STORAGE OPERATIONS

This project deals with the question of how to evaluate and assess existing well infrastructure to potentially re-use it for CO₂ storage operations. The consortium is made up of a mixture of research institutions, operators, and regulatory authorities, from a total of 6 countries.

Summary

Existing oil and gas industry installations which cover large parts of the potential CCS chain are already in place, and an increasing number of reservoirs have come to the end of their production lifetime and are earmarked as major targets for initiating large-scale CCUS operations. The existing wells in these assets present both opportunity and challenges. Substantial savings could be realized by re-using these wells as CO₂ injectors, monitoring wells, or for water production (pressure management). On the other hand, the existing well infrastructure poses a risk as a potential CO₂ or brine leakage pathway. In this proposal, we take a fresh look at this problem and provide a novel solution. The re-use of wells is the inverse of the problem of identifying defective wells. The process of certifying well integrity can also be used to identify wells suitable for continued use in a CO₂-rich environment. We develop a qualification process that will simultaneously save CO₂ storage projects money and time by identifying existing infrastructure that is safe to re-use, while determining which wells must be remediated to ensure long-term storage.

Re-use can benefit projects in all geological settings but may be particularly crucial for off-shore environments, such as the North Sea or the Gulf of Mexico, where well development costs could otherwise be prohibitive. Developing a procedure and tools for evaluating the re-use potential of existing hydrocarbon fields and wells will require a dedicated investigation encompassing the interrelated technical, environmental, economic and social aspects. Currently no such publicly available tool exists. For this project, we conduct the necessary research to develop a dedicated well-screening tool for Re-using EXisting Wells for CO₂ storage operations (REX-CO₂).