{"@context":"https://schema.org","@type":"ScholarlyArticle","headline":"Well and Reservoir Surveillance Using Permanent Distributed Fiber Optic Sensing in Offshore Fields: A Literature Review of Actual Applications and Ongoing Research","author":[{"@type":"Person","name":"T. P. Sampaio"},{"@type":"Person","name":"J. S. Baioco"},{"@type":"Person","name":"D. N. de Miranda"},{"@type":"Person","name":"J. L. D. Alves"}],"datePublished":"2025","isPartOf":{"@type":"Periodical","name":"OTC Brasil"},"identifier":"https://doi.org/10.4043/36028-ms","description":"Abstract\n Permanent Distributed Fiber Optic Sensing (DFOS) has proven its effectiveness in the surveillance of onshore wells and reservoirs. However, its application to offshore fields is still challenging, requiring alternative interpretation methods and installation techniques. Keeping track of the latest developments and future trends is crucial when considering this technology in a production development plan.\n This review begins by highlighting the key differences between onshore and offshore installations. In the former, the fiber optic cable is usually installed outside the cement casing string, while in the latter, it is clamped to the tubing inside casing. Distributed Temperature Sensing (DTS) remains a consolidated technology. On the other hand, Distributed Strain Sensing (DSS) has been largely replaced by Distributed Acoustic Sensing (DAS), significantly impacting surveillance objectives. The review also addresses challenges in data processing, transmission, storage, and interpretation, with a particular focus on Artificial Intelligence algorithms. Finally, it discusses recent field applications and research conducted by universities and companies.\n The installation of fiber optic cables clamped to the tubing reduces sensitivity to strain variations affecting Brillouin scattering. New applications focus on acoustic responses (Rayleigh scattering), directing analysis towards flow behavior inside the tubing, well leakage, and seismic activity. DAS is emerging as the mainstream technology, though its full potential remains unknown. Numerous companies and universities are conducting experimental flow loop studies to investigate what kind of information can be extracted and support equipment specifications and software development. Offshore wells with wet completion require constructing wet connectors to link the cable through the wet Xmas tree and packers. The initial challenge of accessing the upper completion has been overcome enabling successful vertical seismic profile applications. Some companies claim readiness for full-well installations, but literature still lacks actual field results. As DAS generates large volumes of data, there is an important discussion related to the infrastructure (processing, transmission and storage) and the interpretation of data, taking advantage of recent discoveries in the areas of Big Data and Artificial Intelligence.\n This paper investigates the state-of-the-art of Distributed Fiber Optic Sensing technologies applied to the surveillance of offshore wells and reservoirs. It highlights reported challenges and their solutions, thus contributing to align expectations for the near future, based on recent advancements.","url":"https://innscience.ca/en/community/literature/b60e36ae-2fad-4f16-a887-ca5a3ca514c3"}