Recovering Aging Risers: Environmentally Responsible Disconnection of the Fluminense FPSO Risers and Umbilicals

Abstract This paper explores the recovery of all risers and umbilicals in the BJSA (Bijupira & Salema) fields as part of the Fluminense FPSO disconnection efforts. It highlights the challenges of handling flexible pipelines that were beyond their design life and recovering them, rather than abandoning them on the seabed, to reduce any environmental impact to marine life on the seabed. Guided by the campaign's mantra, "if you touch it, you recover it," the project navigated a period of high activity in the pipelaying vessels market to secure the right assets for such work. Shell's strategic approach allowed contractors the freedom to propose their own disconnection methods, while Shell delineated the operational requirements. The engagement of a rigid reel lay vessel by Riser removal contractor led to the development of creative solutions to manage high loads whilst maintaining the integrity of such aging risers. The initially chosen method of pulling all risers out was adapted to cutting them at the turret, addressing local vessels, blockage issues and reducing the exposure of critical platform equipment, such as the A&R winch. The swivel turret design of the FPSO Fluminense required station-keeping tugs to maintain the platform's heading during removal operations, adding to the complexity of coordinating offshore efforts. The project was executed with a commitment to preventing the release of hydrocarbons into the atmosphere, ensuring that all operations were conducted in an environmentally responsible manner.