Riser Concepts for High Motion Vessels in Ultradeep Water

Power, T.L., Head, W., Royer, B.


The paper addresses early work executed during the research study for RPSEA project 10121-4401-01 Ultra-Deepwater Riser Concepts for High Motion Vessels. The steel catenary riser is the simplest riser configuration but has limitations when attached to a high-motion vessel, such as a conventional semi-submersible or a ship-shape floating, production, storage, and offloading vessel (FPSO), in water depths approaching 10,000 feet. Further challenges are posed by the high-pressure, high-temperature reservoirs that can be encountered at these water depths. Alternate riser arrangements to meet the demands of both ultra-deepwater and high motion vessels are investigated. Production is assumed to be high pressure (20,000 psi SITP), high temperature (350°F), and sour. Configurations include wave shapes and other methods to reduce the coupling between vessel motion and the fatigue-critical riser touchdown zone. The work described in this paper is primarily concerned with static configuration and vessel payload considerations of the various riser material/configuration options.

Power, T.L., Head, W., Royer, B. “Riser Concepts for High Motion Vessels in Ultradeep Water,” Proceedings of Offshore Technology Conference, Houston, Texas,  May 6–9, 2013.