Deepwater Hybrid Riser Systems

The future "Asia" deep water field developments will require new riser technologies to meet with the economical & operational demands, while ensuring safe and environmentally responsible applications. The development of deep water oil & gas fields have motivated the need to develop new riser concepts (i.e. hybrid risers) in complement to the existing top tensioned risers, flexible or steel catenary risers. The paper starts with a brief historical review of the "popular" Free Standing Hybrid Risers (FSHR) and the bundle Riser Towers (RT). Both riser concepts have been successfully installed in recent years; mainly in Angola, Nigeria, Brazil and Gulf of Mexico. The Llatest evolution on hybrid riser designs will be also presented such as the Buoy Support Risers (BSR, Brazil), the Free Standing Flexible Riser (FSFR) and the Multi-Line Free Standing Risers (ML-FSR); the latter being a riser bundle to be fully assembled & installed offshore. Application: The paper will include the riser design methodology with references to industry codes & standards, recommended practices, etc. Typical functional loads and environmental load case matrix will be presented. Outline installation procedure of each riser system, including typical marine vessel spreads will be presented, e.g. for "Asia" installation fleet benchmarking and (future) availability review. The Specific aspects of each technology readiness for "Asia" applications will be discussed, including the pros and cons of each system will be discussed. Results, Observation, Conclusions: The riser systems shall be designed for Asia "cyclone" conditions (e.g. 10 000 years wave return period) for both short term strength robustness verification and long term fatigue analyses. Typical functional loads and environmental load case matrix will be presented. Significance of Subject Matter: Outline installation procedure of each riser system, including typical marine vessel spreads will be presented, e.g. for "Asia" installation fleet benchmarking and (future) availability review. The future "Asia" deep water field developments will require new riser technologies to meet with the economical & operational demands, while ensuring safe and environmentally responsible applications.