2H Offshore is responsible for many of the hybrid riser systems conceived to date. Designing for different environments and operators has taught us to identify and understand the numerous intricacies and challenges posed by individual projects, meaning that we can reuse the best features to create the most suitable hybrid system for new developments.
Our experience with freestanding hybrid risers (FSHRs) began with the design of the Girassol hybrid riser bundle arrangement for Total. This was the first tow-out hybrid riser. Following that, we also designed the single line hybrid riser or Single Line Offset Riser (SLOR™) used on Exxon’s Kizomba A and the more complex pipe-in-pipe or Concentric Offset Risers (COR) used on Kizomba B. All subsequent hybrid riser designs have largely followed the design approach of these pioneering riser systems. More recently, we have been involved in the detailed design of the innovative buoyancy sustained riser system (BSR) for Petrobras, where a submerged tethered buoy provides support for up to 24 hybrid lines.
- Riser configuration and sizing
- Buoyancy tank structural and ballast system engineering
- Global and local strength and fatigue assessment
- Specifications for structures, connectors, rigid and flexible riser section
- Upper and lower assembly detailed engineering
- Riser base spool configuration definition and detailed design
- Fabrication and testing support and witnessing
- Procurement and fabrication management
- Transportation and installation engineering and analysis
- Integrity management, monitoring and failure investigation
- Cost and risk assessment
- Woodside – Relocatable DP FLNG riser system assessment
- Total – Kaombo detailed engineering of 18 freestanding hybrid risers
- Petrobras – Buoy supported freestanding hybrid risers for Lula Extremo Sul, Lula Norte, Cascade and P-52
- BP – PSVM single line hybrid riser detailed engineering
- Exxon – Kizomba A and B freestanding single line and pipe in pipe risers
- BP – GoM containment riser system detailed engineering, delivery and installation
- Total – Girassol hybrid riser bundle concept engineering and detailed analysis
Did you know?
The earliest hybrid riser system was installed by Placid in Green Canyon 29 in 1988. The same riser was retrieved and later installed by Ensearch in Garden Banks in 1994. This riser system formed the basis of the hybrid riser bundle arrangement developed by 2H for the Girassol project, installed offshore Angola in 2001. 2H received a technology achievement award from BP for our work on developing this system.