Sub-Surface Buoy Hybrid Riser System for Deepwater Application

A Sub-Surface buoy hybrid riser system is considered as a solution for deepwater export systems. Besides the in place static and dynamic loads, the installation operation was analyzed. The development includes the reduced model tests in a (so far) unique Deep Water Ocean Basin. A reduced model in an adequate scale was designed and constructed. It was submitted to an almost full equivalent depth and a comprehensive equivalent environment. The later corresponds to representative Campos Basin currents together with critical high crossing waves, which were made to excite resonance of the FPSO (Floating Production Storage and Offloading) hull. Typical moored FPSOs’ motions are much more than other platforms like Semi-Submersibles or TLPs and therefore the SSB is very adequate, since it resists easily to the cited critical environment conditions. Besides describing the system main characteristics, the paper describes the model testing in detail and present main results. Some problematic aspects has been are clearly appreciated for the first time, anticipating that what could happen in full scale. This therefore, requires a design improvement as also discussed.