Investigation of roll damping effects on deep water FPSOs with riser balcony through global coupled analysis

ABSTRACT

This work investigates the asymmetric behaviour of the roll motions and damping effects on a Floating Production Storage and Offloading vessel (FPSO) with riser balcony on portside in deep-water scenarios. The focus is on assessing the importance of employing a fully coupled analysis methodology to consider all nonlinear dynamic interactions between the hull, mooring lines and risers; and to stress the differences from the traditional uncoupled methodology, in terms of both the roll motions and the riser top tensions. For this purpose, a set of simulations are performed using uncoupled and coupled models, under regular and irregular beam seas, perpendicular to the vessel centreline. Results from the coupled analyses show significant reductions in roll motions and riser tensions, indicating that coupling effects are relevant and must be considered by using accurate coupled analysis tools.

KEYWORDS:

• Roll damping
• risers
• coupling effects
• global analysis

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was partially supported by the Brazilian funding agencies Conselho Nacional de Desenvolvimento Científico e Tecnológico [grant numbers 308873/2017-3, 301474/2017-6]; Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro [grant number E-26/202.767/2017]; and Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, finance code 001.