FPSO marine operability study

When our supermajor client required a study to be carried to understand the FPSO heading response with varying degrees of propulsion degradation, with our in house marine engineers and naval architects, the natural choice was to approach the Apollo team.  Our client required an accurate, practical and confident study to help them make decisions that would have considerable impacts both commercially and operationally.

Using traditional engineering and cutting-edge modelling techniques, Apollo were able to look at multiple scenarios and make recommendations to ensure our client could plan their offloading operations safely and effectively, even in the event of lost thruster availability.

Client problem:

• Our client required a study to understand the heading response with varying degrees of propulsion degradation
• The aim is to understand – at feasibility level – the impact of impaired heading control in terms of tanker offloading windows and supply boat operations

What we did:

• Investigated the ability of the FPSO and its shuttle tanker to maintain position within relative position limits, in the event that the FPSO thrusters become unavailable
• Modelled two scenarios: one representing normal operating conditions and the other representing a strong current partially reversing on a tidal cycle, with the FPSO allowed to freely weathervane
• Assessed relative, motions of the vessel using OrcaFlex

Value / Benefits:

• The key outcome was an assessment of the risk of rapid heading changes during shuttle tanker operations within degraded thruster performance
• Results showed rapid heading changes in light wind and maximum annual currents and an assessment of the amount of thrust required to maintain stable headings
• Outlined significant impacts to offloading operability if there is no thrust capacity
• Apollo’s approach ensured clear outcomes that allowed our client to make confident decisions to minimize downtime