Traditional mooring systems have become the norm for FPSOs, but a joint industry development project could change that. According to Fernando Lago, of Izar, dynamic positioning could be a viable option.
"There seems to be a growing demand for FPSOs in ultra-deepwater," Lago told attendees at the 7th annual Offshore West Africa conference in Namibia.
There is certainly a need for a cost-efficient early production vessel that can be relocated.
FMC Sofec, Marin, DNV, and Izar formed a JIP to find out if such a vessel can be designed.
"The objective of the JIP is to design a concept that can work off Brazil and West Africa and in the Gulf of Mexico," Lago said.
Design objectives were for a vessel able to operate in greater than 1,500 m, with 125,000-150,000 b/d processing capacity, and 1 MMbbl of storage. The vessel is to support 16 risers and to have a disconnecting turret. The final specification is six thrusters, three fore and three aft, to provide dynamic positioning capability.
Though the ultra-deepwater DP FPSO is only in the concept stage, preliminary testing has been promising, with normal operations maintainable using only four of the six thrusters for most of the operations tested, Lago said. Tests included simulated squall conditions and 10-year storm conditions in the Gulf of Mexico. The tests were carried out under ballast and full load conditions with similarly encouraging results, Lago said.