In the last 10 years, Petrobras has converted 8 existing tankers to operate as FPSOs/FSOs in Campos Basin, offshore Brazil. The lessons learned from the conversion of those Units highlighted the importance of taking into consideration the concepts of constructability and clean arrangement in the design of FPSOs.
The project of FPSO P-50 was developed with those concepts in mind and then, the philosophy of the following main systems was changed from previous FPSO projects:
Cargo and ballast systems: Use of individual submerged cargo pumps, eliminating the cargo pump room and the communication between the cargo tanks;
Sea water lift system for water injection: Use of electric submerged pumps;
Fire Fighting System: Use of Diesel hydraulic fire water pumps with submerged hydraulic driven booster pumps;
Offloading system: Use of reels to store the offloading hose, instead of a chute system;
Marine systems: Development of a new arrangement concept for the main deck marine systems pipe rack;
Mooring System: Use of a spread mooring concept instead of turret system and use of free fall piles to anchor the FPSO.
The Albacora Leste field (Figure 1) was discovered in March 1986 by the wildcat 1-RJS-342A. This 600-km2 field lies 125 kilometers off the coast of Rio de Janeiro, at water depths from 800 to 2,000 meters. The field is comprised primarily of Miocene turbidite sandstones (Ref. 1).
The Field Development will comprise 16 subsea production wells producing 180,000 bopd through individual bundles (Figure 2) to the FPSO P-50 located at 1,240 meters water depth. The water injection, totalizing 35,000 cubic meters, will be achieved through 15 subsea wells. P-50 (Figure 3) is a former VLCC that is currently under a process of conversion to a production Unit.
After processing and treatment in the FPSO, the oil will be stored inside the tanks and later exported to shore via shuttle tankers. The compressed gas will be exported through a 10- inch gas pipeline up to a subsea PipeLine End Manifold (PLAEM) that will be connected to an existing fixed platform through a new 20-inch diameter pipeline. From this fixed platform, the gas will be sent to shore through the existing gas network pipeline.
The first mono-hull floating production Unit to operate in Campos Basin (and one of the first FPSOs in the world) was the former tanker P.P. Moraes. This 33,000-dwt tanker was built in 1959 and, in 1975, it was jumboized to 54,000 dwt. In 1979, a 60,000 bpd process plant was installed on the ship to allow it to operate in the Garoupa field. In 1987, P.P. Moraes was relocated to Albacora Field. The system operated continuously from September 1987 up to March 1993 with no significant downtime (Ref. 2, 3 and 4).