The use of floating production, storage and offloading (FPSO) systems converted from a very large crude carrier (VLCC) has been deemed a practical solution compared to the costly and time-consuming construction of custom built floating systems. At the time of the Barracuda and Caratinga Project conception, in the late 90ths, with the oil barrel price between US$ 12 and US$ 15, the conversion came in as an attractive alternative in order to increase the economic feasibility of the project. As most of the oil tanker fleet used for conversion was built in 80's decade, the design requirements and component specifications to ensure FPSO's integrity and operation performance for next 20 years without docking have become of paramount importance. In order to overcome this challenge, PETROBRAS has adopted the lessons learned from previous FPSO developments in the Campos Basin, while using both proven and new technologies in the Barracuda (P-43) and Caratinga (P-48) FPSOs. Besides the conversion approach, another important strategy for the project implementation was the twin design of the FPSOs. Instead of opting for a distinct design, customizing the production units for the reality of each field, the requirements for the production units were matched and a single design was adopted, allowing a reduction in the construction costs and a larger increase in the project economic feasibility. After a short description of the fields development, this paper describes the development of P-43 and P-48 FPSO for the Barracuda and Caratinda fields respectively, focusing on the unique features of the FPSO's design and the key project decisions that affected the conversion design, construction and installation of such units.
In order to develop offshore deep-water oil fields, PETROBRAS started to convert vessels to operate as floating production, storage and offloading systems (FPSOs). In today's economic environment, these systems are widespread in the offshore industry and have proven to be an effective solution for the development of the fields. Barracuda and Caratinga Project is one of the cases where this conversion occurred. Barracuda and Caratinga Project was developed in two stages: the Pilot System stage and the Definitive System stage. The Pilot System, which purpose was to anticipate the production and collect information of the fields, started its operations in September 1997, exploring the fields referenced through the FPSO P-34. Ten production pilot wells from both Barracuda and Caratinga fields were connected to FPSO P-34, producing around 45,000 barrels per day until its demobilization, which occurred in September 2003. The Definitive System consists on the construction of two FPSOs: P-43 and P-48 connected to 54 wells through a subsea system, for the operation in Barracuda and Caratinga fields, respectively. In order to increase the economic feasibility of the Project, at the time of its conception, it was decided to convert two VLCCs units (Stena Concordia and Stena Continent) in the FPSOs P-43 and P-48, respectively.
Barracuda and Caratinga fields, located in Campos Basin in Brazilian Coast, are approximately 12,5 km separated from each other.