One Company's Experience on Ship-Based Production System
Authors: Mastrangelo Carlos Ferraz 
Published: October 2008

The discovery of giant deep-water fields, namely Roncador, Barracuda, Marlim and Albacora in Campos Basin, offshore Brazil, has allowed Petrobras a remarkable increase in national oil production.

Of the various floating production concept suitable for oil field development, the FPSO for deep and ultra deep waters stands out as the most attractive one, in the light of technical and economical aspects.

In fact, the experience of Petrobras began in Feb 1979 with an FPSO with a Tower-Yoke system. PETROBRAS has installed, since then, eight FPSOs / FSOs. Up to June of 2000 three more units will be installed and planned to install five more units by the end of 2002.

This paper assesses the global efficiency and production loss causes, process plant uptime, oil spill problems, meteocean data for design and its critical conditions for risers pull-in and lightening operations.

The intention of this paper is to address the operational feasibility of FPSO systems operated by Petrobras in its eight units as well as to emphasize that this experience shall be used to improve the other eight new units.

Introduction

Ocean terminal facilities utilizing Crude Oil Tanker Ships were employed by the Oil Industry as early as sixty years ago. In the beginning, a tanker was simply connected to a single point mooring (CALM) by conventional hawsers where it was used as a combination of buffer storage vessel and shuttle tanker mooring platform. A further step in the evolution of this type of unit came about in Brazil in 1975, when process facilities were designed to operate using a ship-based unit. Although conceived in 1975 this system only began operating in February 1979.

More recently, technical and economical feasibility studies for giant oil fields discovered in deep (400 to 1000 meters) and ultra-deep (over 1000 meters) water depth as Barracuda, Albacora, Marlim and Roncador field, in areas with no export pipelines, indicated the FPSO as a cost-effective alternative.

The main advantages of this concept are the low initial investment, high applicability for deep water, high operational flexibility and most recently its higher operational efficiency.

In Brazil eight (8) FPSO/FSO units are already installed and eight (8) units more are under construction, conceptual or basic design stage to be installed until 2002. Experience gained from operating this type of unit has been useful for determining technical specifications, life expectancy design for future conversions and keep us confident that operational and safety procedures are the main concern to prevent oil spills.

This paper will emphasize the experience on this type of unit as well as its reliability. Roughly we can summarize operational results and compare them with those of Semi-Submersible option as well as old-fashioned solution as Fixed Platform.

As the FPSO concept designed for Campos Basin requires offloading through oceanic terminal we intend to analyze both operational production efficiency as well as its offloading uptime.

Background

We have previous experience on the operation of the Spread-Mooring, Tower-Yoke, Calm System, CALM-YOKE, and presently Turret System.