CAIRU FPSO REQUIREMENTS AND DESIGN

Abstract

Cairu FPSO is one of the five FPSOs' to be installed up to 1998 at Campos Basin, Offshore Brazil. Designed to operate in Marlim Field for twenty years without docking, carrying out off-loading operations about each six days, and handling more than 150 000 bopd during its operational life, this unit, like the others to be installed by has its conversion contract subject to basic requirements established in order to guarantee operational reliability Constructed in 1974 at Ishikawajima Shipyard, and pertaining to PETROBRAS fleet, CAIRU is a VLCC (Very Large Crude Carrier) with 280 000 dwt. Due to the absence of double hull and her high operational costs as an oil tanker, she was available to be used as a Production and Storage Unit. Allied to that, Technical and Economic Feasibility Study developed focusing oil drainage in Campos Basin has shown the advantages of employing oil storage units exporting via shuttle tanks over the option of constructing a pipeline network. Taking advantage of the installation of an oil storage unit, an oil treatment plant to process the fluid from P-18 and P-20 (semi-submersible platforms already installed at Marlim field) was also planned. In order to allow the mooring of this FPSO a turret system was incorporated in the design, providing also facilities for the connection of eight risers. The aim of this paper is to present a brief description of the systems which compound Cairu FPSO, their main requirements, the most relevant difficulties and solutions adopted. Innovative solutions, such as the employment of cargo tanks as process coalescer tanks and crude oil as a combustible for boilers and furnace are also highlighted. Transactions on the Built Environment vol 29, © 1997 WIT Press, www.witpress.com, ISSN 1743-3509