The Design of an FPSO To Operate in Gulf of Mexico
Authors: Ribeiro Orlando , Palagi Cesar , Mastrangelo Carlos , Corte Antonio 
Published: October 2008

This paper addresses the design criteria for a Floating, Production, Storage and Offloading (FPSO) unit with disconnectable turret to be installed in ultra-deep waters of the Outer Continental Shelf (OCS) of Gulf of Mexico (GoM). The FPSO is designed as part of a phased development plan to allow an early start of production and to gather data to design the full development of offshore petroleum fields. FPSO are applied widely around the world. However, this concept has never been implemented in USA. The main features of the project are as follows: liquid processing capacity of 80,000 barrels per day, gas processing capacity of 16 million standard cubic feet per day, oil storage capacity of 500 million barrels, gas export through pipeline, oil export through shuttle tankers and mooring system in water depth of 8,000 feet with a disconnectable turret.

This paper describes the major advantages and disadvantages of the use of FPSO as the First Phase (Early Production) during the development of ultra-deep water petroleum fields in GoM. It also describes the main technical and operational aspects required to fulfill the regulatory standards. Currently, FPSO is the best concept to be applied as an early production during the development of ultra-deep water petroleum fields in GoM, where no oil transport infrastructure is available.

The design of the first FPSO to be installed in USA is a major step towards the early development and production of petroleum fields in ultra-deep waters. The success of this pioneering project depends on the cooperation and support among oil companies, service and goods suppliers and regulatory agencies.

Introduction

Since the first production from Campos Basin, in 1977 the use of Early Production Systems has been a hallmark of Petrobras. At that time the driving force behind Petrobras development programs was the need for immediate production to offset the adverse effect of high oil prices on Brazil's balance of payments.

In the late 80's and early 90's a new driving force emerged: the discovery of the giant Albacora and Marlin fields. At the time of these discoveries there was no proven technology to develop these deep water fields. Only a few wells were producing from water depths greater than 1,000 feet. Infrastructure to work in these depths was extremely limited. Drilling rigs, installation vessels and experienced personnel to tackle the sheer size of these developments were very limited. The development challenge was daunting.

Petrobras, again, used its Early Production and Phased Developtment Approach to develop parts of these major discoveries supplemented by carefully thought out strategies for:New technology developmentAcquire reservoir performance dataAcquire operational experienceOptimize the use of critical resources while encouraging the market to develop new onesEarly cash flow.

The strategy proved very successful and it's been used ever since in other large deepwater developments.

Here in the GoM there has never been the need for a similar approach. GoM discoveries tended to be medium to small in size and from the same plays that exist onshore and in shallow water.