Subsea Separation Systems
Authors: Pagot P.R. , Werneck M. , Assayag S. , Cerqueira M.B. , Herdeiro M.A.N. 
Published: October 2008

Abstract
Petrobras will install the first Petroboost subsea prototype in the world in early 1997, in the Marimba oil field in Campos Basin, Brazil.
This paper presents a general description of Petroboost, the main features of the production system in Marimba, the current situation of the project, and future steps Petrobras intends to carry out to declare this technology available and ready to be used in deepwater fields in 1997. The success of the prototype in Marimbh and the satisfactory completion of the test programs of some critical items are enough to declare the Petroboost technology available for deepwater.

Introduction
Petrobras has invested time and money in the development of sub sea separation systems (SSS) and considers that technological innovation attractive for application in deepwater fields, besides marginal fields in shallow water. Production flow rates and final oil-recovery factors higher than the ones obtained in a conventional way are expected too. Others benefits are possible reductions in operational and investment costs as well as a reduction in the number of required platforms to exploit a new area, as explained the Ref. 1 and 2. Petrobras is so confident in those benefits that it intends to install two prototypes in real sites in the near future. One of them will be a gas driven (Petroboost) and the other an electrically driven separation system, helical separation and pumping in dummy well. About the electrically driven, Petrobras is sharing efforts with other international oil companies, but Petroboost development is being conducted internally by Petrobras staff.

History
Petrobras received a patent based on the Petroboost concept in 1986. Since then, the company has performed several studies and analyses and has designed the Petroboost production system for several oil fields. As the Petroboost system hasn't been tested before in any place in the world, it was important to investigate some technical issues. The Ref. 3, a M. SC. thesis entitled "Process Simulation in a Sub sea Separation System," analyzed the transient phenomena that would happen in gas and oil pipelines associated with the Petroboost. Petrobras encouraged work on the thesis and constructed a pilot plant at the Petrobras research and development center where the company has conducted many tests so far.
Toward being qualified to take the unavoidable decisions we were able to foresee at the beginning of the Procap (Petrobras Technological Innovative Program on Deep Water Exploitation Systems) 2000 program, Petrobras conceived a comprehensive working plan in which the first activity was to define a precedence, among four SSS conceptions, called technological lines (TL). Two of those lines were electric driven and the others were high-pressure gas driven. For each one of the lines, Petrobras designed and developed preliminary projects for two different sites, one soft, the Albacora field and another one severe, the Marlim field. At the end of the work, Petrobras made a global comparison among ail TL's and declared Petroboost was ready to be prototype.