Marlim 3-Phase Subsea Separation System: Project Overview and Execution Stragegy

Abstract

Abstract The Marlim SSAO 3-Phase Subsea Separation System is the world's first systemfor deepwater separation of heavy oil and water which re-injects water in thesame producer reservoir. The major difficulty for reinjection in the producerreservoir is the strict water quality requirement, limiting maximum solidparticles (sand) and residual oil content. This challenging application posedinnumerous challenges to the project and the solutions developed give aworldwide pioneering characteristic to this system. This paper provides anintroduction to the Marlim SSAO System and is one of a set of papers presentedat OTC-2012. It gives a project overview from the topside facilities to thesubsea production systems. Included also are the project drivers, main premisesand objectives, and the management strategy used in the execution of such asophisticated. Introduction The Marlim SSAO 3-Phase Subsea Separation System (" SSAO" being the acronym inPortuguese for Separação Submarina Água-Óleo - Subsea Oil-Water Separation) isa pilot system for oil-water subsea separation systems. The project has as itsprimary goal to prove and to develop the technology basis for potentialapplication in several other existing mature fields to optimizeproduction. The costs of processing and disposing of water in the topside facility arehigh, such that the possibility of separating water from oil on the seabed, anddirect re-injection, reduces operational costs and simultaneously debottleneckstopside facilities, allowing increase of production. Another key feature is the contribution to optimize the oil process fortransportation and the water process for disposal. On new projects these maylead to smaller platforms for the same process capacity, increasing productionand in some cases, increasing oil recovery factor. Initially the SSAO technology will be applied in fields that are trending tohigh watercuts like Marlim, Marlim Sul, Albacora, and Golfinho and later it isexpected to be used in the Pre-Salt fields. The SSAO is also an environmental friendly technology as it reduces wastedisposal to sea. Considering that environmental legislation is continuouslybeing made ever stricter for disposal of water with oil content, thistechnology contributes to the sustainability of the oil industry in thefuture. In order to establish the design parameters produced water reinjection testswere performed on the Marlim Field. To ensure that the system would achievethese parameters, a Technology Qualification Program was performed for the mainprocess stages and some specific key components were also tested for their newmission. The introduction of subsea processing in a mature field still requires newequipment to be installed topside. Finding room on the P-37 floating productionunit was a very challenging task. Modifications to the unit were required andthis had to be addressed and managed starting in the early phases of theproject, with very detailed planning to enable safe installation andcommissioning while the platform was producing. Due to the size and challenges of this R&D project, there was a high levelof involvement from both PETROBRAS management and technical personnel, with theproject execution being very closely monitored employing live Risk Managementon an almost day by day basis.