Campos Basin - Subsea Equipment: Evolution and Next Steps

Abstract

Abstract Since the first subsea well started producing in Campos Basin, this province has turned into a big laboratory where innovations and different concepts have been tested, ranging from one-atmosphere chambers to diverless guidelineless deepwater subsea trees and manifolds. The need to produce successive discoveries in increasing deepwaters imposed the challenge that sparked the continuous technology development in the past 25 years. The subsea trees evolution in the world is very much associated with the developments tested in this province. It starts with the dry subsea trees in wellhead-cellars in Garoupa field, passing through the shallow waters diver operated trees, the development of the lay-away technique and, furthermore, development of the diverless vertical connection system and the guidelineless deepwater subsea trees. The strategic effort on standardization of subsea tree interfaces provided operational flexibility and increased rationalization to deal with wellheads, trees, tools and completion risers of different manufacturers for hundreds of wells. Evolution of subsea manifold architecture and modularization concept has been present along the development of several fields as Garoupa, Bonito, Linguado, Albacora, Marlim and Roncador. The same for subsea controls, including direct hydraulic and electro-hydraulic multiplexed systems. Subsea flowlines, umbilicals and risers were also developed for a variety of conditions of water depth, production facility (semi-submersible, FPSO, monobuoy), fluid characteristics and thermal insulation requirements. These developments included an extensive use of flexible tubes, steel pipelines and the pioneer Steel Catenary Riser connected to a semi-submersible production unit in deepwater. Adding new components to the toolbox of subsea engineers, boosting systems have also been developed, as the first in the world subsea completion with an Electric Submersible Pump (ESP) in Carapeba Field and the Marimbá Subsea Separation System. Supported by the operational experience acquired throughout the years and motivated by the challenge to develop the ultra deepwater discoveries, other technological developments are being conducted by Petrobras. This paper presents the evolution of subsea equipment so far, the development efforts being carried out and the next steps to meet the future demands. Introduction Campos Basin initial production development was based in the widely use of Early Production Systems (EPS), from Enchova field at 120 m water depth (WD) up till now in Roncador field at almost 2,000 m WD. The use of EPS confirmed to be a reliable and cost effective solution being extended for the definitive offshore fields developments. This concept implementation required an intensive use of subsea trees, manifolds and flexible pipes for static and dynamic applications, leading Petrobras to focus in the subsea hardware technology development to overcome the big challenges of producing in shallow, deep and ultra deep waters, as highlighted bellow: The use of drilling equipment for the first Petrobras EPS in 1977, with a test tree (EZ tree) suspended by a drilling rig inside the Blow-Out Preventer (BOP) stack to produce the well 3-ENO-1-RJS at 120 m WD.