Subsea Solutions in the Pre-Salt Development Projects

Abstract

Abstract This paper presents the technical solutions adopted and implemented to develop the Brazilian pre-salt reservoirs, covering the main aspects of the subsea production systems already installed and in operation, that allowed overcome the challenges and turn the ultra deepwater pre-salt production into a reality that currently produces more than seven hundred thousand barrels per day. The characteristics related to this particular ultra deepwater scenario are presented, highlighting the ones that demanded to push the envelope of the available technological solutions, considering the conditions are more severe than typical ones from the previous experience with Campos Basin development projects: presence of CO2 and H2S contaminants in the produced fluids; higher internal pressure; high CO2 content gas injection; deeper waters and more severe metocean conditions. The aspects related to subsea trees, control systems, subsea manifolds, diverless connection systems, subsea flowlines, umbilicals and risers for the production systems are presented, as well as the flow assurance issues. The risers and pipelines for produced gas flow to shore are also covered. Considering the large number of projects that would be required to develop the Brazilian pre-salt province, different riser system solutions were developed and applied, being now field proven and available for the industry. Several firsts and records were established and are presented. The effort related to subsea equipment standardization, to cope with the large number of systems to be installed, is also part of this paper. Similarly to the situation of Campos Basin in the 80's, playing the role of a big laboratory for technology development towards deep water production, Brazilian pre-salt scenario, and specially Santos Basin pre-salt province, is nowadays the site where technology development is taking place for ultra deepwater production of high GOR oil with variable CO2 content. Subsea systems are enabling such production and this technology enhancement will contribute for the future development of other areas with similar characteristics.