De-Risking a Heavy Oil Project Development Through an Early Production System

Abstract This paper discusses in detail the Atlanta Early Production System (EPS) strategy to de-risk the Atlanta field development. The Atlanta is a post-salt oil field, located in the Santos Basin, BS-4 Block, approximately 185 km from coast of Rio de Janeiro, Brazil, in water depths of 1,550 meters, represents one of the most challenging heavy oil developments in ultra-deep waters. The EPS phase, initiated in May 2018 with FPSO Petrojarl 1 adapted by Altera (former Teekay) designed as a crucial step to validate key technical aspects, collect reservoir data, and reduce uncertainties before the Full Field Development (FFD) phase, while generating some revenue to the company. Introduction"Discovered in 2001, the Atlanta Field represents a unique technical challenge in ultra-deepwater development. The field comprises an unconsolidated sandstone reservoir at a temperature of 105.8°F (41°C) at −2,315 m, with 800 m of overburden thickness in a 1,550m water depth environment. The Eocene interval exhibits exceptional petrophysical properties, characterized by high net-to-gross sands (82-94%) with an average porosity of 36% and permeability ranging from 4 to 6 Darcy. These excellent rock properties, however, are offset by the challenging fluid characteristics: heavy oil (14° API), high viscosity (228 cP at reservoir conditions), and highly acidic content (total acid number of 9.8 mg KOH/g). These characteristics demanded innovative solutions for artificial lift, flow assurance, and topside processing facilities." (Marsili, 2015) To ensure its economic feasibility, the development concept required a good well productivity, sand control, completion, high power artificial lift pumping system, specific flow assurance procedures, and most importantly, an experienced operational team.