Atlanta Field: Constructing Long Horizontal Wells in a Challenging Environment

Abstract

Atlanta is a post-salt oil field located offshore Brazil in the Santos Basin, 150 km southeast of Rio de Janeiro. The combination of ultra-deep water (1550m), heavy and viscous oil (14 API), unconsolidated sandstones, low overburden (800m), faulted reservoir rock, etc., composes a unique and challenging scenario for which the remarkable solutions applied have been already detailed (Marsili et al. 2015; Pedroso et al. 2017; Monteiro et al. 2015; Pedroso et al. 2015; Rausis et al. 2015; Pedroso et al. 2015). The Atlanta field project was planned to be developed in two phases: the Early Production System (EPS) with three production wells, and the Definitive Production System (DPS) with up to nine wells. No injection wells have been planned. In 2013 and 2014 the first two wells, here called ATL-2 and ATL-3 (ATL-1 was a pilot well), were successfully drilled, completed, and tested as described in the above references. In May 2018, they started production. After almost one year and 5,000,000 bbl of produced oil, the third EPS well was constructed. The lessons learned in each phase of the well construction - drilling, lower completion, and upper completion - were applied in the third well, repeating the good operational performance. An analysis of this comparative performance is presented. Technology improvements were implemented, such as the use of autonomous inflow control devices (AICD), the use of micro-tortuosity logging to better position the electrical submersible pump (ESP), the use of an annulus diverter valve (ADV) to avoid the pressure drop across the ESP in case of failure, etc. The result was a well constructed ahead the planned time with a Productivity Index (PI) that exceeded expectations.