Búzios Field: Coupled Model to Face the Geomechanical Challenges of the Giant Carbonate Offshore Field

The Búzios Field, located in the Santos Basin, is a vast offshore pre-salt reservoir with significant oil production potential. Spanning an area of 852 km2 at a water depth of 2000 meters, it lies beneath a 2000 m layer of salt and a 1000 m interval of post-salt sediments. Commerciality was declared in 2013, following its discovery in 2010. To understand the geomechanical effects due to reservoir production, factors such as fault behavior, compaction, subsidence, deformations, and compressibility were considered. A one-way coupling procedure using the GeomecBR, Petrobras' in-house software, assessed the geomechanical response. The developed geomechanical model covered an area of 145 km × 145 km and a vertical length of approximately 10 km, comprising over 50 million elements. It integrated various data and disciplines, involving a multidisciplinary team to calibrate the model and enhance the reliability of future forecasts. This paper outlines the methodology used to construct the geomechanical model for the Búzios Field and highlights its key findings. Understanding the geomechanical behavior improves the safety and efficiency of production operations and contributes to the broader understanding of pre-salt reservoirs in the Santos Basin. 1. INTRODUCTION Búzios Field, located in the Santos Basin approximately 180 km off the coast of Rio de Janeiro, is a giant pre-salt carbonate reservoir. It covers an area of 852 km2 and has an average net pay of 400 m. Situated at a water depth of 2000 meters, the field is below 2000 m of salt and 1000 m of post-salt sediments. Discovered in 2010, it was declared commercially viable in 2013 after seismic acquisition and testing. With excellent oil production potential and strong reservoir communication, Búzios Field has proven to be a significant asset for Petrobras (Rosa, 2022). The field is divided into 12 moduli, each produced by a Floating Production Storage and Offloading unit (FPSO). Five FPSOs have already been installed, each with a processing capacity of 150 kbpd. Notably, four of these FPSOs were deployed in less than two years, enabling it to reach the record of 600 kbpd of production in this period. By 2028, when the field will be fully developed with over 170 wells, the total processing capacity is expected to exceed 2 million boed (barrels of equivalent oil per day).