Chapter 11: Breaking Barriers and Paradigms in Presalt Exploration: The Pão de Açúcar Discovery (Offshore Brazil)

Abstract Pao de Acuar is certainly one of the most impressive and challenging hydrocarbon accumulations found in the prolific Campos Basin, offshore Brazil. This discovery opened a new frontier for exploration in Brazil’s ultradeep waters, in depths ranging from 2500 to 2900 m (8202 to 9514 ft). Pao de Acuar is the third discovery made by a consortium integrated by Repsol Sinopec Brasil (operator), Statoil do Brasil, and Petrobras in the Concession BM-C-33, with estimated resources of 700 million bbl of light oil and 3 tcf of gas. This discovery is the result of the integrated work of a multidisciplinary international team using some of the most advanced technologies available today in the oil exploration industry in seismic imaging, drilling, formation evaluation, and fluid-rock sampling analysis. This discovery consists of a significant hydrocarbon column hosted within a unique reservoir made up of a variety of basic volcanic rocks overlain by pervasively silicified microbial carbonate platform/ramps, grading toward profundal lake facies. This chapter summarizes the main results of the exploration and ongoing appraisal work regarding this unique hydrocarbon accumulation, highlighting both the complexity of the discovered reservoirs and the operational and technical challenges faced, and still to overcome, before beginning production.