Ultra-deepwater seismic plays offshore Brazil — Future drilling off Santos and Campos Basins

Abstract

Contemporaneous seismic data acquisition in the Santos and Campos Basins offshore Brazil have focused on image characterization of deepwater and ultra-deepwater reservoirs and their relationship with hydrocarbons originating from synrift source rocks. Our interpretation has mapped the stratigraphy of postsalt turbidite reservoirs, and, on the presalt lithology, it has uncovered the underlying synrift sequences that embrace oil-bearing source rocks and the prolific, recently discovered, microbialite carbonate reservoirs. The new phase in geophysical data acquisition and offshore drilling that started in 1999 bolstered the Brazilian offshore petroleum production to record levels. The new, massive, nonexclusive, speculative 2D and 3D data acquisition surveys conducted offshore the Brazilian coast far exceed the amount of all existing cumulative vintage data. Deepwater drilling programs probed the interpreted new prospects. As whole, the modern geophysics data libraries offshore Brazil brought in the technology era to seismic interpretation, reservoir characterization, and geosteering operations in deepwater development drilling. Still, regional interpretation mapping of the outer shelf, slope, deepwater and ultra-deepwater provinces of the Santos and Campos Basins indicates plenty of prospective future drilling in the salt locked minibasins of the ultra-deepwater provinces. Salt tectonics shapes the architecture of these basins; hence, postsalt deepwater turbidite plays were readily interpreted from seismic amplitudes of the modern data that also allow for resolution images of the synrift source rocks, salt architecture, migration paths through faulting and salt windows, reservoir characterization, and regional seal mapping. The new techniques of prestack depth migration have enabled uncovering the imaging structure of the synrift that led to characterization of the presalt carbonate reservoirs and discovery of giant accumulations. Future offshore exploration will continue aiming at postsalt deepwater and ultra-deepwater minibasins plus presalt plays under the massive salt walls, still an underexplored frontier.

Interactive Deep Learning for Detailed Seismic Interpretation of Structurally Complex Areas: A Campos Basin Case Study

“…The structural framework of these deepwater plays is entirely controlled by salt tectonics. The salt fairway becomes progressively narrower towards the north (Bahia and Sergipe), and no salt is encountered in the equatorial transform margin basins (Fainstein et al, 2019). Syndepositional differential loading within the turbidite sequences were the main driving mechanism for salt evacuation.…”

“…Campos Basin turbidite reservoirs are encountered in the upper and lower continental slope from the Miocene to Upper Cretaceous and in distal marine turbidite channel sands of the lower slope. Recoverable reserves for the giant Albacora, Marlin and Roncador Fields are expected to exceed 10 BBO throughout their time span of production (Fainstein et al, 2019).…”

“…The deepwater plays required substantial exploration investments, such that during the contemporary period after 1997 up to the first decade of the 21 st century, more than 200 exploratory wells have been drilled on water depths greater than 1 km. New oil discoveries have been made in the Santos, Campos and Espírito Santo Basins (Fainstein et al, 2019). In the mature Campos Basin, a focus on detailed interpretation is key for creating detailed reservoir models, which are required for continued production and for the opportunity to add satellite opportunities.…”