Pre-salt Brazil — subsurface mapping experience.

Overview

The Brazilian pre-salt is one of the defining offshore petroleum provinces of the 21st century. Discovered in 2006 and reaching serious commercial scale in the mid-2010s, the Santos and Campos basin pre-salt plays have transformed Brazil's production outlook and reshaped Petrobras's corporate strategy. Cumulative pre-salt production passed 3 Mbpd in 2023.

The play is technically challenging: targets sit at 4,000–6,000 m total vertical depth, through 2,000 m of water column plus 3,000 m of overlying salt and clastic sequences. Seismic imaging through thick salt has been the defining technical problem in the basin, and 40+ years of incremental seismic improvement has mostly solved it — but at enormous cost per interpreted block.

Remote NMR mapping has been deployed in the pre-salt primarily for block-scale pre-license screening in Brazilian bid rounds (ANP license rounds typically have 4–8 week evaluation windows), and as a pre-seismic substance screen ahead of seismic reprocessing or new acquisition.

Mapping considerations

Pre-salt-specific considerations:

• Deep water column. 1,500–3,000 m of water above the seabed. Effective sub-seabed penetration reduces proportionally; most pre-salt targets are well within accurate range.
• Thick salt overburden. Seismic imaging struggles through the salt; NMR-based signature classification is insensitive to salt thickness, which is a structural advantage.
• Mature regional calibration. 15+ years of producing wells and extensive publicly-disclosed technical data from ANP bid-round data rooms enable strong regional anchoring.
• High-value bid windows. Brazilian license rounds typically offer 4–8 week evaluation windows, during which a full 3D seismic acquisition program is impossible but a remote screen is feasible.

Typical use cases in this basin

• Pre-bid block screening in ANP license rounds
• Sub-salt hydrocarbon confirmation where seismic is ambiguous
• Farm-in diligence on partnered blocks
• Selection of blocks for reprocessing vs new seismic acquisition
• Risk ranking for deepwater drilling capital allocation