Pre-Salt Limestone Plays in Campos and Santos Basins, Brazil: Additional Potential Identified

Abstract

AbstractThis study summarizes the pre-salt hydrocarbon play elements in Brazilian offshore and identifies additional exploration potential within the BMS-50/52 and BS-1_South 3D seismic surveys areas within the Santos Basin and of the BC-200 merged and reprocessed PSDM survey located within the deep to ultra-deep waters of the Campos Basin. Several large opportunities have been identified based on seismofacies recognition and preliminary seismic interpretations of 3D Multi-Client PSDM surveys.The BMS-50/52 and BS-1_South 3D surveys are within the pre-salt play polygon of the Santos Basin. The pre-salt exploration trends identified in the these surveys are: a) Rift/Pre-rift play in the central-west, with hydrocarbon accumulations in siliciclastic reservoirs of the Paleozoic (pre-rift) to the Lower Cretaceous rift succession in fault traps; b) Sag/Rift Limestone Edge Play (Sagitário trend), comprising structural or paleo-topographic traps beneath the base salt in microbial platform limestone, with occasional isolated microbial buildups; c) The Carcará North/Itaipava Sag-Rift Limestone Play which is a light-oil trend that includes the Carcará discovery in BMS-8, with hundreds of square kilometers of closures at the base salt and relief reaching 350 to 400 meters. In this trend, reservoir facies are expected to have excellent reservoir properties and are interpreted as very large microbial buildups, oriented along fault zones which are located at the edges of the previous rift horsts.3D seismic interpretation of the pre-salt section in the BC-200, deep to ultra-deepwater area in the Campos Basin has allowed the delineation of several pre-salt plays: i) Structural Play in coquinas (Late Rift to Sag); ii) Stratigraphic/Combination Play in coquinas (Late Rift to Sag); iii) Microbial Build-up Play on rift shoulders (Sag microbialites) and; iv) Microbial Build-up Play on volcanic complexes, potentially large limestone units beneath the salt nucleated on top of large volcanic complexes in distal settings.