ICE 2022


The offshore Pará-Maranhão Basin (PAMA) is situated in the western part of the Equatorial Margin of Brazil. The Pelotas Basin (PEL) is the southernmost offshore basin in Brazil. They are 4,500 km (2,800 mi) apart from each other, having 14 other offshore basins in between them. Although distant in space they present very similar petroleum geology and potential, especially regarding the Marine Cretaceous Anoxic Shales–Upper Cretaceous Turbidites petroleum system. Another shared characteristic is the number of wells drilled in their deep and ultra-deep-waters; only two. Very large tracts of unexplored basins, presenting large thicknesses of sediments and having several geologically analogous areas with large oil and gas discoveries and production, are usually indicative of frontier areas ripe for great exploratory success. The similarity starts with the source rocks. Turonian and Coniacian marine anoxic shales are the main source rocks in the deep waters of the Equatorial Atlantic conjugate margins. Aptian, Albian and Turonian marine anoxic shales are the candidates for hydrocarbon sourcing in PEL. Both deep water areas in the basins are devoid of rift sequences, their sedimentary section resting directly upon volcanic rocks; oceanic crust in PAMA, SDR`s in PEL. The petroleum system, thus, is developed in the Drift Sequence. Both Drift Sequences are practically undisturbed by structural deformation, exception being gravitational cells. Turbidites are well developed in the Late Cretaceous sections of both basins, being stratigraphic traps the dominant accumulations envisaged in such situation. Migration routes are sub-seismic fractures and faults or visible faulting in subtle drape folds atop volcanic highs. An important secondary target in both areas, visible in new vintages of 2D seismic surveys, consist of Albian carbonate constructions developed on top of buried volcanos (atolls). The similarity of these petroleum systems with other analogous proved petroleum provinces such as Ghana-Ivory Coast, Guyana-Suriname in the Equatorial Atlantic and Sergipe-Equatorial Guinea, Santos and South Africa in the South Atlantic are tremendous. The amount of leads visible in new 2D seismic data is high. It is only a matter of time that these two basins start yielding significant discoveries of stratigraphically trapped oil and gas accumulations.