Located in south east region of Brazil between the Campos basin to the north, and the Pelotas basin to the south, Santos Basin covers an area of 352,000 km². Petrobras discovered more than 40 Bn boe, in Pre-Salt Play in the last decade. This geological play is the home of the supergiant and giant light oil fields such Lula, Sapinhoá, Búzios, Libra, franco, Guara, Iracema, Iara, Jupite, etc. In the last five years, the average annual daily production of the pre-salt wells grew from ~ 100 Kboe/day to over 1,000 Kboe/day at the end of 2016.

There are two main source rocks in the Santos Basin, the Hauterivian-Aptian pre-salt lacustrine shales of the Guaratiba Group, correlative to the Lagoa Feia Formation in adjacent Campos Basin, and the Turonian-Maastrichtian deep-water shales of Itajai-Açu Formation. Most of the giant oil fields in the Santos basin were charged from the Hauterivian-Aptian shales. Main reservoirs in the basin are the Hauterivian-Aptian carbonates (microbialites) of the Guaratiba Group, followed by Turonian-Maastrichtian turbidite sandstones of the Itajai-Açu Formation (Ilhabela Member) and shallow platform sandstones of the Campanian-Maastrichtian Juréia Formation.

The Santos Basin studies are a landmark on the understanding the hydrocarbon generation and migration process, oil and gas accumulation, and losses in the basin, throughout geological time.