Relating petroleum system and play development to basin evolution: Brazilian South Atlantic margin

Abstract

We review the structural genesis and evolutionary history of basins along the Brazilian South Atlantic margin from the Sergipe-Alagoas (north) to the Pelotas basin (south), and demonstrate the links with petroleum system and play development. In our approach, we first break basins down into their tectonostratigraphic megasequences and define their characteristics, particularly focused on the development of characteristic source- and reservoir-rock intervals. We then compare these megasequences with similar types of megasequences in other basins, thereby providing a means to learn through a greater population of analogues. We demonstrate, using trajectory plots, that these basins experienced a similar tectonostratigraphic basin evolution, resulting in the deposition of many analogue potential source- and reservoir-rock intervals. These give rise to the development of similar types of potential petroleum systems and play (level)s. Although the area is currently being actively explored, large areas remain poorly understood, with unknown source-rock maturity distributions and many unknown/untested reservoirs/plays. This approach allows us to make analogue comparisons between the Brazilian marginal basins in order to evaluate and predict the presence of potential, yet undiscovered or under-explored, hydrocarbon accumulations. Supplementary material: Published source-rock and play properties used in this analysis are available at http://www.geolsoc.org.uk/SUP18536