Major Types Of Deep-Water Reservoirs From The Eastern Brazilian Rift And Passive Margin Basins

Turbidites and associated deep-water facies comprise the most important petroleum reservoirs in Brazil.<br>They contain original in place volumes of 57.2 billion bbl of oil, and 27.5 trillion cubic feet of gas, and total<br>reserves of 12.5 billion bbl of oil, and 8.3 trillion cubic feet of gas. Brazilian petroleum-bearing turbidites occur in<br>(1) CarboniferouslPermian, glaciomarine pre-rift (interior cratonic) successions, (2) Neocomian to Aptian,<br>lacustrine rift successions, and (3) Upper Albian to Lower Miocene, marine passive margin successions. Most of<br>the petroleum accumulations are distributed along the eastern Brazilian margin, which tectonic and sedimentary<br>evolution is linked to the Neocomian breakup of Gondwana and the subsequent opening of the South Atlantic<br>Ocean. Turbidites comprise 553 production zones from 171 oil and/or gas fields, mostly concentrated in the<br>Campos, Reconcavo, SergipelAlagoas, and Espirito Santo basins. This paper presents an overview of the<br>sedimentary facies, high-resolution stratigraphy, sandbody geometry, and reservoir heterogeneities of the major<br>types of Brazilian deep-water reservoirs, which include (1) gravel/sand-rich, turbidite channel complexes, (2)<br>trough-confined, gravel/sand-rich turbidite lobes, (3) unconfined, sand-rich turbidite lobes, (4) sand/mud-rich<br>turbidite lobes, (5) gravel/sand-rich turbidite and debrite aprons, (6) deposits of sand-rich, lacustrine density<br>underflows, (7) deposits of sand/mud-rich debris flows, and (8) deposits of sandy bottom currents.