Print this pagePre-Salt in Ultra-Deep Waters of Santos Basin — A Successful Exploratory History
Since late 70’s the geological feature known as the Plateau of São Paulo, located in Santos Basin, has attracted Petrobras exploratory attention, especially in the region of the Santos External High. This area defines a unique setting on the Brazilian Continental Margin, characterized by the existence of a thick sedimentary column below a massive evaporitic layer deposited at the moment of the early formation of oceanic crust in the South Atlantic. Crustal studies revealed that in areas where the crust was less stretched in relation to adjacent segments it was maintained relatively higher and controlled the deposition of carbonates. The area started to be thoroughly investigated in the year of 2000, after the second ANP bid round, when the exploratory blocks were leased by several consortiums.
All the previously existent geophysical and geological data were examined and a huge 3D seismic survey was acquired in the area. The operations were conducted by Petrobras in partnership with several other companies.
In a record time, several world-class giant oil fields were discovered. The first one, the Tupi Field, in fact a supergiant, was drilled in 2006, and holds an estimated reserve of 5 to 8 billion barrels. The Iara Field, located in the same original block as Tupi, is another world-class giant oil field. It holds estimated reserves of 3 to 4 billion barrels, as announced by the Petrobras, BG Group and Galp Energy Consortium. Several other giant oil fields were also discovered in the ultradeep waters of Santos basin and are awaiting the appraisals wells to be drilled. In May of 2009 the first oil was produced from Tupi field through EWT, only about 3 years after discovery. This is a major accomplishment taking into consideration the logistic and technological challenges posted by this frontier area which is located about 300 km from the coast, in water depths of more than 2.000m. All this was only possible due to a dedicated technical effort and a great synergy among partners.
AAPG Search and Discover Article #90100©2009 AAPG International Conference and Exhibition 15-18 November 2009, Rio de Janeiro, Brazil