Print this pagePre-Salt Structural High in the Jequitinhonha Basin, Offshore Bahia State
The BM-J-2 Block, located in the central part of the Jequitinhonha Basin, offshore Bahia State, was acquired by Queiroz Galvão Óleo & Gás during the fourth ANP Brazilian Agency bidding in 2002. Jequitinhonha Basin is a divergent continental marginal basin that is counterpart of the west african south Gabon and north Congo basins. The block is entirely under water depths of 50 m. In this basin Petrobras drilled twenty five exploratory wells and found only one sub-comercial oil accumulation in the 1-BAS-37 well. The reservoirs are aptian age conglomerates and dolomites of the Mariricu Formation and fractured metasediments of the basement sealed by evaporites. Exploration activities in the area of BM-J-2 Block were held in the seventies and eighties, when five wildcats wells were drilled and good oil and gas shows were present in some wells, particularly in the Albian carbonates.
The integrated interpretation of 2D and 3D seismic data and gravimetric and
magnetometric
surveys resulted in mapping a huge structural high below the salt sequence. This External High is a structural feature strongly sought by Petrobras in the early phase of exploration of the eastern brazilian marginal basins. It has 4 km wide and 30 km long, NS direction and it is parallel to a internal graben, both developed during the Rift Fase. This structural framework was modified by a transversal fault, probably a transcurrent fault that segmented the structural high in its central part. Related to this External High, three structural prospects were mapped and they will be drilled in 2010 to test the pre-salt sequence. AAPG Search and Discover Article #90100©2009 AAPG International Conference and Exhibition 15-18 November 2009, Rio de Janeiro, Brazil