Abstract: Integrated Study Of Pato Area, Oficina Norte Trend, Eastern Basin, Venezuela

Roa, Elias; Hernandez, Lucila; Ramos, Alberto; Delgado, José - PDVSA and Berge, Timothy - Consultant

The Pato exploration area in the Oficina trend of the Eastern Venezuela Basin contains prospects in fault-bounded structural traps as well as stratigraphic potential in a newly-defined lowstand wedge play.

The basin has a tectonic history of transition from passive margin to a foreland basin. Structure and isopach maps and seismic and well log sections document periods of extension (16 to 9.2 MYBP) and compression (9.2 MYBP to recent) and show the eastward-shift of basin depocenter during the Miocene.

The five third-order sequences that comprise the Oficina formation were deposited during a second-order transgressive phase. Using biostratigraphy, these sequences have boundaries at. 25.5, 22, 17.5, 16.5, 15.5, and 10.5 MYBP. Maximum transgression occurred at 9.2 MYBP. The rate of coastal progradation was 1.3 m/My and the rate of shelfal aggradation was 112 m/My, calculated from pining points.

Integrated sequence stratigraphic interpretation using seismic, well logs, and core, has led to the identification of 3 lowstand wedge complexes that have excellent reservoir properties and thicken to the north. This model extends the reservoir potential of the play into deeper untested areas whereas the deltaic paradigm would condemn the northern area as reservoir-poor.

AAPG Search and Discovery Article #90933©1998 ABGP/AAPG International Conference and Exhibition, Rio de Janeiro, Brazil