PORTA, RODOLFO, STAN WHITE, and PETER SADLER, Astra-Repsol, Buenos Aires, Argentina

Abstract: Exploration of Thrusts Belts: Stratigraphic Controls and Structural Development of the Tala Thrust System, Eastern Venezuela Basin

The exploration of the external zone of the Serrania del Interior Thrust Belt, Eastern Venezuela Basin, since the mid 1980s has resulted on the discovery of the supergiant El Furrial field complex.The majority of these exploration efforts was and is focused on the Pirital thrust system located east of the oblique ramp known as Urica fault.Thin-skinned deformation is common with most oil and gas production from anticlinal traps involving Oligocene and Cretaceous sandstone reservoirs.

In contrast, west of the Urica lateral ramp, there has been little exploration conducted in the Tala thrust system. There, a major stratigraphic change is present in the Lower Miocene, which is reflected by a facies change from slope shally facies of Carapita Formation to the sandy shallow marine-deltaic facies of Capaya Formation. This deltaic unit is limited at its base and top by flooding events dated at the beginning and end of the Lower Miocene. Both flooding surfaces acted as decollement planes during south vergent compression, resulting in the development of a duplex involving competent deltaic sandstones of Capaya Formation. Recent seismic and well data confirms this structural-stratigraphic configuration and sheds light on the development of the Urica-Tala thrust system and its exploration.

AAPG Search and Discovery Article #90923@1999 International Conference and Exhibition, Birmingham, England