Gallango E. Oswaldo¹, Enrique Novoa¹, Asdrubal Bernal¹
(1) PDVSA-Intevep, Caracas, Venezuela

Abstract: The petroleum system in the Central Perija fold belt, Western Venezuela

The hydrocarbon system of the Maracaibo Basin has been the focus of numerous studies. However, the timing of hydrocarbon migration versus the timing of trap formation still remains as a key issue to solve in the Perija fold belt, western Maracaibo Basin. In this study, we show evidences of structures being filled by two oil migration events.

From Upper Cretaceous to present time, we have identified three major deformation periods in the area. The first one is of Campanian age, it is characterized by compression. The second period is characterized by extension of the area and took place from Upper Cretaceous to Upper Eocene. The third one is characterized by compression from Upper Eocene to Recent and it is responsible for the development of the major structures in the Central Perija fold belt.

Based on oil-oil and oil-source rock correlations and 1D basin modeling, we proposed two oil generation and migration events which are responsible for oil accumulation in the Central Perija foldbelt. The first event came from a kitchen of Upper Paleocene - Middle Miocene age located to the west-southwest of the study area. The second event was developed during Middle Miocene to Recent and it is located to the east of the same area.

The older kitchen is responsible for the accumulation found in the Upper Cretaceous traps located in the Central Perija fold belt. The younger kitchen is responsible for the fill of both Cretaceous and Tertiary reservoirs located to the eastern portion of the area.

AAPG Search and Discovery Article #90914©2000 AAPG Annual Convention, New Orleans, Louisiana