Abstract: Petroleum Systems of Western Venezuela

H. Passalacqua, O. Gallango, M. A. Capello, B. De Toni, R. Tocco, I. Truskowski, D. Loureiro

Integrating multidisciplinary information from western Venezuela Intevep, S.A. developed a comprehensive geological synthesis of the Maracaibo, Barinas and Apure basins which allow the description of 5 petroliferous systems with pods located within the Venezuelan borders: (1) Northeast of Maracaibo Basin, (2) Southwest of Maracaibo Basin, (3) Eastern Zulia, (4) Lara's Nappes and (5) Barinas Subbasin.

These systems comprise different structural styles: (1) basement tectonics, (2) thin-skin tectonics, (3) inversions, (4) triangular zones, (5) "flower and "pop-up" structures.

The main reservoirs in the region are the fractured Cretaceous limestones (K0 to K5), the Lower to Middle Eocene sandstones (T1 Misoa C and Misoa BC) and the Miocene sandstones of the Lagunillas Formation.

Three source rocks were identified: the principal one of Cretaceous age, marine origin and totally located in the Maracaibo Basin (K3-K4-K5, La Luna and Capacho formations) and two located south and southwest of the Maracaibo Basin, with organic material of continental origin, of Paleocene (K7-K8, Orocue and Marcelina formations) and Oligocene age (T4, Carbonera Formation).

Three expulsion periods were encountered: (a) Lower to Middle Eocene (52-40 Ma) and (b) Upper Eocene to Lower Miocene (40-21 Ma), with pods located in the northeast region of the Maracaibo Lake and (c) Lower Miocene to Holocene (21-0 Ma) with a pod located in the Maracaibo Lake.

AAPG Search and Discovery Article #90951©1996 AAPG International Conference and Exhibition, Caracas, Venezuela