DALY, MICHAEL, BP Exploracion de Venezuela, Stockley Park, Middlesex, England, FELIPE AUDEMARD, Intevep, Miranda, Venezuela, and GUSTAVO VALDES, Petroleos de Venezuela, Caracas, Venezuela.

ABSTRACT: A Modern Regional Geological Analysis of Venezuela: Lessons from a Major New World Oil Province on Exploration in Mature Areas

Venezuela has produced some 44 billion bbl of oil since the early part of the century. As such, it represents one of the world's major oil producers and a mature petroleum province. However, major tracts of Venezuela's sedimentary basins remain underexplored, and large discoveries are still being made in new and old reservoir systems.

A regional geological analysis of Venezuela, focusing on basin evolution and sequence stratigraphy and incorporating data from the three national oil companies is presented. The analysis presents a regionally consistent tectonostratigraphic model capable of explaining the evolution of the Mesozoic and Cenozoic basins of Venezuela and placing the major reservoir facies in their regional tectonic and sequence stratigraphic context.

Four regional cross sections describe the stratigraphic and structural model. The model recognizes a Jurassic rifting event and inversion, succeeded by an Early Cretaceous passive margin. In western Venezuela, the Early Cretaceous passive subsidence is enhanced locally by extension related to the Colombian active margin.

Venezuela experienced a major change in the Campanian with the initial collision of the Caribbean arc, recorded by foreland structuring and widespread stratigraphic changes. From the Campanian onward, the tectonostratigraphic evolution can be modeled in terms of a progressive southeast-directed arc-continent collision and the migration of the associated foredeep and rift basins.

Within this tectonic framework, the major sequence stratigraphic units are identified and the reservoir distribution interpreted. This model provides a strong predictive tool to extrapolate reservoir systems into Venezuela's underexplored areas and to readdress its traditional areas.

AAPG Search and Discovery Article #90990©1993 AAPG International Conference and Exhibition, The Hague, Netherlands, October 17-20, 1993.