TRAUT, MARC W.
Occidental Oil and Gas Corp., Bakersfield, CA

Abstract: From Pre-Maturity to Extinction - the Life Cycle of Petroleum Systems

As a sequence of inter-related geologic elements and processes the history of a petroleum system can be classified in terms of a life cycle. Studies of a variety of petroleum systems from different settings around the world suggest that the position in the life cycle of a particular petroleum system is important when evaluating a basin or when generating a play or prospect. If the life cycle stages of a petroleum system are considered during the course of such an evaluation there is a greater chance that more quality exploration opportunities will be pursued.

The proposed life cycle stages for petroleum systems from beginning to end are: pre-maturity, maturity, destruction, and extinction.

A number of case studies of several petroleum systems from various life cycle stages are presented as examples. These include:

1. Silurian - Cambrian/Devonian/Triassic (!), from the Oued Mya Basin, Algeria;
2. Miocene - Sespe/Repetto/Pico (!), from the Ventura Basin, USA;
3. Miocene - Eocene/Paleogene(!), Talara Region, NW Peru;
4. Turonian (!), Northern Saharan Platform, Algeria;
5. Napo - Hollin Sandstone (.), Oriente Basin, Ecuador;
6. Silurian - Ordovician/Lower Devonian/Carboniferous(.), Tindouf Basin, Morocco - Algeria.

It is important to realize that the product of a petroleum system sought after by petroleum geoscientists - the commercial oil or gas field - is for the most part an ephemeral phenomenon in the sense of geologic time; the present day occurrence of these phenomena are the exception not the rule.

AAPG Search and Discovery Article #90928©1999 AAPG Annual Convention, San Antonio, Texas