In 1989, Chevron Overseas Petroleum, Inc.,
developed a process to allow management to compare a wide variety of global
exploration opportunities on a uniform and consistent basis. Over the next
five years, the process evolved into an effective method to plan exploration
programs on a basis of value incorporating prospect ranking, budget allocation,
and technology management. The final product is a continuous process and
includes, within a single organizational unit, the integration of geologic
risk assessment, probabilistic distribution of prospect hydrocarbon volumes,
engineering development planning, and prospect economics.
The process is based on the concepts of the
play and hydrocarbon system. Other steps of the process (geologic risk
assessment, volumetric estimation, engineering support, economic evaluation,
and postdrill feedback) are considered extensions of fundamental knowledge
and understanding of the underlying geological, engineering, and fiscal
constraints imposed by these concepts. A foundation is set, describing
the geologic framework and the prospect in terms of the play concept-source,
reservoir, trap (including seal), and dynamics (timing/migration). The
information and data from this description become the basis for subsquent
steps in the process. Risk assessment assigns a probability of success
to each of these four elements of the play concept, and multiplication
1997. The American Association of Petroleum Geologists. All rights reserved.
received February 16, 1996; revised manuscript received September 26, 1996;
final acceptance February 4, 1997.
Overseas Petroleum, Inc., P.O. Box 5046, San Ramon, California 94583-0946.
acknowledge the champion of this process, M. W. Boyce, without whose continuing,
senior-management support this process would not have been possible. We
acknowledge the pioneering efforts of C. L. Aguilera, G. A. Demaison, E.
J. Durrer, F. R. Johnson, W. E. Perkins, J. L. Reich, and R. A. Seltzer,
who established the framework for the process in its early stages. We also
acknowledge the efforts to refine, document, and teach the process during
the later stages by S. D. Adams, A. O. Akinpelu, G. A. Ankenbauer,
G. L. Bliss,
T. J. Humphrey, E. McLean, and D. B. Wallem. Finally, we acknowledge all
the people who, over the past several decades, have championed such a process,
but fell victim to deaf ears because of high oil prices or dumb luck. These
people provided the well-founded basis for the theoretical and practical
application of evaluation principles. We also wish to extend special thanks
to Gerard Demaison and Erwin Durrer for their continuous support, guidance,