Page 5 - The Petroleum System From Source to Trap

Preface ix

After presenting our work within Amoco, we Denver and offered me the opportunity to start a
were granted permission to share our concept with geochemical group at their research center in
the petroleum industry. Jim Momper and I Houston. Superior had just ac quired a new
organized a session on "New Ideas: Origin, kerogen maturity technique called "vitrinite
Migration, and Entrapment of Oil" for the 1972 reflectance" that was being used at the time only
AAPG Annual Convention in Denver, Colorado. by Shell and Tenneco. One of our biggest geochem­
Jack Williams presented a paper on "Characteriza­ ical limitations in those days was the lack of a
tion of oil types in the Williston basin" and I reliable way to measure thermal maturity of
followed with a paper on 'The Application of oil organic matter independent of kerogen type. I
correlation and source rock data to exploration in immediately recognized the potential of this new
the Williston basin." These papers were later and largely undeveloped technique, and after
published in the July 1974 AAPG Bulletin. Our considerable soul searching, I reluctantly left
approach of combining geochemical data into a Amoco in the fall of 1972 to begin a new ad venture.
complete geological framework formed the basis The petroleum system concept blends
for the petroleum system concept. Subsequent petroleum geology and geochemistry together in a
work by Perrodon, Meissner, and Ulmishek way that can substantially increase exploration
developed these ideas further and set the stage for success. It is a tool that has evolved during the past
Les Magoon's rigorous definition and application 25 years and will continue to be improved in the
of the petroleum system concept, beginning in future. This book makes our current state of
1986. knowledge available to every company involved in
Don Mathews, vice-president of the Superior the search for oil and gas, and we hope many will
Oil Company, heard my Williston basin paper in benefit from the ideas it contains.

Leslie B. Magoon company training classes, my experience with
exploration tools and techniques, such as paleon­
r the editors, this book has a two-fold tology, wireline logs, and geophysical data, grew
purpose-to describe the petroleum system quickly. In 1972 while in Denver, I attended the
Rnd to provide a mechanism for evaluating AAPG session on "New Ideas: Origin, Migration,
migration from the active source rock to the trap. and Entrapment of Oil." Wally Dow presented one
Wally and I developed the petroleum system for of two papers on source rock geochemistry of the
different reasons. Williston basin. Afterward, my colleagues at Shell
After graduation, I went to work for Shell Oil and I commented on how similar our approaches
Company in Los Angeles as an exploration and interpretations were for understanding the
geologist with emphasis on petroleum geochem­ distribution of hydrocarbons in the Williston basin.
istry. Although I lacked previous experience, At the time, I was working a little farther west in
because I had more chemistry than most geologists the Big Snowy trough so I could relate to their
I became immersed in source rock geochemistry to interpretation in the Williston basin. In late 1973, I
carry out my assignment, which was to participate was transferred to Shell Pectin and moved to
in the evaluation of the offshore lease sale area in Houston.
the Santa Barbara Channel. When I entered Shell, In 1974, I took a job with the USGS in Menlo
the company was taking the geochemical research Park, California, and had the opportunity to work
work of Phillippi from the laboratory to the field. on the Cook Inlet area in Alaska. My first assign­
Since little published literature was available, I ment was to evaluate the Federal OCS of Lower
relied mostly on company documents and a small Cook Inlet in preparation for an offshore lease sale.
cadre of Shell geologists and geochemists who In 1977, I was assigned to work on the North Slope
understood source rock geochemistry, such as John in the newly named National Petroleum Reserve in
T. Smith, Adrian Maaskant, Marian Downey, Alaska (NPRA) on an evaluation effort of the previ­
Archie Hood, and John Castano, all of whom ously named Naval Petroleum Reserve no. 4
willingly shared their knowledge with me. (NPR-4). With George Claypool, we carried out an
The source rock study of the Ventura basin­ in-depth source rock and migration study. Around
Santa Barbara Channel area was completed in 1968, 1981, my involvement in the A r ctic National
and I was transferred to Farmington, New Mexico, Wildlife Refuge (ANWR) began. During this time, I
then on to Denver in 1971 where I carried out was involved in both national resource assessments
similar source rock studies to support new plays in and the third was being organized.
both the southern and northern Rocky Mountain I had the privilege of participating on Leg 77 of
states. In addition to getting well site experience, I the Deep Sea Drilling Project (DSDP) in the
also had the opportunity to develop a play and Caribbean in December 1982. Here, I was able to
evaluate prospects that could be drilled. With reflect and read a great deal about petroleum