A Look at One of AAPG's Best and Brightest

From Start To Finish, People Made the Difference

Editor's note: These are the remarks made by Peter Vail as he accepted the Sidney Powers Memorial Medal, AAPG's highest honor, during the opening ceremonies of the recent annual meeting in Salt Lake City. Vail was honored for, among many highlights in his extraordinary career, his research, theory and work that linked stratigraphic interpretation with global sea level changes.

In this remarks, Vail offered a historical step-by-step review of the people and chapters that were involved in the landmark work.

Peter Vail accepts the Sidney Powers Memorial Medal from AAPG President Dan Smith while Executive Director Rick Fritz looks on during the Opening Session of the AAPG Annual Meeting in Salt Lake City.

First, I want to thank the AAPG committees and members who made it possible for me to receive this prestigious award. I also want to acknowledge and thank my colleagues who worked with me developing the concept and applications of sequence stratigraphy.

The roots of sequence stratigraphy started with a well log project in which John Sangree, Chuck Campbell and I correlated what we then called marker beds. We developed a series of stratal patterns including offlap, downlap and onlap.

I showed these patterns to a seismic interpreter named Paul Tucker, who told me you could see all these patterns on seismic data. He invited be to his office to see for myself. I was impressed and decided I should join the geophysical research department.

To everyone's surprise, in the early 1960s I did manage to transfer -- but I found I had joined a group of theoretical mathematicians and geophysicists. My group leader told me I had no future with the company. I just did not know enough mathematics. Fortunately, I had a good friend in the department name Frank Branisa, who labored long and diligently teaching me frequency spectra, band width and deconvolution.

During this period in the geophysical research department I learned of an Exxon well that was drilled on a structure basinward of a well that drilled a thick sand. The reflection that coincided with the sand top was traced basinward across the structure by the Exxon interpreter, where he predicted the sand to be present, but the well only found shale and silt and no sand.

Why did this happen? No one seemed to know.

I thought this would be a great project for me. Fortunately, management agreed.

After receiving the logs and seismic data I decided the only way to solve this problem was to do the paleontology for the reflection interval in both wells.

I managed to find Lou Stover, an Exxon paleontologist, who was available to work on the project. He found that the sand in the landward well was the same age as the correlative silt and shale on the basinward well with the structure.

To test the idea that the reflection was following the geologic time lines and not the top of the thick sand, I contacted my friend Frank Branisa to see if we could build an impedance analogue model and simulate a seismic section from it.

Exxon Research had an antilogue equilizer machine that would suit the project just fine. I built a geological impedance cross section between the two wells. Frank produced a synthetic seismic section using a pulse that matched the cycle breath on the seismic section. After this we made several more synthetic sections for different areas where we knew there were major facies changes from our early well log correlation work. Two examples are published in AAPG memoir 26 section 5 (Payton, 1977).

All the synthetic examples showed a reflection with a high amplitude on top of the sand. The high amplitude stepped down or up onto other reflections following the sand top as it changed facies. The amplitude of the original reflection decreases as it crossed the vacies change from sand to shale and silt, supporting the concept that seismic reflections follow the time synchronous stratal or bedding surfaces rather than the top of the sand formation.

Following this discovery, I gave many talks where I was commonly ridiculed. One senior geologist accused me of proposing that the reflections were bouncing off the backs of fossils. Another suggested that I was telling him that what he was teaching his students was wrong.

Time and experience prevailed, and now it is a well-accepted concept.

In the early 1960s, Exxon Research established a seismic stratigraphy section in the geology department with Mandy Touring as group leader. Other members were Howard Yorston an experienced seismic interpreter; John Sangree from the reservoir geology group; Mike Widmier geologist from Exxon operations; Bob Wilbur research geologist; Janet Teagarten, computer programmer who later became Janet Wilbur; and I. This diversified group worked well together until, regretfully, Mandy Touring became ill. I was then appointed section supervisor.

Our approach to research was to hold periodic meetings where the guidelines mainly proposed by John Sangree were to suggest worthwhile research ideas, assuming that we had unlimited funds. We would then discuss these ideas among ourselves and decide who would work on what.

I was especially interested in stratal patterns we had identified in our early well log correlation work, so I continued to work on this project on high quality seismic data from around the world.

What I observed first was that the widespread surfaces characterized by onlap were the most logical way to subdivide the section into major genetic intervals. As I observed these onlap surfaces and dated them with paleo information I found that sequences of the same ages tended to have the same onlap pattern in most basins around the world.

In order to convey this observation I drew a series of onlap charts that we converted into eustatic sea level charts. I also observed genetic sedimentary packages we came to call sequences, while working on a project in the North Sea.

Bob Mitchum returned from a one-year assignment in Midland, Texas, and upon his return to Exxon Research he joined our group and became involved in many of our major interpretation projects before becoming the major writer of AAPG Memoir 26.

It was in the mid-1970s when Jerry Baum, working on a thesis studying the Tertiary of the Atlantic coastal plain, recognized similar age sequences in his thesis area. When he graduated he applied for and received a position with our group.

In 1980 Rick Sarg joined our group. We then moved into a new building, and our seismic stratigraphy section became the seismic interpretation section, geophysical division, with Bob Todd as supervisor.

At this time I became a technical advisor and worked on a variety of projects and I worked with Jan Hardenbol and others to build the global cycle charts.

John Sangree and Mike Widmier worked on other sequence stratigraphic projects.

Seismic cycle configuration, called seismic facies, was interpreted in terms of sedimentary depositional units. Depositional sequences were recognized as sedimentary responses to cycles of relative falls and rises of sea level. Biostratigraphy was refined to give dates and depositional environments on a global basis.

Carlton Johnson joined our group with his computer applications to geology team. With these new people and skills, we concentrated on 3-D simulations of geology in addition to our seismic stratigraphy research.

After 30 years with Exxon and 15 years with Rice, I started my third career retirement with a wonderful kick-off party called the "Vail Fest," sponsored by Rice and Exxon. I received many wonderful compliments.

So my kids responded by saying: "If you're so smart why don't you find us some oil?"

That sounded good to me, so besides consulting I decided to invest in some oil and gas wells.

So far I've been on a learning curve -- I've learned that just because you find some oil or gas, it's not a discovery until you make money!

So far four of five wells have found oil or gas, and I do get a small amount of money from three of them. The fourth one is supposed to be a big money maker. I believe it is, but they are putting it on production now, so it will take a little more time before I know for sure. Recently I found out it's producing 200,000 million cubic feet of gas with oil from the occurrences with two more reservoir intervals above. I have a one-eighth interest in the well.

My kids changed their mind and decided I was using up my retirement money and pleaded with me to stop. My wife Carolyn backed me 100 percent, so I invested in another well. This came in at 600,000 cubic feet of gas with oil from the Tex-Mex interval with two more intervals to test. I only have a one-sixteenth interest in this well. I'm trying to bring in enough money to invest in oil and gas and still not spend my retirement money.

Again, I want to say how much this award means to me.

Thank you very much.