Dietrich Welte is a pioneer of modern geoscience, co-author of the first comprehensive textbook on geochemical process-focused exploration, an outstanding academician and researcher, a leader in the development of basin and petroleum-system modeling.
He also is now the 2013 recipient of AAPG’s highest honor, the Sidney Powers Memorial Award.
Welte’s previous recognition from AAPG includes the President’s Award in 1966, the International Special Commendation Award in 2000, a Special Award in 2004 and the Distinguished Service Award in 2006.
A native of Würzburg, Germany, he has made a powerful, lifelong contribution to teaching the geosciences in Europe and to developing and applying scientific principles to exploration around the world.
EXPLORER: When did you know you were going to become a scientist?
Welte: Already as a schoolboy I was exposed to an atmosphere where science was part of daily conversations. Both of my parents had a scientific educational background. My mother had a Ph.D. in biology, which was very rare in the early 1920s for a woman.
My father was a geoscientist and university professor. Both of my parents died very early. My father was killed during the Second World War as a soldier and my mother died soon after the war from typhoid fever.
EXPLORER: Why did you study geoscience?
Welte: My interest for science was persistent, and when I started university in the city of Würzburg in Bavaria in 1952, I was undecided whether I should study chemistry or geology. Consequently, I tried as much as possible to devote time to both fields.
An organized student excursion in 1954 to the emerging post-war chemical industry in Frankfurt quickly brought the decision. I could not imagine spending part of my life as an industry chemist “in a little laboratory with unpleasant odors.”
From then on I focused on geology, and after my interim examination I moved from Würzburg to the University of Göttingen to take courses in sedimentology and mineralogy.
EXPLORER: Your biggest early influence was in modern geochemistry, a field you helped develop. What got you interested in geochemistry?
Welte: After the fall semester of 1956 I returned to the University of Würzburg and received a diploma in geology, equivalent to a master’s degree, in July 1957. During my stay in Göttingen I was exposed to geochemistry, which also suited my former inclination toward chemistry.
Winning a Fulbright scholarship brought me to the United States. There, I studied and worked as a graduate assistant in the geochemistry department of the Pennsylvania State University.
EXPLORER: And geochemistry was the start of your career?
Welte: An invitation by P.H. Abelson, at that time director of the Geophysical Laboratory in Washington, D.C., stimulated my interest in organic geochemistry.
The fate of organic substances in the Earth’s crust – the remnants of former plants and animals, and chemical changes induced by burial and subsidence – stimulated my curiosity as a would-be-chemist who was familiar with such geological phenomena as diagenesis and metamorphism.
Therefore, and because only very few geologists at that time were knowledgeable in organic chemistry, I decided to take a chance and try to make a professional career in this field.
EXPLORER: How did you get your first job in the industry, with Shell Oil?
Welte: In 1959, shortly before I received my Ph.D. in geology and geochemistry, I got an invitation to visit Shell International Oil Company, at that time called BIPM, in Den Haag, Netherlands.
A paper I had published the same year, about my very early mass spectrometric work at Penn State University using odd- and even-numbered carbon chain abundances to distinguish marine from limnic and terrestrial organic matter, had caught the attention of Shell. I was recruited by Shell in the same year.
EXPLORER: What would you have been if you weren’t a geoscientist?
Welte: Looking back, it is difficult for me to envisage a different professional career, other than to be a geoscientist.
If it would have been something else, I am pretty certain it would have been something connected with the natural sciences.
EXPLORER: What have been your most enjoyable jobs?
Welte: My first own and more or less autonomous research project in the early 1960s with Shell into the study of source rocks and petroleum migration considerations in the strange world of the tropical jungle of the Niger Delta.
Another would be having the chance to found, build up and guide a research Institute for Petroleum and Organic Geochemistry at the Nuclear Research Center (KFA) in Jülich, Germany, from 1975 to 2000.
That was an opportunity and a challenge at the same time. It was a dream come true for a geoscientist: the chance to combine a vast suite of modern analytical methods with geological concepts to investigate subsurface geo-processes in space and time.
A special, enjoyable period was the cooperation with the oil and gas company Canadian Hunter and its president, John Masters, in Calgary in the 1980s.
EXPLORER: You were an early and important pioneer in basin modeling. How did that interest develop?
Welte: During my time with Chevron in La Habra, Calif., in the 1960s I was exposed to reservoir simulation projects and the ongoing development of the black oil model.
In the 1970s and 1980s, when my friend and colleague (and AAPG Honorary member) Bernard Tissot and I had published our textbook “Petroleum Formation and Occurrence,” it was clear that the geochemical principles of source rock maturation, petroleum generation and many aspects of migration were reasonably well understood.
Then, looking at the so called Arrhenius equation, it was obvious the missing link to a numerical process simulation for the generation of petroleum, in analogy to reservoir simulation, was the reconstruction of the temperature history of a given source rock.
This triggered my interest in developing a research program for basin modeling.
EXPLORER: What did you see as the goal of basin modeling?
Welte: Modern geosciences live on the integration of formerly separate and sometimes even isolated fields like organic geochemistry, stratigraphy, sedimentology or other specific fields.
From the beginning, basin modeling aimed at integrating practically all the geoscientific disciplines with the ambitious goal to understand and quantify the chain of complex subsurface geo-processes in a holistic manner.
EXPLORER: What is most important for the future of oil and gas exploration and production?
Welte: It was not by accident that I named the basin modeling company I had founded Integrated Exploration Systems. Organic geochemistry was, and will be, one of the core disciplines in basin modeling, simply because organic molecules derived from formerly biological material have a fantastic memory.
Characteristic mixtures of hydrocarbon molecules and especially so-called biomarkers can tell us about their origin, source facies, maturity and, in certain instances, even about distances of migration.
This memory effect of organic molecules and the understanding of petroleum formation based on chemical kinetics was a game-changer in exploration. It opened the door from a static approach (find the trap) to a dynamic approach – that is, to understanding, reconstructing and quantifying the chain of processes from source to trap.
This, in turn, enforced a more focused collection of the all-important geological and geophysical subsurface data. In other words, this dynamic “petroleum systems modeling” approach became the modern blueprint for integration.
As a consequence of the numerical simulation of petroleum-related geo-processes in space and time, product prediction and risk assessment also gained a superior quality.
There is, in my eyes, no question that both exploration and production benefit alike from this integrated dynamic approach of what was originally called basin modeling. Product prediction and improved risk assessment also allow earlier and better planning of costly technical infrastructure and the use of financial resources.
EXPLORER: What is your view of the current activity in unconventional resource development?
Welte: Unconventional petroleum resources, like shale oil and shale gas, are part of the natural generation sequence of petroleum.
The current activity in unconventional resource development simply has shifted the emphasis from the end of the petroleum systems line, existing accumulations in classical reservoirs, to the beginning of the petroleum systems line – the hydrocarbons that have been retained in source rocks, or their organic-lean immediate neighborhood.
This new interest in mature source formations certainly gained a great momentum due to advances in directional drilling and hydraulic fracturing.
The mobilization of the hydrocarbons in mature source formations will stimulate additional geomechanical and geochemical research to better understand and improve production efficiency of shale oil and shale gas potential.
The integrated petroleum systems modeling described before is certainly an important and promising approach to further develop unconventional petroleum resources.
EXPLORER: What do you think about the current controversy over climate change?
Welte: The repeatedly propagated claim by the media and politics of a man-made climate change has, since the late 1980s, pushed aside the chance of an honest scientific debate in many Western countries.
Science organizations, inclusive of those in the geosciences, failed to bring this issue back to objectivity. The reasons for this failure are certainly diverse, but one of many reasons is the close association of certain scientific circles with politics and the media.
Geoscientists know that climate change is a normal, natural phenomenon, which occurred frequently during the Earth’s history. They also know that the paleoclimate record of millions of years does not support the hypothesis of a decisive influence of atmospheric CO2 on the Earth’s climate.
There is ample evidence that during the great ice ages in the Silurian and Carboniferous/Permian, atmospheric CO2 concentrations were much higher than today. We know from ice core data spanning several 100,000 years that it was the temperature that increased first, and that the rise in atmospheric CO2 was always lagging behind.
EXPLORER: How should geoscientists respond?
Welte: As geoscientists, we are aware of the fact that there are great uncertainties in understanding the details of the natural carbon cycle with respect to its different sources and sinks and the inherent flow dynamics and quantities.
Since the man-made CO2 amounts to approximately 6 percent of the global CO2 cycle, the impact of anthropogenic CO2 is still obscured by the uncertainties within the much bigger natural cycle.
It is high time that we, as geoscientists, raise our voice loudly and inform the public everywhere that the CO2 hypothesis, derived from purposely designed computer models, stands on weak ground and is far from being confirmed.
From my own experience I know that a critical review of the CO2 hypothesis, which is really necessary, only has a chance of success if it is made via a neutral, highly respected and scientifically competent platform.