AAPG EXPLORER The way he is: Dietrich Welte continues to push the envelope on research and science. Welte from page 22 plants and animals, and chemical changes induced by burial and subsidence – stimulated my curiosity as a wouldbe-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 pr<strong>of</strong>essional 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 <strong>of</strong> 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 pr<strong>of</strong>essional 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 <strong>of</strong> source rocks and petroleum migration considerations in the strange world <strong>of</strong> the tropical jungle <strong>of</strong> the Niger Delta. Another would be having the chance to found, build up and guide a research Institute for <strong>Petroleum</strong> 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 <strong>of</strong> 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 <strong>of</strong> 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 “<strong>Petroleum</strong> Formation and Occurrence,” it was clear that the geochemical principles <strong>of</strong> source rock maturation, petroleum generation and many aspects <strong>of</strong> 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 <strong>of</strong> petroleum, in analogy to reservoir simulation, was the reconstruction <strong>of</strong> the temperature history <strong>of</strong> a given source rock. This triggered my interest in developing a research program for basin modeling. EXPLORER: What did you see as the goal <strong>of</strong> basin modeling? Welte: Modern geosciences live on the integration <strong>of</strong> 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 <strong>of</strong> complex subsurface geo-processes in a holistic manner. EXPLORER: What is most important for 24 MAY 2013 WWW.AAPG.ORG See Powers Winner, page 26
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