Super-deep, continental drilling in Germany



On September 8, 1990, Dr. Heinz Riesenhuber, the German Minister for Research and Technology, officially started the drilling of the super-deep borehole (Hauptbohrung) of the Federal Republic of Germany, known as the Konitinentales Tiefbohrprogramm der Bundesrepublik Deutschland (KTB). The borehole, situated in the Bavarian Oberpfalz near the village of Windischeschenbach, is expected to reach 10,000 m by the end of 1994. The eventual depth will depend on many variables, including cost; however, the hole may be extended even deeper if bottom- hole temperatures are less than 300°C. The Hauptbohrung was preceded by a pilot borehole (Vorbohrung), sited 200 m to the west, which was completed to a depth of slightly more than 4,000 m in April, 1989. The German government has allocated about 498 million DM (1 DM =˜US $0.67) for this project, of which slightly more than 25% has been spent on site preparation and the Vorbohrung. This report summarizes the KTB results and plans, in the context of the announcement by the National Science Foundation, the U.S. Department of Energy, and the U.S. Geological Survey [Eos, 1990] that U.S. scientists may submit proposals for collaborative research in the KTB by June 1, 1991.