期刊名称：Geological Survey of Denmark and Greenland Bulletin
印刷版ISSN：1604-8156
出版年度：2013
卷号：28
页码：61-64
语种：English
出版社：De Nationale Geologiske Undersoegelser for Danmark og Groenland
摘要：Gamma-ray logs are widely used as a lithology indicator inwells as part of standard petrophysical interpretations. Incored wells, gamma-ray logs should always be calibrated tothe lithology in order to correct the petrophysical model.Gamma radiation is emitted from three elements, K, Th andU (potassium, thorium and uranium) which occur in mineralssuch as feldspar, mica, glauconite, clay minerals, zircon,titanite and apatite as well as in organic complexes. Organicrichmudstones usually have high gamma-radiation valuesand quartz-rich sandstones low values. In many places, upward-coarseningsuccessions are recognisable from the gammalog. The gamma log records the sum of radiation fromK, Th and U, and their relative contributions are measuredin a spectral gamma-ray log. The present case study focuseson spectral gamma-ray characterisation of the deltaic Atane Formation which shows well-developed, upward-coarseningdelta-front deposits in outcrops (Fig. 1C).
