E. Chruściel1, T. Massalski3, K. W. Pałka1, J. Puchacewicz3, T. Zorski2
1 Faculty of Physics and Nuclear Techniques, University of Mining and Metallurgy, Krakow, Poland,
2 Faculty of Geology, Geophysics and Environmental Protection, University of Mining and Metallurgy, Krakow, Poland,
3 Well Logging Division of Geophysics Krakow, Polish Oil and Gas Company, Zielona Gora, Poland
Applications of the gamma-ray spectrometric method to the oil, gas and hard coal prospecting are presented. The use of a borehole spectrometer made it possible to determine in situ concentrations of the K, U and Th natural radioisotopes. The knowledge of K, U and Th concentrations gives an information which combined with other geophysical parameters such as: density, apparent photoelectric absorption cross section, Pe, and neutron porosity, constitutes a valuable tool for prospection of the investigated layers. The presented anomalies of uranium concentrations is of importance to determination of shale concentration in the rocks. The method, when applied in a hard coal deposit, made it possible to identify the coal seams and their thicknesses. The determined U, Th and K concentrations were used to calculate the calorific value, ash and carbon content in the coal.