Assessment of the mineralogical composition of rocks is very important for a detailed lithological description of the section. This is especially important when the section is represented by rocks with a complex geological structure, such as heterogeneous limestones and dolomites, or sandy-argillaceous rocks with a multicomponent composition. In addition, to assess the effect of clay content on porosity, it is necessary to know the type of clay and its mineralogical composition. X-ray fluorescence analysis (XRF) of core samples is a direct method for studying the composition of rocks. However, the core is not available in all wells, not in the entire depth interval; therefore, the mineralogical composition of rocks is estimated based on the recorded data of pulsed neutron gamma ray spectrometric logging. Interpretation of these data is a rather complicated process and consists of primary processing of the recorded spectra and interpretation itself. The primary processing of the recorded spectra is carried out according to a certain technology, and the interpretation itself is based on the well-known geochemical model of oxides.
This article presents the results of the work of Bashkir State University on the data of primary processing and interpretation of spectra recorded by the device AINK-PL provided by VNIIA named by N.L. Dukhov. A quantitative interpretation of well logging data has been performed. Comparison of the results obtained in the work with the data of core analysis showed good agreement in the quantitative assessment of the mineral composition of rocks.
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