The article considers the problem related to the ambiguity of logging results, which is reflected in the reduction of the efficiency of certain interpretive methods, and as a consequence of oil and gas reservoirs omission. In this regard, the analysis of the results of gamma logging, spontaneous polarization methods, nuclear magnetic logging, were conducted. The received information of experimental researches of cores, has allowed establishing the reasons of distortion of radioactive and electric logging indications which considerably influence on size of radioactive and electric fields intensity. In addition, the efficiency of gamma-spectrometric method and nuclear magnetic resonance is substantiated. It is established that the matrix of rocks of Neogene sediments contains minerals of sulfides, oxides, which include iron, copper, aluminum. That determines the electronic conductivity of oil and gas saturated layers. Different from clarke, the contents of uranium, thorium and potassium were determined in the matrix of the above mentioned rocks according to the results of gamma spectrometry. These elements affect the value of the natural intensity of hydrocarbon-saturated rocks’ radioactive field. A method for determining the carke content of radioactive isotopes of uranium, thorium and potassium with the calculation of their ratio was developed to unambiguously assess the nature of the increased radioactivity of Neogene rocks. The results justify the use of the latest technological methods for gamma spectrometry and nuclear magnetic resonance in the allocation of productive rocks. Well research by NMR can be effectively performed with the help of NMLE-3 (nuclear magnetic logging equipment), and gamma spectrometry can be conducted with the help of SGSM-2