SUMMARY
The issues considered in the paper bear a direct relation to the disputable geo- chemical problems of the origin of oil – one of the main sources of modern energy gen- eration. Features of metal distribution in oils have not been studied yet, and natural classifications of oil fields of the Dnipro-Donets depression according to their contents have not been developed before. That stipulates the scientific novelty of the obtained results. Topicality and practical implications of the carried out studies are mainly in the fact the determined features of metal contents in oils and the classifications of deposits developed on their basis will favor the elaboration of a set of predictive criteria for industrial accumulations of hydrocarbons and scientific sub- stantiation of geological-economic, technological, and environmental estimation of their use. The objects of long-term studies include 36 oil fields: Bakhmatske; Prylutske; Krasnozaiarske; Kachalivske; Kremenivske; Karaikozovske; Korobochkynske; Kulychykhinske; Lipovodolynnske; Monastyrishchynske; Matlakhivske; Malosorochynske; Novomykolayivske; Perekopivske; Prokopenkivske; Radchenkovske; Raspashnovske; Sofiyivske; Sukhodolivske; Solontsivske; Solokhivske; Talalayivske; Trostianetske; Turutynske;Kharkovtsivske; Shchurynske; Yuryivske; Yaroshivske; Khukhrianske; Sahaidatske No 1; Sahaidatske No 13; Kybytsivske No 5; Ky- bytsivske No 51; Kybytsivske No 52; Kybytsivske No 56; and Kybytsivske No 1. They are located within the large tectonic structure of Eastern-European platform – Dnipro-Donets depression. The fields form the Dnipro-Donets oil and gas area of Ukraine. The paper is based on the results of studies of not less than 30 oil samples from each of the fields aimed at identification of metal content with the help of X-ray fluorescence analysis using energy-dispersion spectrometer «Sprut» SEF 01. Natural classification of oil fields in terms of content of each of the considered element have been developed basing on the results of cluster analyses implemented in terms of professional software platforms of versions STATISTICA 13.3 and IBM SPSS Statistics 22. The main scientific value of the obtained results is represented by the following: the development of natural classifications of oil fields of the Dnipro-Donets depression accord- ing to the results of cluster analysis of the content of metals, sulfur, and V/Ni ratio and substantiation of 5 new geochemical criteria for the division of fields formed by oils generated mostly by abiogenic or biogenic processes.