Title screen

[References: 7 tit.]

The data on the features of composition and properties of oils produced in 18 areas of the Nadym-Pur, Pur-Taz, Yamal and Gyda oil and gas regions of the north of Western Siberia are presented. Physical and chemical properties of oils (density, viscosity, content of oils, resins, and asphaltenes, IR spectral characteristics) are determined. A group of oils with a maximal content of oxygen-containing compounds reducing the surface tension at the 'oil-water' boundary when applying the EOR technologies using alkaline compositions has been selected. The predominance of acyclic compounds and biaromatic structures over triaromatic ones was observed for hydrocarbons (HC). The following hetero compounds have been identified: metalloporphyrins, dibenzofuran and its methyl and dimethyl derivatives, and trace amounts of dibenzothiophene and its homologues.