The effect of EOR technologies on the composition and properties of recovered crude oil was studied using crude oil from Usinskoye oil field (Republic Komi), which has high viscosity and high content of resins and asphaltenes. It is found that the Netrol system injection brings about an increase in the content of saturated hydrocarbons, asphaltenes and resins and a decrease in the content of aromatic hydrocarbons.  As a result of the NINKA system injection, the saturated hydrocarbon content of crude would also increase, while the asphaltene and resin content would decrease.  The application of the NINKA system in combination with thermal-steam treatment is found to cause an increase in the contents of saturated and aromatic hydrocarbons and reduction in the density of the studied crude oil.