It is demonstrated by mechanochemical conversion of high-molecular oil components that degradation of oil hydrocarbons by mechanical treatment in the presence of quartz is accompanied by formation of gaseous hydrocarbons. Upon mechanochemical treatment in the presence of quartz, asphaltene content decreases in Zuunbayan oil, but increases in Stolbovoi oil. Mechanical treatment reduces solid paraffin content in Stolbovoi oil, but increases it in Zuunbayan oil. Mechanochemical treatment of oil in the presence of quartz causes accumulation of poorly soluble organic substances consisting essentially of heteroatomic compounds on the surface of solid phase particles. Obtained data can be used to develop a mechanochemical oil treatment flow chart.