UNSATURATED-HYDROCARBONS IN CRUDE OILS

The widespread occurrence of olefin-containing crude oils from various basins in the U.S.S.R. has been established. More than 900 crude oils were analysed by TLC of which nine (as crudes, and as separated olefin fractions) were analysed by gas chromatography, infra-red spectroscopy and H-1 NMR spectroscopy: two of the oils were similarly analysed by C-13 NMR. The carbon skeletons of the olefins, and coexisting saturates, correspond closely. The location of the double bonds in the olefin molecules is regarded as near statistical. A new concept of olefin generation in crude oils, by natural radiolytic dehydrogenation of saturated hydrocarbons is proposed. Different degrees of the subsequent natural thermocatalytic degradation of olefinic double bonds have been observed.