Abstract:
A significant quantity of hydrocarbons (including alkanes) is occluded in the skeleton of the asphaltene molecule. The hydrocarbons are probably remnants of the ''original oil'' which had been retained within the asphaltene matrix and protected from the secondary alteration processes that occurred subsequently in the oil reservoirs. In this work we report that oxidation of asphaltenes by stirring with 30%H2O2-HAc or NaIO4-NaH2PO4 can release nC7-soluble oxidized products, including the occluded hydrocarbons. Characterization of the nC7-soluble fractions of oxidized products can be applied to highlight some geochemical problems, such as in studies of oil-oil correlation, oil-source correlation and secondary alterations of oil reservoirs. It will be especially useful to recover the original geochemical information of some oil reservoirs heavily degraded by post-depositional processes.