Comparative analysis of composition and solubility of asphaltes from heavy oils of different oil fields

Composition and solubility of asphaltenes from various oil fields have been compared. The structural group abundance in the asphaltenes have been determined according to Fourier transform infrared spectra, while the contents of sulfur, vanadium, nickel, vanadyl complexes, and free stable radicals has been evaluated using various methods. The solubility of asphaltenes in the n-heptane-toluene system has been evaluated by spectrophotometric kinetic analysis. It has been determined that the relative content of condensed aromatic structures and carbonyl groups, as well as sulfur-containing structures and vanadyl complexes affect to various extents the solubility of asphaltenes. Effect of the composition of asphaltenes on their solubility is different in the case of conventional and heavy oils.