Polycyclic aromatic hydrocarbon in solid reservoir bitumen from the central Sichuan Basin

Polycyclic aromatic hydrocarbons in solid bitumen from the central Sichuan Basin have been investigated. Several compounds including fluoranthene (Fl), pyrene (Py), benz[a]anthracene (BaA), chrysene (Chy), benzofluoranthenes (BFl), and benzopyrenes (BePy) are found to have enhanced concentrations in several samples. Abnormally high values of the Fl/(Fl + Py), BaA/(BaA + Chy), and BFl/(BFl + BPy) ratios are also observed. In addition, they have parent aromatic compounds that are considerably more abundant than their alkyl homologues. These features indicate that formation of the solid bitumen is probably related to abnormal heating, which may be induced by hydrothermal activity.