Structural Characterization of Arabian Crude Oils by ,13C N.M.R. Spectroscopy – A Comparative Study

Abstract

  In this paper 13C u.m.r. structural characterization oC Saudi Arabian light and extra light (Berri) crudes is reported and results are compared with our previously reported results on Arab heavy and Arab medium crudes. It is found that ash, sulphur, carbon, vanadium, nickle and viscosity increases from Arab. light to Arab heavy crudes. The yield of residue boiling above 454°C also increases Crom Arab light’ to Arab heavy crudes. It appears from these results that the differences in structure and composltlon of the aliphatic portion of these crudes are mainly of quantitative nature. These crudes are basically a mixture of similar aliphatic compounds but they are present in different concentrations in each crude. It is also observed that the Arab heavy contains a higher percentage oC aromatic carbons which have polycyclic aromatic rings in comparison to other crudes. This study has therefore, provided an important insight into the similarities and differences between the Courcommercial Saudi crude oils.