Publications on correlations among various properties of crude oils
reveal that the amount of asphaltene is a significant variable in all
cases. In particular, it has been repeatedly stated that generally an increase of
asphaltene contents is accompanied by; 1) a decrease of a content of
saturates and 2) an increase of a content of resins.
We have performed a detailed analysis of databases
for more than 390 world’s recovered (dead) crude oils. For saturates
and resins the analysis revealed a definite absence of
frequently assumed general
correlations with asphaltene content
and the existence of two distinct
types of world’s crude oils as classified with respect to their
asphaltene-based correlations. Moreover, these two types of oils
possess different correlations of asphaltene content with H/C
ratio (inverse measure of oil's aromaticity).