As the cumulative yield reaches 70% for Daqing decanted oil or 25% for Liaohe feed, the content of aromatics exceeds that of saturates and goes up rapidly while the saturates drop down by the same level.

• 大庆、辽河油浆分别在累积萃取收率达70%25和25%25后，窄馏分中的芳香分含量超过饱和分且迅速增加，而饱和分含量相应下降。