STUDY ON THE BIOMARKERS OF ASPHALTENE INCLUSIONS IN SEVERELY BIODEGRADED THICK OILS

The analysis on soluble organic matters from the crude oils of the Gudao Oilfield showed that the severe biodegradation have been taken place,and some biomarkers are not used to make oil—oil correlation and oil—source correlation.The ultrasonic wave technology was used to extract biomarkers from the asphaltene inclusions of the crude oils which are not susceptible to be biodegraded and compared with crude oils.The results showed that the steranes and terpanes of the asphaltene inclusions and the crude oil are very similar.Especially,the distributions of C₂₇,C₂₈,C₂₉ steranes are all "L" shaped in the crude oils and the asphaltene inclusions.Hence,the technology of extraction of asphaltene inclusions by ultrasonic wave can be successively applied to make oil—oil correlation and oil—source correlation of severely biodegraded crude oils.