Geochemical characteristics of aromatic hydrocarbons in crude oils from the Linnan Subsag, Shandong Province, China

Abundant aromatic fractions were detected in oils from the Linnan subsag, including aphthalenes, phenanthrenes, triaromatic steroids, biphenyl, fluorenes, dibenzothiophenes, dibenzofuranes, as well as some typical higher plant-sourced compounds, such as pyrene, benzopyrene, fluoranthene, chryaene, benzofluoranthrene, perylene and cadalene. Occurrences of biomarkers indicate that oils from the Linnan subsag are typical terrestrially genetic oils. Developed in the depositional environment is a strong reduction condition typical of brackish-saline lake. Thermal evolution has entered into the mature-high mature stage.