Organic geochemistry of crude oils from the Intisar oil field (East Sirte Basin, Libya)

Four crude oil samples from the oil fields Intisar A, Intisar D and Intisar E (Sirte Basin, Libya) were investigated in order to define depositional environment, lithology, thermal maturity and geologic age of the corresponding source rocks. Saturated biomarkers (n-alkanes, isoprenoids, steranes and triterpanes) were determined using gas chromatography – mass spectrometry (GC–MS) and gas chromatography – mass spectrometry – mass spectrometry (GC–MS–MS). Aromatic hydrocarbons (phenanthrene, methylphenanthrenes, methyl-dibenzothiophenes and trimethyl-naphtalenes) were analyzed by GC–MS.