Correlation of crude oils and oil components from reservoirs and source rocks using carbon isotopic compositions of individual n-alkanes in the Tazhong and Tabei Uplift of the Tarim Basin, China

► GC-IRMS was performed for crude oils and components in source and reservoir rocks. ► The δ13C values show the marine oils are derived from two types of source rocks. ► The δ13C values for oil components in reservoir rocks reveal source variations. ► δ13C values do not correlate with biomarker parameters for mature oils.