The source rocks and crude oils from the Qianjiang Formation (Eocene) in the Jiangban basin have been systematically studied in the present work. Supergene hydrocarboholds are characterized by (ⅰ) high alteration rat...The source rocks and crude oils from the Qianjiang Formation (Eocene) in the Jiangban basin have been systematically studied in the present work. Supergene hydrocarboholds are characterized by (ⅰ) high alteration ratio of soluble organic matter over organic carbon and middle ratio of hydrocarbon over organic carbon; (ⅱ) high content of non-hydrocarbon plus asphahene in extracts or crude oils; (ⅲ) sulfur-rich crude oils being an important immature crude oil; (ⅳ) alkane showing high content of phytane, gammacerane and marked even-carbon predominance or odd-carbon predominance; (ⅴ) aromatic biomarkers being distinctly classified into four groups; (ⅵ) pronounced evencarbon predominance in alkyl henzenes. In combination of all geochemical data. it is extrapolated that exploration of immature crude oil in hypersaline environment should be noticed.展开更多
文摘The source rocks and crude oils from the Qianjiang Formation (Eocene) in the Jiangban basin have been systematically studied in the present work. Supergene hydrocarboholds are characterized by (ⅰ) high alteration ratio of soluble organic matter over organic carbon and middle ratio of hydrocarbon over organic carbon; (ⅱ) high content of non-hydrocarbon plus asphahene in extracts or crude oils; (ⅲ) sulfur-rich crude oils being an important immature crude oil; (ⅳ) alkane showing high content of phytane, gammacerane and marked even-carbon predominance or odd-carbon predominance; (ⅴ) aromatic biomarkers being distinctly classified into four groups; (ⅵ) pronounced evencarbon predominance in alkyl henzenes. In combination of all geochemical data. it is extrapolated that exploration of immature crude oil in hypersaline environment should be noticed.
