{"title":"2α-Methylhopane: Indicator for Oil–Source Correlation in the Pearl River Mouth Basin, China","authors":"Wanfeng Zhang, Xiangtao Jiang, Liling Pang, Xuanbo Gao, Shukui Zhu","doi":"10.1007/s10498-017-9317-7","DOIUrl":null,"url":null,"abstract":"<p>\nOil samples collected from the Pearl River Mouth Basin (PRMB) were analyzed using comprehensive two-dimensional gas chromatography coupled with time-of-flight mass spectrometry (GC?×?GC-TOFMS). High abundances of compounds in the 2α-methylhopane series were observed and accurately quantified. Although the 2α-methylhopane series can be a prominent biomarker in the oil and source rock samples, it has generally been used less than non-methylated hopanes. In this study, the 2α-MHI [C<sub>31</sub>2α-methylhopane?×?100/(C<sub>31</sub>2α-methylhopane?+?C<sub>30</sub>-αβ-hopane) (%)] ranges from 0.81 to 5.77% and 9.06 to 23.93% in Enping Formation- and Wenchang Formation-derived oils, respectively. The high abundance of the 2α-methylhopane series in Wenchang Formation-derived oils is attributed to anoxygenic phototrophs. The relevant 2α-methylhopane parameters showed correlations with C<sub>30</sub>-4-methyl steranes/∑C<sub>29</sub> steranes, Pr/Ph and bicadinane-T/C<sub>30</sub>-αβ-hopane. Furthermore, the 2α-methylhopane series are rich in middle-deep lacustrine environments as well as marine sedimentary environment. The results indicated that the 2α-methylhopane series could be used as effective biomarkers to distinguish oils derived from different source rocks, as well as to enlarge the PRMB biomarker assemblages, which is beneficial to the evaluation of petroleum resources.</p>","PeriodicalId":8102,"journal":{"name":"Aquatic Geochemistry","volume":"23 3","pages":"185 - 198"},"PeriodicalIF":1.7000,"publicationDate":"2017-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/s10498-017-9317-7","citationCount":"6","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Aquatic Geochemistry","FirstCategoryId":"89","ListUrlMain":"https://link.springer.com/article/10.1007/s10498-017-9317-7","RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"GEOCHEMISTRY & GEOPHYSICS","Score":null,"Total":0}
引用次数: 6
Abstract
Oil samples collected from the Pearl River Mouth Basin (PRMB) were analyzed using comprehensive two-dimensional gas chromatography coupled with time-of-flight mass spectrometry (GC?×?GC-TOFMS). High abundances of compounds in the 2α-methylhopane series were observed and accurately quantified. Although the 2α-methylhopane series can be a prominent biomarker in the oil and source rock samples, it has generally been used less than non-methylated hopanes. In this study, the 2α-MHI [C312α-methylhopane?×?100/(C312α-methylhopane?+?C30-αβ-hopane) (%)] ranges from 0.81 to 5.77% and 9.06 to 23.93% in Enping Formation- and Wenchang Formation-derived oils, respectively. The high abundance of the 2α-methylhopane series in Wenchang Formation-derived oils is attributed to anoxygenic phototrophs. The relevant 2α-methylhopane parameters showed correlations with C30-4-methyl steranes/∑C29 steranes, Pr/Ph and bicadinane-T/C30-αβ-hopane. Furthermore, the 2α-methylhopane series are rich in middle-deep lacustrine environments as well as marine sedimentary environment. The results indicated that the 2α-methylhopane series could be used as effective biomarkers to distinguish oils derived from different source rocks, as well as to enlarge the PRMB biomarker assemblages, which is beneficial to the evaluation of petroleum resources.
期刊介绍:
We publish original studies relating to the geochemistry of natural waters and their interactions with rocks and minerals under near Earth-surface conditions. Coverage includes theoretical, experimental, and modeling papers dealing with this subject area, as well as papers presenting observations of natural systems that stress major processes. The journal also presents `letter''-type papers for rapid publication and a limited number of review-type papers on topics of particularly broad interest or current major controversy.