Research Article
Carbon and Hydrogen Isotopic Reversals in Highly Mature Coal-Derived Gases: A Case Study of Paleozoic Gases in the Southern Ordos Basin, China
Table 2
Relationship between maturity and carbon isotopic series in the Ordos Basin.
| Gas field | Source rock maturity | Carbon isotopic series | Detailed carbon isotopic series |
| Yan’an/South Jingbian | | Complete reversal | δ13C-CH4>δ13C-C2H6>δ13C-C3H8 | South Jingbian | | Partial reversal | δ13C-CH4>δ13C-C2H6<δ13C-C3H8 | South Sulige | | Partial reversal | δ13C-CH4<δ13C-C2H6>δ13C-C3H8 | North Sulige, Shenmu, and Daniudi | | Positive series | δ13C-CH4<δ13C-C2H6<δ13C-C3H8 |
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