天然气中硫化氢硫同位素组成及沉积地球化学相

四川盆地天然气中普遍含有较高浓度的H₂S。作者在四川各时代气田采集气样近120个，分析了H₂S含量资料、探讨了天然气中H₂S浓度及其硫同位素组成与沉积地球化学相的相关性。研究表明，高硫化氢浓度和高δ₃₄s值均与碳酸盐-蒸发盐岩的分布有直接的成因联系。而与煤系、碎屑岩和非碳盐的海相地层形成的天然气中其硫化氢含量低、δ₃₄s值也低。据此，本文利用硫化氢硫同位素探讨天然气的来源及沉积环境。

Sulphur Isotopic Compositions of Hydrogen Sulphides in Natural Gases and the Sedimentary Geochemical Facies

High content of H₂S exists universally in the natural gas in Sichuan Basin. The authors collectednearly 120 gas samples of different geological times from Sichuan and analysed their H₂S contents,and inpart of the samples, the sulphur isotopic composition of hydrogen sulphides was also determined. Therelationship between the Hz S concentration,its sulphur isotopic composition in natural gases and the sed-imentary geochemical facies were discussed by combining with theH₂S content data of the other oil-andgas-bearing besins in China. The results showed that high H₂ conntrantion and heavy Saoncentrantions and heavy δ₃₄S clueshave a formative relation with the distribution of carbonate rocks and evaporite rocks, while the naturalgases generated incal fo rmatio n,ccastic rocks or non-carbonate marine sedimentary stratum have a lowH₂S oncentration and lighter δ₃₄S value. Accordingly, the source and sedimentary environment of nat-ural gases were discussed in this paper by means of the〔haracteristics of the sulphur isotope of hydrogens ulphi de s.