成煤母质形成环境对热成因煤层气氢碳同位素的影响:不同气候环境的草本沼泽泥炭热模拟实验

发布时间：2018-05-21 19:42

  本文选题：泥炭 + 模拟实验　； 参考：《地球科学》2017年09期

【摘要】：煤层气的成因研究可以为煤层气勘探与开发提供科学依据,然而,煤层气的氢碳同位素组成受多种因素的影响,以前较多的研究是成气母质性质和成熟度对煤层气氢碳同位素的影响,对于成煤物质形成的气候环境对热解煤层气同位素的影响尚不清楚.热解模拟了高纬度寒冷干旱和低纬度热带湿润环境的草本泥炭,对热解烃类气体的氢碳同位素组成及其差异性进行了研究.研究结果表明:与低纬度热带湿润环境中形成的草本泥炭相比较,高纬度寒冷干旱环境的草本泥炭热解甲烷、乙烷和丙烷具有轻的氢同位素组成和重的碳同位素组成,并且从泥炭连续热解至Ro分别为2.5%、3.5%和5.5%时,甲烷、乙烷和丙烷δD值分别平均降低-17‰~-10‰、-32‰~-28‰和-25‰~-17‰,甲烷和乙烷δ13 C值分别平均升高2.9‰~3.6‰和0.9‰~1.1‰.认为这种同位素差异起因于气候环境对形成泥炭的植物氢碳同位素组成的影响.建立了高纬度寒冷干旱和低纬度热带湿润环境中形成的成煤有机质热解烃类气体氢碳同位素组成与Ro之间的关系式,同时也建立了烃类气体的碳和氢同位素之间的关系式.这些研究成果为不同气候环境下形成的成煤有机质生成的煤层气成因研究提供了科学依据.
[Abstract]:The genetic study of CBM can provide a scientific basis for the exploration and development of CBM. However, the hydrogen and carbon isotopic composition of CBM is affected by many factors. Many previous studies have focused on the effects of the properties and maturity of the gas-forming parent material on the hydrogen and carbon isotopes of coal-bed methane, and the influence of the climate environment formed by the coal-forming materials on the pyrolysis of coal-bed methane isotopes is still unclear. The herbaceous peat in high latitude cold arid and low latitude tropical humid environment was simulated by pyrolysis. The hydrogen and carbon isotopic composition and difference of pyrolytic hydrocarbon gases were studied. The results show that compared with herbaceous peat formed in low latitude tropical humid environment, the pyrolytic methane, ethane and propane of herbaceous peat in high latitude cold and dry environment have light hydrogen isotopic composition and heavy carbon isotopic composition. The 未 D values of methane, ethane and propane decreased by -17 鈥，

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