摘要
利用热模拟／在线同位素质谱和热模拟／气相色谱分析技术对鄂尔多斯盆地古生界气源岩和天然气烃组分组成和苯、甲苯碳同位素比值（＆13C）进行了测定。分析结果表明下古生界灰岩中的Ⅰ型和Ⅱ型有机质在高演化阶段生成的轻烃产物中同样具有芳烃含量高的特征，轻烃中本与甲苯δ13C值变化主要与有机质类型有关，鄂尔多斯盆地下古生界气源岩轻烃中苯与甲苯δ13C值-27‰。，上古生界约-22‰，上、下古生界气源岩中本与甲苯δ13C值相差较大，上古生界天然气δ13C苯和δ13C甲苯分别分布在-1864‰—－18.61‰和-23.71‰～－17．15‰之间，碳同位素偏重，下古生界天然气δ13C苯和δ13C甲苯分别分布在-28.99‰—-20.09‰和-26．59‰-22．03‰之间，碳同位素明显偏轻。根据轻烃组成和苯、甲苯的碳同位素比值进行了天然气气源岩的直接对比，结果表明下古生界天然气可能主要来源于下古生界气源岩。
The advanced analytic techniques of thermal stimulation/on-line stable carbon mass spectrum and thermal stimulation/gas chromatography have been used to determine the light hydrocarbon distribution and the δ13C ratio of benzene and toluene of source rock and natural gas. The analytic results indicate that Ⅰ、Ⅱ -type kerogen of lower Paleozoic limestone can generate more abundant benzene and touene of light hydrocarbon at the high stage of evolution. The 6l3C ratios of benzene and toluene of light hydrocarbon mainly vary with kerogen type and have little relation to the maturity. The δ13C ratios of benzene and toluene of light hydrocarbon of source rock between Lower Paleozoic and Upper Paleozoic in Erdos basin are about - 27‰, and -22‰,Vrespectively. It indicates that the δ13C ratios of benzene and toluene vary apparently. The δ13C ratios of benzene and toluene of natural gas between Lower Paleozoic and Upper Paleozoic are - 18. 64%,-18.61‰, and - 23. 71‰- 17.15‰, -28.99‰ -20.09%, and-26. 59‰ -22. 03‰ respectively. The direct correlation between source rock and natural gas has been taken according to the characteristics of light hydrocarbon distribution and δ13C ratios of benzene and toluene. Natural gas of Lower Paleozoic sources from source rock of Lower Paleozoic mainly.
出处
《沉积学报》
CAS
CSCD
北大核心
1999年第A12期820-824,共5页
Acta Sedimentologica Sinica
关键词
鄂尔多斯盆地
地球化学
天然气
古生界
气源对比
Ordos Basin thermal stimulation/on-line stable carbon mass spectrum thermal stimulation/gas caromatography benzene carbon isotope toluene' carbon isotope
