液态正构烷烃系列、姥鲛烷、植烷碳同位素初步研究

A PRIMARY STUDY ON CARBON ISOTOPE OF N-ALKANE,PRISTANE AND PHYTANE IN CRUDE OIL

GC/C/MS 在线碳同位素分析技术,能够从微量样品(色谱量级)中获得丰富的单分子碳同位素组成信息。通过各种试验,确定了原油、氯仿沥青“A”饱和烃的 GC/C/MS分析条件、方法,并获得饱和烃中正构烷烃系列和姥鲛烷、植烷分子可靠的碳同位素组成数据。本文重点分析研究了鄂尔多斯盆地古、中生界原油,古生界源岩氯仿沥青“A”和热模拟产物——热解油中正构烷烃系列和姥鲛烷、植烷分子的碳同位素特征及分布模式,并进行了油源对比和油-油混源判别,得出了盆地石炭-二叠系和奥陶系顶部风化壳凝析油主要来自石炭-二叠系(尤其是煤)的新认识。

Using GC/C/MS online carbon isotope analytic technic,abundant imforma- tion about single molecular carbon isotope composition can be taken from micro-samples(chromatographical scale).Through conditional method expe- riment,GC/C/MS analysis conditions of oil,asphalt“A”saturated hydrocarbon can be defined,and reliable carbon isotope compositional data of n-alkane series of saturated hydrocarbon,as well as pritane and phytane can be obtain- ed.An analytical study centred on the characteristics and distribution modal of carbon isotopes of Pz.& Mz.oil,Pz.source rock chloroform asphalt“A”in Ordos basin and the product of thermal simulation i.e.n-alkane series,pri- tane and phytane in thermolysis oil,and oil source correlation and oil-oil mi- xing source differentiation,have been carried out.Finally,some new unders- tanding that the condensate oil of Carboniferous to Permian systems and the residue at the top of Ordovician system are mainly come from Carboniferous to Permian sediments(esp.coal Carbon iferous formations)is suggested.