达尔其油田稠油生物降解有机地化特征

Organic geochemical characteristics of viscous crude oil biodegradation in Darqi oil field

方法从稠油生物降解宏观及微观特征入手，运用有机地球化学和稳定同位素分析，对达尔其油田稠油的地化特征及降解序列进行研究。目的分析稠油地化、成因特征及成熟度，为油田今后勘探指明方向。结果稠油宏观上具有饱和烃含量低，饱和烃／芳烃比值小的特点；微观上烷烃、芳烃色谱及生物标志物提供了稠油为两期混合油，且成熟度不高，降解程度较低。结论达尔其油田稠油属低─较低成熟油；稠油的降解程度可划分为三级；今后的勘探方向应以寻找稀油为主。

Method in view of the macro and micro characteristics of the viscous crude oilbiodegradation and the analysis of organic geochemistry and stable isotope, geochemicalcharacteristics and degradation sequence of the viscous crude oil in Darqi oil field are studied.Purpose To analyze the geochemical characteristics and contributing factor and maturity ofviscous crude oil in Darql in order to guide future exploration. Result Macroscopically, theviscous crude oil has the characteristics of low content of saturated hydrocarbon, small ratioof saturated hydrocarbon to aromatics. Microscopically, alkane, aromatics chromatographyand biological marker indicate that the viscous crude oil is a mixed oil of two periods, withlow maturity and low degree of degradation. Conclusion The viscous crude oil in Darqi oilfield falls to the category of low-fairly low maturity oil. The degradation of viscous crudeoil can be classified into three levels. It is suggested that future exploration be concentratedon light crude oil.