Abstract: According to the steady-state catalytic hypothesis by Mango's about the origin of light hydrocarbons in crude oil and the relative plot between the percentage of the "parent" compounds (methylhexanes) in C7 and the abundance ratio of two kinds of the "daughter" compounds (1,1-and 1,3-dimethylcy-clopentanes; dimethylpentanes+3-ethypetane).The 141 kinds of crude oils from various tectonic units and layers of Tarim Basin are classified into two types (type A and B) and four sub-types.In order to testify the effectiveness of the classification and understand the factors which influence the classification of crude oils, trace elements, gas chromatograms of C₁₄⁺ compounds in saturate fractions, the compositions and distributions of biomarkers in various crude oils have been studied comprehensively.Because there are obvious differences in geochemical features and some distribution regularities in various crude oils, the new classification of crude oils are effective in Tarim Basin, especially to oil and gas regions with high maturity. The main factors which influence the classification of crude oils on light hydrocarbons may be the catalyst compositions controlled by depositional environments.In addition, the type of kerogen may have some influence on this classification, these results support Mango's viewpoints.

Key words: organic geochemistry, light hydrocarbon, Tarim Basin, crude oil, classification

摘要： 根据Mango提出原油中轻烃成因的假说--稳态催化成因,按“母体”(甲基己烷类)占C7化合物的百分数与两类“子体”(二甲基戊烷类+3-乙基戊烷;1,1和1,3-二甲基环戊烷类)丰度比的关系图,将塔里木盆地不同地区、层位的141个原油分成A、B两大类和四亚类。为了验证分类的有效性和研究影响分类的因素,对各类原油中微量元素、饱和烃的C₁₄⁺色谱、生标组成及其分布规律进行了综合研究。鉴于各类原油具明显的地化特征区别,且在地区、层位上有一定的规律性,证实根据Mango假说提出的新的原油轻烃分类方法在塔里木盆地是有效的,在高熟的油气区更有应用前景。研究成果支持Mango的观点,即影响轻烃分类的主要因素可能是受沉积环境控制的催化剂组成,此外干酪根类型等也可能有一定的影响。

关键词: 有机地球化学, 轻烃, 塔里木盆地