中文摘要：

用采自中国国内25个油区的772个原油轻烃分析数据,结合其中338个样品的饱和烃GC/MS分析数据,就原油正、异庚烷值与烃源岩干酪根类型的关系以及与C29甾20S/（20S＋20R）成熟度参数的相关性,对影响参数值发生异常变化的因素等作了研讨。研究认为,正、异庚烷值确实与母源干酪根类型有关,但相关关系与Thompson的图版有所差别,研究中国陆相原油时不宜直接引用;原油次生蚀变和混源是使原油正、异庚烷值发生异常变化的重要因素,在用正、异庚烷值作研究时必须备加注意;正、异庚烷值标示原油成熟度的范围大于C29甾20S/（20S＋20R）所能标示的;落入Thompson图版＂Biodegraded＂区域的油样可能有3类：原生的未熟油,已遭蚀变的原油和成熟度不同的混源油,对于未落入该区域内的生物降解油,认为油藏存在二次注入的可能性。图6表2参26

英文摘要：

The data of light hydrocarbon from 772 oil samples in 25 oilfields,with GC/MS data from 338 saturated hydrocarbon samples were used to discuss the relationship among kerogen type,heptane value,isoheptane value and C29sterane 20S/（20S＋20R） ratio.The effect factors for the abnormal change of these parameters were studied.Although the heptane value and isoheptane value are related to kerogen type,the correlation is different from that in Thompson figure,so the correlation in the figure can not be directly used in research of land facies oil in China.Consideration should be taken when using the heptane value and isoheptane value because the secondary alteration and mixture of oil source are the main factors leading to the abnormal change of the heptane value and isoheptane value.The heptane and isoheptane values have larger maturity range than that of C29sterane 20S/（20S＋20R）.There are three types of oil samples（original immature oil,alteration oil and mixed source oil with different maturity） that may fall into the ＂Biodegradation＂ area of the Thompson figure.For the biodegraded oil out of the Thompson figure,the reservoir may have secondary injection possibility.