摘要
对我国最大的咸水湖相盆地柴达木盆地西部南区40个原油样品进行了色-质分析,结合沉积环境分析其芳烃组成特征。萘、菲和三芳甾烷系列为优势组分,萘系列占总量的43%~59%,菲系列为12%~21%,三芳甾烷系列为6%~28%;芳烃成熟度参数和饱和烃成熟度参数C2920S/（20S＋20R）的相关性分析表明：甲基菲指数、MNR（2-甲基萘/1-甲基萘）和DNR（2,6＋2,7-二甲基萘/1,5-二甲基萘）等芳烃成熟度参数不适用于低成熟原油;而二苯并噻吩和三芳甾烷系列成熟度参数更适用于低成熟度咸水湖相原油,从而利用4,6-DMDBT/1,4-DMDBT比值得到了原油Rc值为0.59%~0.72%;三芴系列中,硫芴含量虽未出现高值,但氧芴的含量较低,反映出了该区咸水湖相厌氧环境,同时C26三芳甾烷的丰度较高也表明生油母质形成于还原性较强的半咸水、咸水环境中。
Based on GC-MS quantitative analysis of 40 crude oil samples from southwestern Qaidam Basin(which was one of the largest saline lacustrine basins in China) and in combination with the sediment environment,the aromatic hydrocarbon geochemical characteristics of oils were studied systematically.Among those constitutes,naphthalene(43 %~59%),phenanthrene(12%~21%) and taromatic-sterane series(6%~28%) were dominated in total aromatic hydrocarbon content.The analysis of aromatic hydrocarbon and saturate hydrocarbon maturity parameter C2920S/(20S+20R) shows that some aromatic hydrocarbon maturity parameters are not suitable for low-mature oils,such as MPI,MNR and DNR et al.Meanwhile,dibenzothiophene and taromatic-sterane series maturity parameters are more appropriate than before.By using the ratio of 4,6-DMDBT and 1,4-DMDBT,the Rc value is acquired among 0.59%~0.72%.Although the content of dibenzothiophene(DBT) is low,the dibenzofuran(DBF) content is even lower,which reflects the crude oils formed in saline lacustrine anaerobic environment.The high abundance of C26 triaromatic steroid also improve the source material is created from brackish water-saline water with strong reducibility.
出处
《石油天然气学报》
CAS
CSCD
北大核心
2011年第2期39-44,164,共6页
Journal of Oil and Gas Technology
基金
国家自然科学基金项目(40973041)
高等学校博士点基金(博导类)项目(20104220110001)
关键词
芳烃
地球化学特征
咸水湖相
原油
柴达木盆地
geochemical characteristics
aromatic hydrocarbon
crude oil
saline lacustrine
Qaidam Basin
