塔里木原油含硫化合物的地球化学意义

塔里木盆地30余个代表性原油芳烃组分的色质和色谱－原子发射光谱分析资料表明,不同成因原油的含硫化合物含量和分布明显不同。与陆相原油相比,海相原油以高二苯并噻吩系列(>20%)、高DBT/P(>0.35)为特征,其中,塔中局限性海湾相原油以这两参数值更高而与塔北台地相原油形成区别；在二苯并噻吩系列内分布上,它们的DBT少而DMDBT丰富,反映出成油母质沉积环境性质的差别。来源于不同岩性源岩的原油中苯并噻吩系列相对于二苯并噻吩系列的含量不同,在碳酸盐岩原油中较高。 

GEOCHEMICAL SIGNIFICANCE OF ORGANIC SULFUR COMPOUNDS IN THE TARIM OILS

Aromatic fraction in more than 30 representative oils from the Tarim Basin are analyzed using GC/MS and gas chromatography with atomic emission detector(GC/AED).The analytical data shows that various kinds of oils are significantly different in concentration and distribution of organic sulfur compounds.Compared with the terrestrical oils,the marine oils are characterized by high amount of dibenzothiophenes(20%)and high dibenzothiophene/phenanthrene ratio(>0.35).By their higher values of these two para meters,Tazhong restricted bay(lagoon)oils can be distinguished from Tabei marine platform oils.These marine oils are poor in dibenzothiophene(DBT)compared to dimethylated homologs(DBDBT),reflecting the difference in oringinal organic matter and depositional enviroment.It is noted that the abundance benzothiophenes(BTs)relative to dibenzothiophenes(DBTs)varies in oils from different source rock lithologies,with oils derived from carbonate having higher value.MDR,a maturity indicator based on dibenzthiophenes in oils,is affected by mineral matrices,with coal derived oil having anomalous high value,and MDR₁ and MDR_2,3 are related to depositional environment and organic matter type.