辽东湾拗陷南部古近系原油芳烃地球化学特征与油源分析

研究辽东湾拗陷南部旅大地区古近系原油芳烃地球化学特征,为油气成因研究及油源判别提供参考.以LD27-2和LD22-1油田等为例,对明化镇组、馆陶组、东营组和沙河街组原油或岩屑抽提物进行系统的芳烃色谱-质谱分析,共检测出12个系列169种化合物,提取能够指示生源、沉积环境、成熟度和油源的地球化学参数并进行系统分析.结果表...

Analysis on geochemical characteristics of aromatic hydrocarbon and oil source of Paleogene crude oil in the southern Liaodong Bay Depression,China

The geochemical characteristics of aromatic hydrocarbons in Paleogene crude oils in Lüda area,southern Liaodong Bay Depression are studied in order to provide references for the verification of hydrocarbon genesis and the identification of oil source.Taking LD27-2 and LD22-1 oil fields as examples,the aromatics chromatography-mass spectrometry(GC-MS)analysis of crude oil or rock debris from Minghuazhen Formation,Guantao Formation,Dongying Formation and Shahejie Formation is carried out.A total of 12 series of 169 compounds are detected,and the geochemical parameters reflected the source,sedimentary environment,maturity and oil source are extracted and analyzed systematically.The results show that the sedimentary environment of parent material of crude oil in Luda area is mainly sulfur-poor lacustrine facies and common lacustrine facies with a weak oxidation-reduction environment.The higher plant input is obvious in the E₃d³ source rock,and the lower algae contribution is obvious in the E₂s³ source rock.Parameters of alkyl naphthalene,dibenzothiophene and phenanthrene series compounds indicate that the crude oil in this area belongs to mature crude oil,with the mature stage of vitrinite reflectance of 0.7%~0.8%.The C₂₈20S-C₂₇20R-C₂₈20R of the E₃d³ is mostly inverted“V”shaped,while the C₂₈20S-C₂720R-C₂₈20R of the E₂s³ is mostly“V”shaped.According to the C₂₆-C₂₇-C₂₈ triarylsterane assemblage parameters and carbon isotopic composition of crude oil,it is considered that the crude oil in Minghuazhen Formation and Guantao Formation is mainly provided by the source rocks of the 3rd member of Shahejie Formation.