Generation, migration and accumulation model for the marine oils in the Tarim Basin

被引：7

作者：

Li S.-M. ^{[1
]}

Pang X.-Q. ^{[1
]}

Yang H.-J. ^{[2
]}

Xiao Z.-Y. ^{[2
]}

Gu Q.-Y. ^{[2
]}

Zhang B.-S. ^{[2
]}

机构：

[1] State Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum

[2] Tarim Oilfield Company, PetroChina

来源：

Diqiu Kexue - Zhongguo Dizhi Daxue Xuebao/Earth Science - Journal of China University of Geosciences | 2010年 / 35卷 / 04期

关键词：

Biomarkers; Compound specific isotope; Fluid inclusion; Oil mixing model; Petroleum geology;

D O I：

10.3799/dqkx.2010.081

中图分类号：

学科分类号：

摘要：

The origin and accumulation mechanism of the marine oils in the Tarim basin has long been a disputed issue. Compound specific isotope, fluid inclusion technique and age-indicating biomarkers have been used in investigating hydrocarbons generation and migration in this study. It is observed that most of the oils in the Tazhong and Lunnan uplifts correspond well with the Middle-Upper Ordovician source rocks according to biomarkers, suggesting their good genetic relationship. However, the compound specific isotope of n-alkanes shows that the oils are primarily mixed oils from both the ε-O1 and the O2+3 strata, which is further proved by chemical components in fluid inclusions. It is predicated by δ13C of n-alkanes that, the ε-O1 genetic affinity oils mixed in the Tazhong oils range in 11%-100% (average of 45%), and about 11%-70% (average of 36%) in the Lunnan oils, which suggests that both the ε-O1 and the O2+3 are the main source intervals for the oils in the Tarim basin. A comprehensive study of migration fractionations of biomarkers and geological conditions shows that, No.1 fault and the associated faults played an essential role in hydrocarbons migration with several main charging points observed where strike slip faults cutting across the No.1 fault. However, lateral migration is an important pattern for the Lunnan oils. Several oil-mixing models are concluded including adjusting type with oil mixing during hydrocarbons re-migration and re-accumulation, multiple-charging type with hydrocarbons from different episodes, and primary type with oil mixed during secondary migration pathway even during primary migration. Our opinion of intensive oil mixing in the Tarim basin suggests great deep petroleum potential in the basin, and unraveling hydrocarbons-accumulation mechanism is significant for further petroleum exploration.

引用

页码：663 / 673

页数：10

共 34 条

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