准噶尔盆地西北缘侏罗系稠油形成机制分析

Genetic Mechanism of Jurassic Heavy Crude Oil in the Northwest Margin of Jugar Basin

为揭示准噶尔盆地西北缘侏罗系稠油形成机制,对稠油物理性质、族组分特征及其分布规律等分析,并结合该区侏罗系油气的运移和成藏过程的研究,恢复侏罗系原油的稠变历史。研究表明,侏罗系的稠油是二叠系的原生油气藏由于构造运动的破坏,油气发生二次运移,在运移过程发生氧化、生物降解等作用而稠化,在侏罗系超覆地层中聚集成藏,后期由于构造运动和地层水的水洗作用,形成了现在的稠油分布格局。

To reveal the genetic mechanism of Jurassic heavy crude oil in the northwest margin of Jugar Basin, the physical property, group composition and distribution rule of heavy crude oil are analyzed, and researches on hydrocarbon migrating and accumulating in the Jurassic period of this area are associated with, the heavy oil evolution is recovered. The studies manifest that primary oil gas pool in Permian Formation has been superposed and deformed by tectonic movements, thus the hydrocarbon has occurred second migration and accumulated into the overlap Jurassic Formation. In the process of the migration and accumulation, the hydrocarbon has become thicker in according with oxidation and biodegradation, and in the later stage through the virtue of tectonic movement and watered affection, the distribution of heavier crude oil has formed. Heavy oil is favorable for the formation of reservoir and the formation is a quite complicated procedure involving complex geological and geochemical function, therefore, the research on its genetic mechanism plays an important role in the exploration and exploitation.