渤海湾盆地临清坳陷东部未熟—低熟油成因探讨

A Study on Immature Oil′s Genesis in Eastern Linqing Depression of Bohai Bay Basin

通过对渤海湾盆地临清坳陷东部未熟—低熟油的形成条件及形成机制探讨,总结出沙一段和沙三段的微咸水—咸水介质环境、丰富硫细菌和含硫化合物为临清坳陷东部未熟—低熟油气形成提供了有利条件,证实该区未熟—低熟油气形成是低活化能的富氢腐泥组分受到硫细菌早期低温降解作用的结果,明确该区未熟—低熟烃源岩硫细菌降解的有机质早期生烃阶段的Tmax值为400~435℃,RO值为0.2%~0.5%,生油高峰Tmax值为420℃,RO值为0.35%左右。

The study of the forming condition and mechanism of immature oil in eastern Linqing depression reveals that brackish water-brine,abundant sulfur bacteria and sulfocompounds provided favorable conditions for the formation of the immature oil.Immature oil was the result of hydrogen-rich sapropel of lower activation energy degraded by sulfur bacteria.Tmax and Ro of the early hydrocarbon generation of organic matter were 400~435℃ and 0.2%~0.5% respectively,and their values for peak hydrocarbon generaion are 420...