准噶尔盆地南缘安集海河组烃源特征及成藏条件

通过应用地球化学分析、油源对比及盆地模拟等手段对准噶尔盆地南缘古近系安集海河组烃源岩进行了评价,认为该区为一套以Ⅱ型干酪根为主的中等丰度烃源岩,生烃的门限深度为3500 m,时间是8 Ma±。第三系的油藏与其具有密切关系,同时侏罗系煤系烃源岩也为第三系的生油做出了贡献。造成该套烃源岩评价较低的主要原因是地层内发育的异常高压降低了烃源岩的成熟度指标,但由于长期构造挤压的"力化学"作用还是促进了烃源岩的生排烃,并且位于向斜部位的烃源岩其埋深大多超过生烃门限深度,也可以生成大量油气,因此认为还是有效的烃源岩。其生排烃时间与该区构造大规模形成时间相匹配,在背斜形成过程中,伴随着异常压力的产生、平衡,最终促进了油气在背斜核部聚集成藏。有利的勘探区是南缘中段的第二排、第三排构造古近系的安集海河组以及新近系的沙湾组储层。

The Anjihaihe source rock characteristics and hydrocarbon accumulation condition in the southern edge of Junggar Basin

By Geochemistry analyzing,oil source comparing and basin modeling,evaluated the Paleogene Anjihaihe source rock in the Southern Junggar Basin,which is Ⅱ Kerogen type and middle rich source rock,the limited depth of generate hydrocarbon is 3500 meters,and the time is 8 Ma.the oil stored in Tertiary formation derived from it and mixed with Jurassic Coal's oil.The main reason of lowly appraising to it is the overpressure depress the maturation parameter of source rock,but the long and strong tectonic compression may promote the hydrocarbon generated from source rock,and the bury depth of source rock lay in the syncline great than the limited depth,which can generate lots of hydrocarbon,so this source rock is effective.The time of hvdrocarbon generated and expelled suited with the forming of anticline,and in the course of anticline forming,with the producing and balancing of overpressure,the oil gradually accumulated on the top of the anticline.The more advantaged exploration areas are the first and second structure belt,the main intended formation are Anjihaihe set of Paleogene and Shawan set of Neogene.