准噶尔盆地永1井油气来源及成藏模式分析

准噶尔盆地永1井侏罗系地层中存在几套地化特征完全不同的原油,油源分析认为其侏罗系西山窑组原油主要来自二叠系烃源岩、三工河组下部原油主要来自侏罗系烃源岩,而上部油砂的抽提物则具有上下2套原油的混合特征。侏罗系和二叠系是准噶尔盆地昌吉凹陷最主要的烃源岩,下二叠系烃源岩的主要生烃期在二叠纪末至侏罗纪早期,中二叠统烃源岩主要生烃期在三叠纪末期至早白垩纪,而侏罗系烃源岩的主要生烃期在第三纪以后。根据分析昌吉凹陷的构造演化后认为,西山窑组中的降解原油为侏罗纪末抬升剥蚀前形成的油藏,其正常原油油藏则在白垩系沉积后形成,而三工河组侏罗系原油则相对更晚形成。 

Analysis of oil-gas source and reservoir-formed model in Well Yong 1 of the Junggar Basin

Three types of crude oil with different geochemistry characterization occur in the Jurassic formation in Well Yong 1 of the Junggar Basin. Oil-source analysis indicates that the crude oil in Xishanyao Formation derived from the Permian source rocks, the crude oil in the lower Sangonghe Formation derived from the Jurassic source rocks, and the extract of the oil sand in the upper Sangonghe Formation is the mixture from the Jurassic source rocks and the Permian source rocks. The Permian and the Jurassic is the main source rocks in the Changji Depression of the Junggar Basin. The main generation stage of the Lower Permian is from the Late Permian to the Early Jurassic, the Middle Permian is from Late Tria-ssic to the Early Cretaceous period, and the Jurassic is after the Tertiary period. By studying the structure evolution of the Changji Depression, it is showed that degradation oil accumulated in Xishanyao Formation before the uplift at the end of Jurassic, the normal oil accumulated in Xishanyao Formation after the Cretaceous formation deposited, and the oil in Sangonghe Formation from Jurassic source rocks accumulated later.