伊犁盆地二叠系烃源岩地球化学特征及其地质意义

Geochemistry and geological signification of Permian source rocks in Yili Basin

虽然伊犁盆地在经历不同程度油气勘探后取得了一系列成果,但一直没有突破性进展,为此,在结合前人研究基础上,通过干酪根、饱和烃气相色谱、饱和烃质谱和碳同位素等分析技术,综合评价二叠系烃源岩有机质成熟度、有机质类型和沉积环境。研究表明:塔姆其萨依组烃源岩属于半深湖-深湖相沉积,具单一有机质来源,有机质类型以Ⅱ_1型为主,有机质成熟度适中,为区内较有利烃源岩;晓山萨依组烃源岩属于海陆交互相沉积,具多种有机质来源,有机质处于高成熟-过成熟阶段,为区内有利烃源岩。

Although a series of achievements has been obtained through different degrees of exploration, there remains no obvious breakthrough in oil-gas exploration in the Yili Basin, In such cases, combined with previous studies, a series of field geological sur- vey for hydrocarbon source rocks through collecting hydrocarbon source rock are carried out samples from typical geological sections, and comprehensively evaluated the maturity, type and depositional environment of Permian hydrocarbon source rocks by analyzing kerogen and measuring saturated hydrocarbons and carbon isotopes of source rocks with gas chromatography and mass spectrometer. The results indicated that source rocks in the Tamuqisayi Formation are semi-deep and deep lake deposits and their organic matter is mainly type II~ , with a single source and moderate maturity, being a more favorable source rock in the study area. While source rocks in the Xiaoshansayi Formation are paralic deposits, with a variety of organic sources and at a highly mature or overmature stage, being also a favorable source rock in the study area.