CAJ | 학술논문

银额盆地东部查干凹陷首次发现轻质低硫成熟原油，其饱和烃含量在90%以上，成熟度相当于镜煤反射率Ro1.0%左右，是生油高峰阶段的产物；原油全碳同位素δ13 C值－31.1‰。原油生物标志物中类异戊二烯含量较高，植烷与姥鲛烷均势；三环萜烷含量高于五环萜烷；含有较高的Ts C29、Ts C30重排藿烷、伽马蜡烷；藿烷中以C30藿烷为主，C32以上升藿烷含量极低；孕甾烷含量高；甾烷中以C29 甾烷为主，C27甾烷含量也较高，异胆甾烷含量高于胆甾烷；重排甾烷含量低；甾烷的含量与萜烷含量相当，是典型的湖相原油。已发现的天然气中甲烷含量达80%，为湿气。原油和源岩生物标志物组成特征分析对比表明下白垩统巴音戈壁组源岩是主要油源岩。生物标志物特征示原油具有一定的运移效应。
은액분지동부사간요함수차발현경질저류성숙원유，기포화경함량재90%이상，성숙도상당우경매반사솔Ro1.0%좌우，시생유고봉계단적산물；원유전탄동위소δ13 C치－31.1‰。원유생물표지물중류이무이희함량교고，식완여모교완균세；삼배첩완함량고우오배첩완；함유교고적Ts C29、Ts C30중배곽완、가마사완；곽완중이C30곽완위주，C32이상승곽완함량겁저；잉치완함량고；치완중이C29 치완위주，C27치완함량야교고，이담치완함량고우담치완；중배치완함량저；치완적함량여첩완함량상당，시전형적호상원유。이발현적천연기중갑완함량체80%，위습기。원유화원암생물표지물조성특정분석대비표명하백성통파음과벽조원암시주요유원암。생물표지물특정시원유구유일정적운이효응。
It is the first time that some crude oil has been discovered in the Chagan Sag, the eastern of the Yingen-Ejinaqi basin, NW China. The geochemical characterist ics of the oils (including oil sands) and source rock have been studied in this paper. The oils, in which saturated hydrocarbon accounts for more than 90%, belo ngs to maturated oils with a lower density and lower sulfur content at the gener aton peak stage (equal to Ro=1.0%±). The δ13C value of the whole o il is -31.1‰. The features of the biomarkers in the oils are as follows: relati vely high abundance of isoprenoidies, no preference between pristane and phytane ; the proportion of tricyclic terpanes over pentacyclic terpanes; relatively hig h amounts of Ts, C29Ts, C30-diahopane and gammacerane; the signific ant amounts of C30 hopane and much lower concentration of homohopanes (hig her than C32); high amounts of pregnanes; the significant proportion of C 29 sterane, relatively high abundance of C27 sterane, the proportion of isocholestane over cholestane; low concentration of diacholestane; equivalen t amounts between steranes and terpanes. The proportion of methane in the discov ered natural gas is up to 80%, reflecting that it belongs to wet gas.The oil-so urce correlation shows that the crude oils in Chagan Sag are generated from Lowe r Cretaceous Bayingebi Formation, and can be described as typical lacustrine oil s. Biomarkers reveal that the oil has a certain migration effect.