地质通报2017，Vol.36Issue(4)：493-502,10.
准噶尔盆地西北缘超剥带轻质油的发现及意义
The discovery of light oil in the overlap-erosion zones of the northwestern Junggar Basin and its significance
摘要
Abstract
The heavy oil and oil sand constitute the primary target of exploration in the overlap-erosion zones of petroliferous basins.Here the authors present the first discovery of light oil in Mesozoic oil sands in the overlap-erosion zones of the northwestern Junggar Basin,report the basic characteristics and accumulation model of the light oil and investigate their implications for exploration.The results show that the light oil fluoresces yellowish green light and coexists with heavy oil with dark fluorescence.Reservoir sequential extraction of oil sands shows that the heavy oil (grain adsorbed and/or inclusion oils) charged reservoir before the light oil (pore free oils) and the oil sources were both from the Lower Permian Fengcheng Formation in the Mahu sag.Representatinve biomarker evidence includes Pr/Ph ＜ 1,gammacerane/C30 hopance=0.43～0.82 and tricyclic terpanes C20 ＜ C21 ＜ C23.Inorganic geochemical studies support this two-stage oil charging events.The MnO and FeO values of diagenetic calcites are 1％～1.5％ and ＞ 1.5％,respectively.Before the Cretaceous,the Fengcheng-sourced mature oil charged to the overlap-erosion zones of the study area and was biodegraded,and formed oil sand.Since the Cretaceous,the Fengcheng-sourced highly-mature and light oil has migrated from the Mahu sag to the overlap-erosion zones of the study area along transverse faults.As a result,the light oil accumulated mostly in the cross points of reverse and transverse faults.Accordingly,the zones along transverse faults are potential for light-oil exploration.Theexploration in overlap-erosion zones of petroliferous basins might not be merely confined to heavy oil and oil sand.Light oil and gas could accumulate if favorable reservoir forming conditions exist.关键词
超剥带/油砂/轻质油/横断裂/玛湖凹陷Key words
overlap-erosion zone/oil sand/light oil/transverse fault/Mahu sag分类
天文与地球科学引用本文复制引用
张景坤,周基贤,王海静,米巨磊,寇晨辉,王岩,周妮,曹剑..准噶尔盆地西北缘超剥带轻质油的发现及意义[J].地质通报,2017,36(4):493-502,10.基金项目
科技部国家油气重大专项《准噶尔前陆冲断带油气成藏关键勘探技术与新领域目标优选》(编号:2016ZX05003-005) （编号:2016ZX05003-005）
