新疆石油地质 ›› 2009, Vol. 30 ›› Issue (2): 272-278.

• 讨论与争鸣 • 上一篇    下一篇

鄂尔多斯盆地深部地壳构造特征与油气成藏

张景廉1, 石兰亭1, 卫平生1, 张虎权1, 陈启林1, 李扬鉴2   

  1. 1.中国石油 勘探开发研究院 西北分院,兰州 730020;
    2.中国石化 地质矿山局 地质研究所 河北 涿州 072754
  • 收稿日期:2008-11-20 出版日期:2009-04-01 发布日期:2020-08-25
  • 作者简介:张景廉(1941-),男,江苏常熟人,研究员,地球化学, (Tel)0931-8686360(E-mail)zhang_n@petrochina.com.cn.

Deep Crustal Structure and Hydrocarbon Accumulation in Ordos Basin

ZHANG Jing-lian1, SHI Lan-ting1, WEI Ping-sheng1, ZHANG Hu-quan1, CHEN Qi-lin1, LI Yang-jian2   

  1. 1. Northwest Branch, Research Institute of Petroleum Exploration and Development, PetroChina, Lanzhou, Gansu 730020, China;
    2. Institute of Geology, Geology Mining Bureau, Sinopec, Zhuozhou, Hebei 072754, China
  • Received:2008-11-20 Online:2009-04-01 Published:2020-08-25

摘要: 根据鄂尔多斯盆地基底性质、基底断裂带分布、盆地巨厚白云岩分布,以及膏盐(特别是钾盐)和大量金属热液矿物,认为盆地曾有地幔流体的强烈活动。对鄂尔多斯盆地及西缘盆地(银川盆地、六盘山盆地)的深部地壳结构的研究表明,尽管鄂尔多斯盆地深部没有中地壳低速层,但银川盆地、六盘山盆地中地壳广泛发育低速高导层。地幔流体在银川盆地的中地壳低速高导层发生费托合成生成天然气;而在六盘山盆地的中地壳低速高导层发生费托合成生成石油。中生代晚期发生了强大的构造挤压推覆作用,中生界石油沥青的稀土元素分配模式、古生界天然气的碳、氢同位素特征均表明有地幔流体的参与。根据这一模式推测,鄂尔多斯盆地下古生界生物礁(白云岩为储集层,膏盐为盖层)是未来寻找大气田的主要靶区;盆地北部伊盟隆起的东胜地区深部中地壳有低速高导层,因此东胜砂岩铀矿下部可能有大油气田。最近,伊盟隆起中元古界钻遇天然气,表明了盆地北部基岩有良好的油气勘探前景。

关键词: 鄂尔多斯盆地, 油气成藏, 地幔流体, 中地壳, 低速高导层, 费托合成, 勘探靶区

Abstract: Based on the basement feature, basement faults distribution, thick dolomite occurrence, existence of gypsum-salt (especially sylvite) and abundant metal hydrothermal minerals in Ordos basin, it is indicated that there once existed intensive action of mantle fluid in this basin. The study of the deep crustal structure of Ordos basin and the western basins (Yinchuan basin and Liupanshan basin) shows that no mid-crust low velocity layer occurs in deep Ordos basin, but low velocity and high conductive layers widely appears in mid-crust of Yinchuan basin and Liupanshan basin, in which natural gas is generated from the Mantle fluid by Fischer-Tropsch synthesis in Yinchuan basin, while crude oil from it in Liupanshan basin. It is the tectonic compression nappe actions of Late Mesozoic that, on one hand, allow the natural gas in Yinchuan basin to migrate from west to east along unconformity (dominated by weathering crust) between the Ordovician and the Carboniferous (Permian) and structural fractural system and shape poors; on the other hand, allow the crude oil in Liupanshan basin to migrate toward the same direction along pseudoconformity between the Triassic and the Jurassic and form reservoirs. Also, Rujigou coal mine with low sulfur, low ash and premium anthracite is originated partly from the carbon-enriched mantle fluid in Yinchuan basin. the distribution pattern of rare-earth elements of Mesozoic petroleum pitch and the carbon and hydrogen isotope features of Paleozoic natural gas indicate the participation of such a deep crust mantle fluid. According to these, the reefs (dolomite as reservoir, gypsum-salt as cap rock) of Lower Paleozoic in Ordos basin are the main targets for further petroleum exploration; in deep Dongsheng area of Yimeng uplift in northern Ordos basin there exist mid-crust low velocity and high conductive layers, so large oil-gas field could be found below Dongsheng sandstone uranium deposit. At present, in Mid-Proterozoic of Yimeng uplift encountered natural gas by drilling (Jin-13 Well) and ignited successfully, foreshowing that there are bright prospects for petroleum exploration in basement rocks in northern Ordos basin.

Key words: Ordos basin, hydrocarbon accumulation, mantle fluid, mid-crust, low-velocity-high conductive layer, Fischer-Tropsch synthesis, exploration target

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