石油与天然气地质 ›› 2000, Vol. 21 ›› Issue (3): 249-251.doi: 10.11743/ogg20000313

• 油气空间 • 上一篇    下一篇

查干凹陷原油地球化学特征与油源对比

林卫东   

  1. 中国石油天然气集团公司西北地质研究所,甘肃兰州730020
  • 收稿日期:1999-11-09 出版日期:2000-09-25 发布日期:2012-01-16

GEOCHEMICAL CHARACTERISTICS OF CRUDE OIL AND CORRELATION OF OIL SOURCE IN CHAGAN SAG

Lin Weidong   

  1. Northwest Institute of Geology, CNPS, Lanzhou
  • Received:1999-11-09 Online:2000-09-25 Published:2012-01-16

PDF (PC)

926

被引次数

45

摘要：

查干凹陷是一个中、新生代断陷盆地,其原油属低密度、低粘度、低硫中蜡轻质油,具饱和烃含量高(占原油的80%～90%)、C27甾烷丰富等特点。该凹陷发育下白垩统巴音戈壁组二段和苏红图组一段两套烃源岩。甾烷ααα(20R)C27/C29比值,类异戊二烯烷烃Pr/Ph,Pr/nC17比值及碳同位素曲线特征均显示原油与巴音戈壁组二段的白云质泥岩具有较好的亲缘关系,而与苏红图组一段深灰色泥岩亲缘关系不明显。因此,查干凹陷的原油主要来自下白垩统巴音戈壁组二段的白云质泥岩。

关键词: 原油, 烃源岩, 地球化学特征, 油源对比, 查干凹陷

Abstract:

Chagan Sag is a Meso-Cenozoic fault depression.The crude oil in it is of low density,low viscosity,low sulfur content,mid paraffin and lightweight oil characterized by high saturated hydrocarbon contents(80%～90%)and rich C27 sterane.The second member of Bayingebi Formation(K1b2)and the first member of Suhongtu Formation(K1s1)of the Lower Cretaceous are potential source rocks of the sag.The ratio of ααα(20R)C27/C29 and ααα(20R)C28/C29 of crude oil and the extract from oil bearing sand is 0.39～0.75 and 0.4～0.7 respectively.The ratio of Pr/Ph and Pr/nC 17 is 0.79～0.94 and 0.83～1.34.The carbon isotopic characteristic curve of crude oil is more similar to dolomitic mudstone of K1b2 and differs from the dark grey mudstone of K1s1.Synthetical correlation shows that the crude oil is mainly derived from the second member of Bayingebi Formation(K1b2)dolomitic mudstane.

Key words: crude oil, source rock, geochemical characteristics, oil source correlation, chagan sag

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