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现代地质 ›› 2018, Vol. 32 ›› Issue (06): 1109-1124.DOI: 10.19657/j.geoscience.1000-8527.2018.06.01

• 石油地质学 • 上一篇    下一篇

东濮凹陷西斜坡盐湖相原油地球化学特征与油源分析

李蕾1,2(), 李素梅1,2(), 张洪安3, 徐田武3, 张云献3, 纪红1,2   

  1. 1.中国石油大学(北京) 资源与探测国家重点实验室,北京 102249
    2.中国石油大学(北京) 地球科学学院,北京 102249
    3.中国石化 中原油田分公司,河南 濮阳 457001
  • 收稿日期:2018-03-27 修回日期:2018-06-10 出版日期:2018-12-10 发布日期:2018-12-20
  • 通讯作者: 李素梅,女,教授,博士生导师,1968年出生,有机地球化学专业,主要从事油气与分子地球化学研究。Email: smli@cup.edu.cn
  • 作者简介:李 蕾,女,硕士研究生,1992年出生,地质资源与地质工程专业,主要从事油气与分子地球化学研究。Email:leili0515@163.com
  • 基金资助:
    国家自然科学基金项目(41473047);国家自然科学基金项目(41673055);国家重大科技专项(2016ZX05006-004)

Characteristics and Formation Mechanisms for the Saline Lacustrine Oil in the West Slope of the Dongpu Sag

LI Lei1,2(), LI Sumei1,2(), ZHANG Hongan3, XU Tianwu3, ZHANG Yunxian3, JI Hong1,2   

  1. 1. State Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum, Beijing 102249, China
    2. College of Geosciences, China University of Petroleum, Beijing 102249, China
    3. SINOPEC Zhongyuan Oilfield Company,Puyang, Henan 457001, China
  • Received:2018-03-27 Revised:2018-06-10 Online:2018-12-10 Published:2018-12-20

摘要:

东濮凹陷西斜坡油气成因与成藏机理复杂。采用色谱-质谱、傅立叶变换离子回旋共振质谱(ESI FT-ICR MS)、单体烃碳同位素等地球化学方法对东濮凹陷西斜坡原油特征及成因进行了剖析。共分出两种成因类型原油,第Ⅰ类为马寨地区原油,具有较低Pr/Ph(均值0.39)和C29-/C30-藿烷(均值0.33)、较高C35-/C34-藿烷(均值1.56)和二苯并噻吩/菲值(均值0.27)等强还原性、盐湖相原油特征,主要来自马寨次洼沙三下—沙四上亚段烃源岩;第Ⅱ类为胡庆-邢庄地区原油,盐湖相特征不及第Ⅰ类,主要来自柳屯、海通集洼陷埋深>3 000 m的沙三下—沙四上亚段烃源岩。ESI-FT ICR MS检测到深部原油含有热稳定性较低的硫化物,其硫同位素也偏高,指示TSR对深部油气的改造作用。观察到西斜坡地区烃源岩具有明显不同的两种热演化趋势,反映膏盐岩对烃源岩生烃演化显著的控制作用。西斜坡已发现原油大多具有低熟、早期成藏特征,与海通集、柳屯洼陷深部较高热演化程度烃源岩较为发育不太匹配,指示研究区具有潜在的深部油气勘探前景。

关键词: 东濮凹陷, 西斜坡, 盐湖相, 生物标志物, 油气成因类型, 油源对比, TSR

Abstract:

The hydrocarbons generation and migration style in the West Slope of the Dongpu Sag is rather complex. Geochemical methods including GC/MS, ESI FT-ICR MS and isotopic analysis, combined with geological methods are used to reveal hydrocarbon characteristics and genetic mechanisms for the saline lacustrine oils. The crude oils analyzed were subdivided into two oil families. Oil family-I is these oils in the Mazhai Tectonic Belt, which were characterized by relatively low ratios of Pr/Ph (mean 0.39) and C29-/C30-hopane (mean 0.33), and relatively high ratios of C35-/C34-hopane (mean 1.56) as well as dibenzothiophene/phenanthrene (mean 0.27). This family was primarily derived from the Es3L-Es4U mudstones/shales deposited under strong reduction and saline-water paleoenvironment in the Mazhai Sag. Oil family-Ⅱ is those oils in the Huqing-Xingzhuang area, featured by characteristics of a little different from the family-I, which has a relatively low ratio of C35-/C34-hopane and dibenzothiophene/phenanthrene relative to the oil family-I. The oils of family-Ⅱ are primarily derived from the Es3L-Es4U mudstones/shales in the Huqing Tectonic Belt and the adjacent Haitongqi Subsag with a burial depth >3,000 m according to oil-source rock correlation. It is the precursors and paleoenvironment which caused the differences between the oils. Abundant sulfur compounds with relatively low thermal stability were detected in the deep oils analyzed by ESI FT-ICR MS, accompanied by relatively high sulfur isotope of individual sulfur compounds. Both of the phenomenon suggest thermochemical sulfate reduction (TSR) experienced by the oils. Two thermal evolution trends were observed for the source rocks in the area suggesting affection of thick gypsum-salt rocks on the hydrocarbons generation of the source rocks. Most of the crude oils in the Huqing area are less mature, which is not coincided with the considerable amounts of deep source rocks developed in the area, suggesting a good potential of deep tight oil-gas exploration and exploitation in the area.

Key words: Dongpu Sag, the West Slope, saline lacustrine oil, biomarker, oil genetic type, oil-source rock correlation, TSR

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