石油学报 ›› 2005, Vol. 26 ›› Issue (S1): 92-96,101.DOI: 10.7623/syxb2005S1019

• 论文 • 上一篇    下一篇

柴达木盆地西部第三系盐湖相烃源岩特征与成烃演化

彭德华1,2, 苏爱国3, 朱扬明4, 郭静2, 张冰清2   

  1. 1. 中国科学院广州地球化学研究所 广东广州 510640;
    2. 中国石油青海油田分公司研究院 甘肃敦煌 736202;
    3. 中国石油勘探开发研究院 北京 100083;
    4. 浙江大学地球科学系 浙江杭州 310027
  • 收稿日期:2004-09-20 出版日期:2005-12-25 发布日期:2013-11-19
  • 作者简介:彭德华,男,1961年9月生,1982年毕业于西南石油学院,现为中国石油青海油田分公司研究院高级工程师,中国科学院广州地球化 学研究所在读博士研究生,长期从事石油地质综合研究.E-mail:dhpqh@petrochina.com.cn
  • 基金资助:

    中国石油天然气集团公司"十五"重点科技攻关项目"主要含油气盆地油气资源评价"部分成果.

Evolutionary process of hydrocarbon generation and characteristics of source rocks of the Tertiary salt lacustrine facies in the west of Qaidam Basin

PENG De-hua1,2, SU Ai-guo3, ZHU Yang-ming4, GUO Jing2, ZHANG Bing-qing2   

  1. 1. Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China;
    2. Research Institute of Petroleum Exploration and Development, Qinghai Oilfield Company, CNPC, Dunhuang 736202, China;
    3. Research Institute of Petroleum Exploration and Development, CNPC, Beijing 100083, China;
    4. Department of Earth Sciences, Zhejiang University, Hangzhou 310027, China
  • Received:2004-09-20 Online:2005-12-25 Published:2013-11-19

摘要:

柴达木盆地在第三纪时期位于北纬干燥气候带上,由于缺乏源远流长的河流,仅有短暂性洪水型河流补给水源,加上四周被高山环抱,所以形成了常年性内陆封闭咸水湖盆.咸水湖相中的烃源岩有机质丰度和成烃演化过程对生烃评价具有特殊意义.勘探证实柴达木盆地西部地区是以第三系盐湖相为烃源岩的油气富集区,烃源岩以含盐度高(15‰~60‰)、碳酸盐岩含量高(>20%)、有机碳含量低(一般低于0.5%)、烃转化率高(氯仿沥青"A"与有机碳含量之比一般为20%,最高可达60%;烃含量与有机碳含量之比一般为12%,最高可达40%)为其特征.同时,烃源岩的演化具有"两期成烃"的特点,即早期(Ro≤0.7%)形成未熟-低熟石油,晚期(Ro>0.7%)形成成熟-高成熟石油.

关键词: 柴达木盆地, 第三系盐湖相, 烃源岩, 地球化学特征, 成烃演化

Abstract:

The Qaidam Basin located in dry climatic zones of north latitude during the Tertiary Period.For the lack of continuous source of river and being surrounded by high mountains,it was only supplied by pluvial river temporarily and formed a perennial inland block saltwater basin.The issues of organic matter abundance for source rocks in salt lacustrine facies and evolutionary process of hydrocarbon generation play the significant roles in the assessment of hydrocarbon generation. Exploration indicated that the west region of Qaidam Basin is rich in oil and gas with source rocks of the Tertiary salt lacustrine facies. The source rocks are characterized by high salinity of 15 permillage to 60 permillage,high carbonate content over 20 percent,low average of total organic carbon content less than 0.5 percent,high percentage in conversion of hydrocarbon. The average ratio of chloroform bitumem "A" to the total organic carbon content(TOC) is 20 percent,and the highest ratio of "A" to TOC is 60 percent. The average ratio of hydrocarbon content(Hc) to TOC is 12 percent,and the highest Hc to TOC ratio is 40 percent. The evolution of source rocks has the characteristic of "two-stage hydrocarbon generation" of early stage and late stage. In the early stage when the vitrinite reflectance(Ro) was equal or less than 0.7 percent formed the immature to low-mature oil. In the late stage when Ro was larger than 0.7 percent formed the mature to high-mature oil.

Key words: Qaidam Basin, Tertiary salt lacustrine facies, source rock, geochemistry characteristic, hydrocarbon generation evolution

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