石油与天然气地质 ›› 2008, Vol. 29 ›› Issue (3): 348-354,347.doi: 10.11743/ogg20080310

• 油气地质 • 上一篇    下一篇

西藏羌塘盆地中生界海相烃源岩特征

伍新和1, 张丽2, 王成善3, 伊海生4   

  1. 1. 中国石油化工股份有限公司, 石油勘探开发研究院, 北京, 100083;
    2. 中国石油天然气股份有限公司, 新疆油田分公司, 石油勘探开发研究院, 新疆, 克拉玛依, 834000;
    3. 中国地质大学, 北京, 100083;
    4. 成都理工大学"油气藏地质及开发工程"国家重点实验室, 四川, 成都, 610059
  • 收稿日期:2008-01-29 出版日期:2008-06-24 发布日期:2012-01-16

Characteristics of the Mesozoic marine source rocks in the Qiangtang Basin,Tibet

Wu Xinhe1, Zhang Li2, Wang Chengshan3, Yi Haisheng4   

  1. 1. Research Institute of Petroleum Exploration & Production, SINOPEC, Beijing 100083, China;
    2. Research Institute of Exploration & Development, Xinjiang Oilfield Company, Petro China, Karamay, Xinjiang 834000, China;
    3. China University of Geosciences, Beijing 100083, China;
    4. State Key Laboratory of Oil/Gas Reservoir and Exploitation Geology, Chengdu University of Technology, Chengdu, Sichuan 610059, China
  • Received:2008-01-29 Online:2008-06-24 Published:2012-01-16

摘要:

羌塘盆地海相地层发育,沉积厚度大(最厚处可达万米),其中以侏罗系厚度最大。羌塘盆地中生代具有广泛分布且发育良好的三叠系肖茶卡组、侏罗系布曲组、夏里组和索瓦组4套烃源岩。烃源岩主要为灰岩和泥岩,最厚处超过3000m。上三叠统的肖茶卡组、中侏罗统布曲组烃源岩厚度大、有机质类型主要为Ⅱ型、有机碳含量平均1.5%以上、成熟度从成熟到过成熟均有分布,而且埋藏较好,生烃量大,是盆地油气的主要来源;索瓦组烃源岩虽然厚度大、有机质类型主要为Ⅰ型和Ⅱ型,但出露较多。烃源岩有侏罗纪晚期至白垩纪早期和新近纪早期两次生烃高峰。

关键词: 烃源岩, 有机质类型, 油气分布, 海相, 中生界, 羌塘盆地

Abstract:

Qiangtang Basin has well-developed thick marine deposits with the Jurassic as the thickest(ten thousand meters).Four sets of high quality source rocks,namely the Triassic Xiaochaka Formation,the Jurassic Buqu,Xiali,and Suowa formations,are extensively distributed in the Mesozoic Qiangtang basin.These source rocks are mainly composed of limestone and mudstone with a maximum thickness over 3000 m.The source rocks in the Upper Triassic Xiaochaka Formation and the Middle Jurassic Buqu Formation have larger thickness and their organic matters are mainly of type Ⅱ with maturity varying from mature to over-mature,and average TOC is over 1.5%.They have favorable burial conditions and are the main hydrocarbon source in the basin.The Jurassic Suowa Formation is also rather thick and its organic matters are of mostly type Ⅰ and Ⅱ,however,the formation was over exposed and not favorable for hydrocarbon generation.There were two peaks of hydrocarbon generation:late Jurassic-early Cretaceous and Neogene.

Key words: source rock, type of organic matter, oil and gas distribution, marine, Mesozoic, Qiangtang Basin

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