石油与天然气地质 ›› 2009, Vol. 30 ›› Issue (3): 337-342,349.doi: 10.11743/ogg20090313

• 海相碳酸盐岩 • 上一篇    下一篇

海相碳酸盐岩的形成环境与有机质特征

周新科, 许化政   

  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
  • 收稿日期:2009-01-05 出版日期:2009-06-25 发布日期:2012-01-16

Features of organic matter and formation environment of marine carbonate rocks

Zhou Xinke, Xu Huazhen   

  1. SINOPEC Petroleum Exploration and Production Research Institute, Beijing 100083, China
  • Received:2009-01-05 Online:2009-06-25 Published:2012-01-16

摘要:

海相碳酸盐岩形成于海水蒸发量大、生物繁盛、Eh和pH值容易改变的浅海陆棚相环境。海水的动荡性与高含氧量破坏了海洋中死亡生物的软体部分,造就了碳酸盐岩有机质的低丰度和低品位,TOC低于0.2%且干酪根为Ⅲ型或Ⅱ2型的碳酸盐岩在世界范围内具普遍性。因此,纯净碳酸盐岩不能成为有效烃源岩。碳酸盐岩随含泥量增加TOC变大,但仅有少量TOC大于0.5%的泥灰岩有可能成为有效烃源岩。

关键词: 浅海陆棚, 有机质丰度, 干酪根类型, 有效烃源岩, 沉积环境, 海相碳酸盐岩

Abstract:

Marine carbonate rocks are usually formed on neritic continental shelf where sea water evaporates fu-riously,living organism flourishes,and Eh and pH values change easily.Turbulent sea water with its high oxygen content destroys the soft parts of dead organism and forms carbonate rocks with low-abundance and low grade organic matters.Worldwide,carbonate rocks with TOC less than 0.2% and kerogen type of Ⅲ or Ⅱ2 are common.It is therefore concluded that pure carbonates can not serve as effective source rocks.The TOC of carbonate rocks increases as the shale content becomes bigger,and only a small amount of marls with TOC larger than 0.5% may be effective source rocks.

Key words: neritic continental shelf, abundance of organic matter, kerogen type, effective source rock, depositional setting, marine carbonate rock

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