四川盆地龙马溪组富有机质页岩形成主控因素

发布时间：2018-02-25 15:39

  本文关键词： 四川盆地 龙马溪组 富有机质页岩 地球化学指标　出处：《大庆石油地质与开发》2016年02期 　论文类型：期刊论文

【摘要】：四川盆地龙马溪组富有机质页岩是重要的烃源岩和页岩气储层。为了明确富有机质页岩形成控制因素,采用多种地球化学指标分析其沉积时的氧化还原条件、古生产力条件和陆源碎屑供给情况。结果表明:龙马溪组页岩具有高的有机碳含量,龙马溪组下部硅质页岩形成于贫氧环境,龙马溪组上部粉砂质页岩和黏土质页岩形成于氧化环境,由下至上还原环境逐渐遭受破坏;龙马溪组沉积时期古生产力为中—高等,下部硅质页岩段陆源供给较少,中部粉砂质页岩段陆源碎屑供给相对多,粗碎屑颗粒含量相对高,上部黏土质页岩以陆源黏土矿物为主;龙马溪组沉积物中埋藏有机碳含量与氧化还原环境指标、古生产力指标呈良好的相关性,与陆源碎屑供给参数相关性较差。龙马溪组富有机质页岩的形成主要受控于氧化还原条件和古生产力。
[Abstract]:The organic shale of Longmaxi formation in Sichuan Basin is an important source rock and shale gas reservoir. In order to determine the controlling factors of the formation of organic matter rich shale, various geochemical indexes are used to analyze the redox conditions during the deposition. The results show that the shale of Longmaxi formation has high organic carbon content, and the siliceous shale in the lower part of Longmaxi formation is formed in oxygen-poor environment. The silty shale and clay shale in the upper part of Longmaxi formation were formed in the oxidizing environment and gradually destroyed from the bottom to the upper reducing environment, the paleoproductivity of Longmaxi formation was medium to high during the sedimentary period, and the terrestrial supply of the lower siliceous shale formation was less. In the middle part of silty shale, there is a relatively large supply of terrigenous clastic materials, a relatively high content of coarse clastic grains, and the upper clay shale is dominated by terrestrial clay minerals, while the buried organic carbon content and the redox environmental indexes in the sediments of Longmaxi formation are the main ones. There is a good correlation between paleoproductivity index and terrestrial clastic supply parameters. The formation of organic matter rich shale in Longmaxi formation is mainly controlled by redox conditions and paleoproductivity.
【作者单位】： 中国石油大学地球科学学院;
【基金】：中国石化科技攻关项目“川东地区龙马溪组页岩气富集规律与分布预测”(G5800-14-ZS-KJB158)
【分类号】：P618.13
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本文编号：1534143