Organic compositions of lacustrine source rocks in Jiyang super-depression and its implication to petroleum geology
Organic compositions of lacustrine source rocks in Jiyang super-depression and its implication to petroleum geology
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DOI：
10.1007/s11434-006-0573-y
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发表时间：
2006
影响因子：
--
通讯作者：
Linye Zhang;Yitao Song;Guangli Wang;Difan Huang
中科院分区：
文献类型：
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作者：
Linye Zhang;Yitao Song;Guangli Wang;Difan Huang
采用CHCl3、MAC和CS2/NMP三种不同的提取方法，研究了中国东部最典型的陆相断陷盆地济阳超凹陷第三系四种未熟烃源岩的有机质组成。结果表明，不同沉积环境的烃源岩有机质化学成分存在较大差异。在盐湖下沉积的沙四段烃源岩中，约79%的有机质以非共价键形式存在，表明其有机质并非真正的干酪根，而主要由温度较低、易生烃的可溶性有机质组成。这就是东营凹陷沙四段生油岩发育未熟油的原因。相较之下，沙三段生油岩中约60%的有机质以共价键形式存在，表明沙三段生油岩主要由在较高温度下生成成熟烃的干酪根组成。对依次用三种溶剂提取的剩余固体烃源岩进行了热模拟实验。将模拟产物的氯仿萃取物与室温下得到的其他三种溶剂萃取物进行了比较。可见，显着的奇偶优势(OEP)主要是可溶有机质的特征，植烷主要以非共价键的形式存在于可溶有机质中，可溶有机质的特征与济阳凹陷低熟油相似。
The compositions of organic matter in four immature source rocks from Tertiary strata of Jiyang super-depression, the most typical continental rift subsidence basin in East China, have been studied by different extracting methods with CHCl3, MAC and CS2/NMP, respectively. The results suggest that there are great differences among the chemical compositions of organic matter in the source rocks derived from different depositional environments. About 79% of all the organic matter exists by non-covalent bond in the Es4source rocks which were deposited under the saline lacustrine, indicating that its organic matter is not the real kerogen, but mainly composed of soluble organic matter which is easy to generate hydrocarbon at lower temperature. This is why the immature oils were derived from Es4source rocks in Dongying depression. In contrast, around 60% of organic matter exists by covalent bond in Es3source rocks which were deposited under the deep brackish-fresh lacustrine, showing that Es3source rocks are mainly composed of kerogen producing mature hydrocarbon at higher temperature. The thermal simulation experiments, upon the remaining solid source rocks which were sequentially extracted by the three solvents, have been carried out. The chloroform extracts from the simulation product have been compared with the other three solvent extracts gained at room temperature. It is obvious that remarkable odd/even predominance (OEP) is mainly the characteristic of soluble organic matter; phytane mostly exists in the soluble organic matter by means of non-covalent bonds and characteristics of soluble organic matter are similar to these in immature oils produced in Jiyang super-depression.