南方海相优质页岩的成烃生物研究

在以往海相优质烃源岩研究的基础上,利用扫描电镜结合能谱元素分析方法对优质页岩进行成分、成烃生物、形成环境和生烃潜力等综合研究,认为海相优质页岩成烃生物主要有3种类型:1)浮游藻类,包括硅质鱼鳞藻、疑源类(硅质光面球藻、原始硅藻及有机小刺藻等)、蓝藻类(钙质色球藻等)及钙质塔斯马尼亚藻等;2)底栖生物,包括硅质(或钡质或铁质等)藻席、硅质藻孢子囊、硅质藻丝体残片、硅质海绵及原始线叶植物(含粘土)等;3)菌类,包括钙质真菌菌丝(含有机质)、硅质细菌(含有机质)、硫细菌(可不含有机质)、铁细菌(含有机质)及纳米钙质细菌等。通过对不同层位成烃生物组合特征结合能谱元素数据,初步分析了优质页岩形成时的水体环境。现代藻类热压模拟实验和含单一成烃生物的实际油页岩样品热解实验研究表明,浮游藻类相当于Ⅰ型干酪根生烃潜力,底栖藻类相当于Ⅱ型干酪根生烃潜力。

HYDROCARBON-FORMING ORGANISMS IN EXCELLENT MARINE SOURCE ROCKS IN SOUTH CHINA

Based on previous studies,excellent marine source rocks in South China were collected and studied by Scanning Electron Microscope and Energy Dispersive Spectrometer.Compositions,hydrocarbon-forming organisms,sedimentary environments and hydrocarbon potential of the excellent marine source rocks were discussed.There are three types of hydrocarbon-forming organisms in the excellent marine source rocks: 1) Pelagic algae,including siliceous Mallomonas,Acritarchs(siliceous Leiosphaeridia,Diatom,Micrhystridium and so on),Cyanophyta(calcareous Chroococcus and so on),and calcareous Tasmanaceae.2) Benthic organisms,including siliceous or baritic or ferruginous algal mats,siliceous sporangium,siliceous filaments relic,siliceous sponge,and original Nematothallus(containing clay).3) Fungi,including calcareous fungi hypha(containing organic matter),calcareous bacteria(containing organic matter),sulfur bacteria(not always containing organic matter),iron bacteria(containing organic matter),calcareous nanobacteria,and so on.Palaeoenvironment was analyzed according the elements and hydrocarbon-forming organisms compositions.Modern algae hydrous pyrolysis in closed system and pyrogenation of oil shales which contain single hydrocarbon-forming organism were carried out.Hydrocarbon potential of pelagic algae was equivalent to type Ⅰ kerogen,and the benthic algae was equivalent to type Ⅱ kerogen.