有机相研究及其在盆地分析中的应用

Organic Facies Studies and Their Use in Sedimentary Basin Analysis

有机相是具有一定丰度和特定成因类型的有机质的地层单元，决定有机相类型的最重要参数是干酪根的成因类型。为了反映沉积盆地中有机相的时空分布，我们提出了有机相组合和盆地有机充填序列等新概念。有机相及有机相层序、有机充填序列和有机相组合不仅是预测和在三维空间确定生油岩的分布、预测主力生油岩的排烃期和排出产物的组成的有效工具，而且可以弥补以骨架砂岩体为主要研究对象的沉积学分析的不足，在确定层序界线或不整合面的位且、研究盆地的构造沉降和沉积充填史等方面发挥重要作用。

An organic factes is defined as a mappable stratigraphic unit containing organic matter (OM)of a particular genetic type in cartaain abundance. A new organic factes classification, which is based on indicative genetic kerogen (OM) type, is proposed. The improved definition and classification makes organic factes capable of reflecting the origin. diagenetic alternation of organic matter comprehensively, and, the organic facies thus defined and classified, which must be identified on the basis of synthetical parameters other than by atomic H/C ratios and/or Rock-Eval Hydrogen index values merely. Several new concepts concerning organic factes such as Vertical Organic Facies Sequence (VOFS), Organic Facies Association(OFA) and Organic Basin - fill Sequence (OBFS) are advanced, and their significance in basin analysis is discussed in detail.Several cases are presented in this peper which confirm that organic facies, especially VOFS, OFA and OBFS analysis Can not only become a very use full tool for prediction and three-dimensional mapping of petroleum source rocks. but also make up for some Shortcomings of sedimentological studies that put the stress on coarse rocks, and therefore may play a distinctive role in identifying and accurately locating unconformities or sequence/ systems tract boundaries as well as in reconstructing the tectonic subsidence and sedimentary fill histories of sedimentary basins.