微量元素组成在固体沥青-源岩对比中的应用

我国南方碳酸盐岩地区分布着许多被破坏了的古油藏,原来可溶沥青或原油经过成千上亿年的风化作用,已变成脉状或斑点状的不可溶固体沥青。由于固体沥青的不可溶性,许多常规有效的方法难以进行油源对比和进一步深入研究。作者发现原油与烃源岩之间的关系,类似于矿床形成过程中的矿藏与矿源(或矿液)之间的关系,矿源对比时常用微量元素来进行。那么原油或沥青从烃源岩中运移出来时,会不会将烃源岩有机质中的微量元素带来呢?为此,作者尝试测量固体沥青和可能烃源岩的微量元素并结合碳同位素等分析,找到了固体沥青真正的源岩,成功地进行了研究区的古油藏成因研究。 

APPLICATION OF MICROELEMENT COMPOSITION TO THE CORRELATION OF SOLID BITUMEN WITHSOURCE ROCKS

There distributes a lot of destroyed old oil pools in the carbonate rock areas of South China. Former dissolvable bitumen or crude oil has been changed into insoluble vein or mottled solid bitumen through hundreds of millions of weathering, Bacause of the insolubility of solid bitumen, it is difficult to make oil source correlation and further researches using many effective conventional methods. It is discovered that the relationship between crude oil and source rocks is similar to that between ore occurrence and provenance (or ore solution) in the course of deposit formation. The ore source correlation is usually conducted by microelements. That,will the microelements in organic source rocks be carried out when crude oil or bitumen migrates away from source rocks? For this reason,the authors attempted to measure the microelements in solid bitumen and potential source rocks. By combining carbon isotopic and other analysis, the true source rocks of solid bitumen are discovered. On this basis, the genesis of old oil pools in the study area is studied successfully.