Characteristics of organic facies of Eogene hydrocarbon source rocks in Nanpu sag，Bohai Bay Basin

Key words:  organic facies  source rocks  Eogene  Nanpu sag  Bohai Bay Basin

Abstract:

Combined with organic petrology and sedimentology characteristics, the organic facies of the source rocks were comprehensively studied according to the geochemistry characteristics. The results show that the zones of the most important source rocks are distributed in the algal，floral-algal，algal-floral and floral facies. The development and distribution of source rocks are controlled by different types of organic facies. The excellent source rocks in the Nanpu sag were developed in the algal organic facies of deep iake-semideep lake and the floral-algal organic facies of semideep lake-shallow lake. The organic matters, which were deposited in a weakly oxidative and reducing environments, were developed in the organic facies of algal-floral organic inputs of the shallow lake and delta. This type of organic facies is chaotic facies of higher plant and aquatic organism, it is also good at generating the hydrocarbons. rIlie relatively poor source rocks were deposited in the floral organic facies, which parent material was higher plant of land sources.