有机地球化学参数在层序划分对比中的应用——以冀中拗陷束鹿凹陷沙三下亚段为例

深水细粒沉积层系的层序地层单元细分和对比，是建立合理的层序地层格架的关键，也是进行深水区岩性油气藏勘探开发的一项重要基础研究工作。但往往由于细粒沉积层系层序地层单元划分标志不明显，其划分对比较为困难，这也是层序地层学研究的难点。依据高分辨率层序地层学原理，从沉积层序的成因及其表现入手，应用表征沉积环境或沉积物特征的有机地球化学参数在纵向上的周期性变化规律，对渤海湾盆地冀中坳陷束鹿凹陷沙三段下亚段半深湖—深湖相泥灰岩沉积进行了层序地层单元划分和对比，较好地识别出了4级旋回与5级旋回，为建立高分辨率层序地层格架奠定了基础。

Application of Organic Geochemical Parameters in Sequence Classification and Correlation: a case study from Lower Es3 in Shulu Sag Jizhong Depression

It is the key factor for establishment of scientific sequence stratigraphy framework to conduct sequence stratigraphic unit classification and correlation of deep-water fine sedimentary series.In addition,it is one important basic research for exploration and development of lithologic oil and gas reservoirs in deep-water areas.Its classification marker,which is usually indistinct,handicaps sequence stratigraphic unit correlation of deep-water fine sedimentary series and acts as one difficult point for sequence stratigraphy research.On the basis of high resolution sequence stratigraphy theory,this paper starts with origin and presence of sedimentary sequence and carries out sequence stratigraphic unit classification and correlation for semi-deep lake to deep lake marl deposit in lower Es3 of Jizhong depression in Shulu sag,Bohai Bay Basin by using periodical variation rules in vertical of organic geochemical parameters that present sedimentary environment or sediment characteristics.And consequently,cycle grade-4 and grade-5 are distinguished in a better way,which provides basis to establish high-resolution sequence stratigraphy framework.