塔中地区奥陶系鹰山组精细划分

Fine Division of Yingshan Formation of Ordovician in Tazhong Area,Tarim Basin

塔里木盆地塔中地区奥陶系鹰山组碳酸盐岩是盆地油气勘探开发的重点层位,但由于鹰山组顶部存在一个区域性的不整合面导致不同区块出露地层层位差异较大,给认识储集层的分布造成了一定的困难。根据生物化石、岩性组合特征、测井及地震资料,对鹰山组小层的发育特征进行了详细研究并建立了鹰山组小层划分对比格架。将鹰山组自上而下划分为鹰一段—鹰四段,进而将鹰一段细分为2个亚段、鹰二段细分为3个亚段,地层出露和分布具有区域分带性和良好的可对比性,储集层的发育层位和小层分布具有良好的相关性,这一研究成果为研究盆地碳酸盐岩储集层的成因和分布奠定了可靠的地层学基础。

The Ordovician carbonate rocks in Yingshan formation has become an important position for oil and gas exploration and development in Tazhong area of Tarim basin,but at the top of Yingshan formation there exist a regional uncomformity which leads to big differences among outcrop horizons in different blocks.This paper presents the classification and correlation framework of Yingshan formation,based on bio-fossils,lithology combination,log response,seismic data.It can be divided into Ying-1 member-Ying-4 member,and the Ying-1 member can be sub-divided into two sub-members,the Ying-2 member can be divided into three sub-members.The outcrops and their distributions have regional zonation and good correlatability,and the development horizons of the reservoir and the distribution of sub-layers have good correlation,which provides a reliable stratigraphy basis for study of origins of the carbonate reservoirs and their distributions in this basin.