东营凹陷新近系馆陶组层序地层格架

Stratigraphic sequence framework of Neogene Guantao formation,Dongying sag

东营凹陷新近系馆陶组是河流相沉积环境下形成的,地层对比划分难度较大,影响了对新近系馆陶组的地质评价和勘探部署。以层序地层学的基本原理为指导,综合运用岩心、录井和测井资料,建立了东营凹陷新近系馆陶组短期基准面旋回岩—电关系识别模型,确定了馆陶组高分辨率层序地层格架由1个长期基准面旋回、5个中期基准面旋回和17个短期基准面旋回构成;通过岩性及其组合特征和测井曲线特征对比分析,利用井震结合技术,实现了全区的等时地层对比,明确了东营凹陷馆陶组厚度变化很大,总体上具有东厚西薄、北厚南薄和中央厚周缘薄的特点。

The Neogene Guantao formation of Dongying sag is formed in fluvial sedimentary environment,therefore,it is very difficult to implement the stratigraphic classification and correlation which are crucial for the geological evaluation and exploration deploy-ment.On basis of the principle of sequence stratigraphy,comprehensive core study,mud-logging observation and togging data,we established the identification model of relationship between lithology and electrical property in short-term base-level cycle of Guantao formation,and determined that the high-resolution sequence straligraphic framework of Guantao formation in Dongying sag is consisted of one long-term base-level cycles,five mid-term base-level cycles and seventeen short-term base-level cycles.By means of comparison and analysis of the characteristics of lithology and logging curve,and utilization of well to seismic integra-tion,we build the sequence stratigraphic framework,and realized the isochronous stratigraphic correlation of whole area,as well as the variation trend of the stratum thickness of Guantao formation in Dongying sag.It is believed that the thickness of Guantao formation varied greatly and has the trend of thickening eastward and thinning westward,thickening northward and thinning southward,and thickening in the center while thinning peripherally.