东营凹陷中央构造带西段沙三中沉积微相研究

SEDIMENTARY MICROFACIES IN THE MIDDLE SECTION OF THE THIRD MEMBER OF SHAHEJIE FORMATION AT THE WESTERN PART OF CENTRAL STRUCTURAL ZONE IN DONGYING SAG

从区域地质背景出发 ,对岩心观察、粒度分析、镜下鉴定结果及测井曲线形态等进行的综合分析表明 ,东营凹陷中央构造带西段Es中3沉积早中期主要属于半深湖—深湖背景下的浊积扇相沉积 ,Es中3沉积中后期属浊积扇相和三角洲相沉积。其中 ,浊积扇可分为有水道的远源浊积扇、与三角洲有关的近源滑塌浊积扇 ;三角洲相在该区主要发育三角洲前缘亚相。指出了Es中3不同沉积期各相带的空间组合及分布特征。结合测试资料分析 ,辫状水道微相和滑塌浊积扇的中扇为有利相带 ,从而为本区Es中3油气勘探和开发提供了依据。

On the basis of regional geologic background, the analyses on core, grain size, thin section, shape of the log curves show that the western part of the central structural zone of Dongying sag mainly belongs to turbidity facies in the early and middle period of the middle section in the third member of Shahejie Formation. In the middle and late period, it belongs to turbidity facies and delta facies. According to the cause of formation, the turbidity facies can be classified to far range turbidity facies, short range collapse turbidity facies, second forming turbidity facies. At the delta facies, there mainly are delta front subfacies. The facies association and distribution are presented. The channel microfacies and the middle fan of the collapse turbidity facies are the best fasies.