东濮凹陷北部沙三段泥页岩岩相特征

The Lithofacies Characteristics of Es3 in the Northern Dongpu Depression

东濮凹陷北部沙三段泥页岩厚度大、分布广,具有良好的页岩气生烃潜力;但陆相湖盆泥页岩非均质性强,不同岩相生烃能力和储集性能差异较大。为厘清不同岩相的含油气性特征,通过偏光显微镜、X衍射等手段研究泥页岩微观岩相类型,发现东濮凹陷北部沙三段主要发育块状粉砂质泥岩相、纹层状膏质泥岩相、纹层状灰质泥岩相三种典型岩相及多种过渡岩相。通过对比不同泥页岩相地球化学特征、荧光特征、试油试气数据,发现深湖-半深湖环境中的纹层状灰质泥岩相是页岩油气赋存的优势岩相。

Unconventional oil and gas often appeared in the third section of Shahejie Formation （Es3） shale of the northern Dongpu Depression, suggested the huge shale oil and gas potential. Due to the complexity of the conti- nental lake basin facies, the heterogeneity of the shale is strong, the hydrocarbon generation ability and reservoir properties of different facies exists obvious difference. In order to clarify the control of different lithofacies, the core features of the shale, mineralogical features, fluorescence characteristics of Es3 shale to study the micro lithofacies types and characteristics was analyzed. The Es3 shale can be divided into three typical shale lithofacies： the mas- sive silty shale, the laminated calcareous shale and laminated gypsum shale, these lithofacies have good matching relationship with the sedimentary facies. By comparing the geochemical characteristics, the fluorescence character- istics and testing data of different lithofacies, it found that the the laminated calcareous shale lithofacies of the deep to semi-deep lacustrine environments is the favorable lithofacies of shale oil and gas occurrence.