辫状河三角洲岩相特征及沉积模式——以鄂尔多斯盆地苏南地区盒8段为例

Lithofacies characteristics and sedimentary model of braided delta:a case study of He 8 member in the southern Sulige,Ordos Basin

鄂尔多斯盆地苏南地区盒8段是苏里格气田重要的储集层,为搞清研究区目的层的岩相特征及沉积模式,对22口井的岩心进行了观察描述,共识别出8种岩相和4种岩相组合类型,并根据测井曲线的形态特征、接触关系等,对167口井的测井曲线进行了分类,建立了测井相模板;结合岩相和测井曲线特征,又划分出8种沉积微相。最后总结出4种岩相组合在沉积模式中的分布特征为:组合类型A分布于北部辫状河三角洲平原,组合类型B分布于北部辫状河三角洲平原和前缘的过渡带,组合类型C分布于南部辫状河三角洲前缘的河道发育区,组合类型D分布于西南部辫状河三角洲前缘的深湖区。

The He 8 member（the eighth member of Shihezi Formation） in southern Sulige is important reservoir of Sulige Oilfiled, Ordos Basin. In order to make clear the lithofacies characteristics and sedimentary models of the target strata in the study area, there is an important guiding effect for the oil and gas exploration. The typical lithofacies of Shihezi Formation was divided into eight types through core observation of 22 wells, and the litho- facies assemblies were divided into four types. According to the shape characteristics and contact types of log- ging curves of 167 wells, the logging curves were divided into four types. Combined with lithofacies and logging curves, the sedimentary microfacies were divided into eight types. The distribution of the lithofacies assemblages and sedimentary model were summarized. The assembly A developed in braided delta plain in the north, the as- sembly B developed in the transition area between the braided delta plain and braided delta front in the north, the assembly C developed in channel of braided delta front in the south, and the assembly D developed in deep lake of braided delta front in the southwest.