志丹油田正22井区长8储层特征分析

Analysis on Chang8 Reservoir Characteristics in Zheng22 Wellblock of Zhidan Oil Field

通过该区域沉积相的分析来确定研究地区主要发育水下分流河道、河口砂坝、水下天然堤及分流间湾四种沉积微相类型。并通过岩石薄片的鉴定和统计,结合扫描电子显微镜下观察对储层岩石进行了特征分析,分析结果表明,研究区长8储层物性较差,胶结物成分多样,总体来说研究区域长8油藏属于典型的特低渗透岩性油藏。其中长821小层的孔隙度、渗透率相对较高,含油饱和度也最高。

Through the analysis of sedimentary facies, the study area was identified as four sedimentary microfiches types, including developed underwater distributaries channel, mouth bar, subsea natural barrier and interdistributary bay. And through the rock thin section identification and statistics, by scanning electron microscope, the characteristics of reservoir rock were analyzed. The analysis results showed that Chang8 reservoir in the study area had poor physical properties, cement composition was varied. Overall Chang 8 reservoir belonged to the typical low permeable lithologic reservoir. The porosity and permeability of Chang 8_2~1 layer were relatively high, the oil saturation was the highest, too.