三肇凹陷扶余油层中—低渗透储层微观孔隙结构特征及其分类

采用铸体薄片、共聚焦扫描电镜成像技术、常规压汞分析和恒速压汞分析等多种手段,对三肇凹陷扶余油层中—低渗透储层孔隙结构特征进行综合研究。结果表明,储层孔隙结构异常复杂,粒内溶孔、粒间溶孔等次生溶蚀孔隙构成了其主要储集空间,孔径大小在22.49~49.31 mm之间,孔喉连通性差异较大。在此基础上,以渗透率为主线,结合孔隙类型、孔喉半径、孔喉半径比以及孔喉连通性等参数,将研究区储层主要划分为中渗透储层和低渗透储层2种基本类型,前者以中渗透中孔细喉道型为主,后者又进一步细分为低渗透中孔细喉道型、低渗透小孔不均匀微细喉道型和低渗透小孔较均匀微细喉道型等3个亚类。明确储层微观孔隙结构特征及其分类,有利于进一步开展储层评价,对油田后期挖潜具有重要的指导意义。

Microcosmic Pore Structure in Low-Moderate Permeability Reservoir of Fuyu Oil Layer in Sanzhao Sag

By cast slices,co-focused SEM,traditional mercury-injection method,and constant rate mercury-injection method,the microcosmic pore structure in low-moderate permeability reservoir of Fuyu oil layer in Sanzhao sag was determined.The pore structure is very complex.The secondary dissolution pore(i.e.intragranular pore,intergranular pore) is the main type of reservoir,with average diameter of 22.49-49.31 mm and various connectivity between pore and throat.According to permeability,associating with pore type,por...