特低渗透砂岩储层微观孔隙结构特征

Research of Micro-Pore Structure in Super-Low Permeability Sandstone Reservoir

通过物性分析、扫描电镜、铸体薄片、高压压汞技术对鄂尔多斯盆地F油田延长组长81特低渗透砂岩储层样品进行分析测试,研究其微观孔隙结构特征。研究表明,研究区储层孔隙喉道类型多样是其渗透性差的主要原因,储层以残余粒间孔和溶蚀粒间孔为主。孔隙喉道偏细,多属小孔微喉道;喉道分布具有单峰、双峰和多峰的特点;储层非均质性增强,渗透率有增大的趋势;储层微裂缝较为发育。储层物性参数的差异、孔喉特征参数的差异等均归因于微观孔隙结构的差异。

By the physical property analysis,SEM,casting slice,and the technology of High pressure Hg injection,Super-low permeability sandstone samples of Chang 81 in F oil field in Ordos basin were tested,in order to analyze the micro-pore structure.The research shows the varieties of pores and throats are the main reasons that the permeability is low,and the primary pore and dissolved pore are main pores.The throat is inclined to be fine and belongs to small pore-microspic one.Distributions of throat are single apex,double apices and many apices.The higher the heterogeneity is,and the permeability is increasing.The microfracture is very good.The difference of quality,and of parameters of pore throat,and so on results from the difference of the micro-pore structure.