Study On The Micro Pore Structure And Heterogeneity Of Reservoir In Central Saertu Area

When the oilfild went into the high water period, because of Oil and water seepage, injection agent oil displacement, the formation and distribution of the remailing oil are occurred in the reservoir. That is bigger influenced by the reservoir of microscopic pore structure and microscopic heterogeneity. So, fund out microscopic pore structure and microscopic heterogeneity in the different sand body, there are a great significance to formulate increasing production measures and explorate remaining oil effectively.Based on the reservoir geology and optical mineralogy, we consider the analyzing core in the laboratory(the casting thin sections, ordinary thin mercury, injection, scanning electron microscopy, etc.) There is a in-depth research to the different development stages, the microscopic pore structure and heterogeneity of different sand done. That determines 5 characterization parameters of microscopic pore structure, they are the average pore radius, relative sorting coefficient characteristics, structural characteristic coefficient, the slope ratio of big-small pore throat and the smallest effective pore radius. There are also 4 parameters of micro heterogeneity, they are micro coefficient of variation, rush coefficient, uniformity coefficient and pore-throat ratio. According to the porosity and permeability of rock and characteristic parameters of typical pore structure, the micro pore structure, it is divided into five categories and seven small classes in Sazhong oilfield. From one to five class, It is gradually that permeability reduces, shaliness increases, the pore radius decreases, the connectivity is worse, heterogeneity is stronger.The paper nalyzes influence of the sedimentation, diagenes is and development process of microscopic pore structure and reservoir heterogeneity, when the rock was deposited, the hydrodynamic conditions was stronger, compaction was weak, the dissolution was stronger, the development time was longer, the micro pore throat was more development, and the heterogeneity was weak. It detemines the influence of microscopic pore structure and heterogeneity to the development effect, from class I to V of pore structure, small pore throat ratio is increasing, the effective seepage is reducing, the efficiency of displacement is discreasing gradually. When the pore structure types became bad, the distribution of pore throat became uneven, the connectivity of pore throat, the effective seepage channel was reducing, the microscopic remaining oil was increasing.