水驱、化学驱后微观剩余油赋存状态和分布规律是继续挖潜的基础。目前分析微观剩余油普遍采用密闭取心磨制薄片的方法，这样就破坏了多孔介质中流体的原始状态。为此，本文选用大庆油田葡12组1000 mD左右的天然岩心，进行室内驱替实验。采用纳米CT技术，在不破坏岩心内部结构且保持孔隙中流体原始赋存状态的前提下，扫描驱替后岩心孔隙中不同流体的分布状态，通过计算机三维重建技术还原出孔隙中水和不同类型剩余油的三维形貌，再现了乳状、簇状、粒间吸附状、孔隙表面薄膜状、颗粒吸附状剩余油的三维形态。并初步认识了不同化学驱替手段对各类微观剩余油的动用程度。%It is the basis of producing remaining oil and improving reservoir development to study the existent state and distribution rule of micro⁃remaining oil after water flooding or chemical flooding. At present, the general analysis method of micro⁃remaining oil is grinding flaky rock sample after sealed coring. However, the liquid original existent state stored in porous medium is damaged by using this method. In this paper, 1 000 mD natural cores of certain block in Daqing oilfield were chosen to conduct displacement experimental programs. Three⁃dimensional distribution states of remaining oil were reappearance by Nano⁃CT: emulsus, intergranular absorption⁃like, particles adsorption⁃like, cluster⁃like, especially the remaining oil of cluster⁃like produced by W/O emulsion which was never discovered by 2D observation techniques before. By further quantitative analysis, the main remaining oil distribution state in samples were film⁃like of pore surface, intergranular absorption⁃like and particles adsorption⁃like.
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