摘要
为进一步研究不同孔隙下残余油饱和度的分布状况,以及残余油对于孔隙微观结构的影响,利用压汞法进汞毛管力曲线计算岩心原始孔隙半径;结合退汞毛管力曲线建立了不同孔隙半径所对应的残余油饱和度计算方法。在此基础上,利用分形理论研究空白岩心及退汞饱和度下的分形维数变化。结果表明：孔隙半径处于1.1～5μm范围相对大孔隙的分形维数高于半径处于0.03～1.1μm范围内小孔隙的分形维数,大孔隙不规则性强于小孔隙;同时在残余油饱和度下,岩心微观孔隙分形维数基本保持恒定,为2.065左右;且进汞时小孔隙维数D-in2、退汞时维数D分别与最大进汞饱和度和退汞饱和度具有明显线性关系。可见,通过开展对孔隙当中微观残余油分布的研究,对今后从降低残余油饱和度角度进行提高采收率研究具有非常重要的学术价值。
In order to study the distribution of different pore residual oil saturation and the residual oil effecting to pore microstructure further, using the curves of the mercury into the core, the core original pore throat radius can be calculated, and using the curves of the mercury out of the core, the mathmatic model of the residual oil saturation un- der different pore radius is established. On the basis of these, applying fraetal theory, the core fractal dimension un- der original condition and residual oil saturation condition can be studied. The results showed that the fractal dimen- sion of the pore throat radius in the range of 1.1 -5 p,m pore radius is higher than that of small pores in the range of 0. 03 ~ 1.1 pure. Irregularities of large pores are stronger than those of small pores ; while under the residual oil satura- tion, the core micro-pore fraetal dimension remains constant about 2. 065, the dimensions D_ira of the cores during mercury into the small pore have obvious linear relationship with the maximum intake of mercury saturation and the dimensions D during mercury out of the pore have the same relationship with the retreat mercury saturation. The study results of the residual oil distribution in microscopic pores can be used for enhanced oil recovery research and have a very important academic value to the perspective of reducing the residual oil saturation.
出处
《科学技术与工程》
北大核心
2014年第31期32-36,共5页
Science Technology and Engineering
基金
国家重大科技专项子课题(2009ZX05009006)资助
关键词
压汞毛管力
残余油
微观
分形维数
孔隙半径
mercury capillary force residual oil microcosmic fractal dimension pore radius
