Effect of Wetting-Phase Viscosity on Cocurrent Spontaneous Imbibition

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• 作者：Qingbang Meng ; Huiqing Liu ; Jing Wang ; Hongling Zhang
• 刊名：Energy & Fuels
• 出版年：2016
• 出版时间：February 18, 2016
• 年：2016
• 卷：30
• 期：2
• 页码：835-843
• 全文大小：548K
• ISSN：1520-5029

文摘

Spontaneous imbibition is an important mechanism for oil recovery in naturally fractured reservoirs. Understanding the effects of fluid viscosity on spontaneous imbibition is important for the design of injection projects and the prediction of reservoir production performances. We previously focused on the effects of the nonwetting-phase viscosity on spontaneous imbibition (Meng Energy Fuels 2015, 29, 686−694), and we now investigate the effects of the wetting-phase viscosity on spontaneous imbibition. Different wetting-phase viscosities were obtained by mixing glycerol with synthetic seawater, and the wetting-phase viscosities varied from 1 to 61.5 mPa s. Experiments on cocurrent imbibition were conducted with both glass-bead and quartz-sand packings with different wetting-phase viscosities. The geometry of the glass bead was spherical and regular with a narrow size distribution, and the geometry of the quartz sand was angular and irregular with a wide size distribution. The residual oil saturation in glass-bead packing was much lower than that in quartz-sand packing because of the different pore geometries and different pore size distributions of the packings. Unlike in conventional water flooding experiments, the residual oil saturation was found to be independent of the wetting-phase viscosity for both glass-bead and quartz-sand packings. Capillary number calculations showed the remarkable result that the capillary number also seemed to be independent of the wetting-phase viscosity, which might result in similar residual oil saturations for different wetting-phase viscosities. In addition, a modified scaling group aimed at cocurrent imbibition was developed, and the correlation of the imbibition data was improved by use of the modified scaling group.