Emulsion flow behavior in porous media is predominantly affected by the emulsion’s droplet size distribution, as the macro flow character is determined by the micro transport phenomena of emulsion droplets passing through pore constrictions. In this work, oil-in-water emulsions (O/W) with different droplet sizes but with the same oil concentration were first prepared and characterized by their interfacial tension, size distribution, stability, and bulk viscosity. Sandpack flow tests were then conducted to quantitatively investigate the plugging characteristics of the different emulsions in porous media. The results show that pressure drop of the emulsions in 1 μm² permeability sandpacks initially increases as emulsion droplet size increases from 1.57 to 3.58 μm, but then begins to decrease as the droplet size continues to increase. For a single emulsion droplet, a larger droplet size can result in a greater capillary resistance force, as it has a more significant “Jamin” effect in pore constrictions. However, for an emulsion system, the total pressure drop is also affected by droplet number. A larger droplet size means a smaller droplet number in the emulsion system. The macro flow character of emulsions in porous media is determined both by droplet size and droplet number. A new mathematical model, which incorporates geometry of the porous media, emulsion droplet size, emulsion droplet number, and interactions between droplets and porous media was developed to theoretically describe the plugging of an emulsion in the sandpacks. For the first time, this model takes into account the size difference between the pore body and the pore throat of a real porous medium when simulating emulsion transport. Results calculated from the newly proposed model appear to match well with the experimental data, with the smallest average error being 7.67%.

中文翻译：

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水包油型乳液在多孔介质中的堵塞能力：实验与模型研究

多孔介质中的乳液流动行为主要受乳液液滴尺寸分布的影响，因为宏观流动特性取决于乳液液滴通过孔道收缩处的微传输现象。在这项工作中，首先制备具有不同液滴尺寸但具有相同油浓度的水包油乳液（O / W），并通过其界面张力，尺寸分布，稳定性和堆积粘度对其进行表征。然后进行沙包流量测试以定量研究多孔介质中不同乳液的堵塞特性。结果表明乳液的在1微米该压降²渗透性沙堆最初随着乳液液滴尺寸从1.57μm增加到3.58μm而增加，但随后随着液滴尺寸持续增加而开始减小。对于单个乳液液滴，较大的液滴尺寸会导致较大的毛细阻力，因为它在孔道收缩中具有更显着的“ Jamin”效应。但是，对于乳液体系，总压降也受液滴数的影响。较大的液滴尺寸意味着乳液体系中的液滴数量较小。乳液在多孔介质中的宏观流动特性取决于液滴大小和液滴数。一个新的数学模型，其中包含多孔介质的几何形状，乳剂液滴尺寸，乳剂液滴数量，研究了液滴与多孔介质之间的相互作用，以从理论上描述乳液在沙袋中的堵塞。该模型首次在模拟乳液传输时考虑了真实多孔介质的孔体和孔喉之间的尺寸差异。从新提出的模型计算出的结果似乎与实验数据非常吻合，最小的平均误差为7.67％。