We examine the role of preshearing on the flow properties of polymer solutions containing essentially an acrylamide-based copolymer obtained from an emulsified polymer emulsion inverted by a surfactant. The polymer solutions were presheared using three methods: (1) a Buddeberg disperser, (2) an Ultra-Turrax disperser, and (3) pressure-driven flow through a capillary. Shearing the polymer solution was done under fast flow to induce high stretching of the polymer chains and thus promote the break-up of the longest ones (i.e., decrease in relaxation time and shear-thinning level). The unsheared and presheared polymer solutions were forced through sand packs to compare their corresponding flow resistances. We observed that the reduction in the viscosity and screen factor of the presheared polymer solutions is path independent regardless of the shearing device. We found a critical Weissenberg number (Wi_c ∼ 13) above which the viscosity of the polymer solutions started to decrease. The resistance factor for the polymer solutions presheared with the Ultra-Turrax disperser at an energy input of 31.3 and 290.7 MJ/m³ was nearly 3 and 7 times, respectively, lower than for the unsheared polymer solution, while the viscosity decreased only by 27 and 48%, respectively. The sand-pack experiments were successfully interpreted using a numerical model taking into account time-dependent retention. The model showed that the flow of the presheared polymer solutions through the sand packs was enhanced mainly due to the breaking of the longest polymer chains, which results in smaller mechanical entrapment. This preshearing of the water-soluble polymers can be used in multiple industrial applications, including chemical enhanced oil recovery and optimization of polymer processing.

中文翻译：

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通过预剪切增强水溶性聚合物通过多孔介质的流动性

我们研究了预剪切对聚合物溶液流动特性的作用，该聚合物溶液主要包含由表面活性剂转化后的乳化聚合物乳液制得的丙烯酰胺基共聚物。使用三种方法对聚合物溶液进行预剪切：（1）Buddeberg分散器，（2）Ultra-Turrax分散器，和（3）通过毛细管的压力驱动流。在快速流动下完成聚合物溶液的剪切，以引起聚合物链的高拉伸，从而促进最长链的断裂（即，弛豫时间和剪切稀化水平的降低）。将未剪切和预剪切的聚合物溶液强制通过沙包，以比较它们相应的流阻。我们观察到，与剪切装置无关，预剪切的聚合物溶液的粘度和筛分系数的降低与路径无关。我们找到了一个关键的魏森伯格数（Wi _c〜13），高于此，聚合物溶液的粘度开始降低。用Ultra-Turrax分散机预剪切的聚合物溶液的电阻系数在能量输入为31.3和290.7 MJ / m ^{3的情况下}粘度分别比未剪切的聚合物溶液低近3倍和7倍，而粘度仅分别降低27％和48％。考虑到时间依赖性的保留，使用数值模型成功地解释了沙堆实验。该模型表明，预剪切聚合物溶液流过沙堆的流量增加，这主要是由于最长的聚合物链断裂所致，从而导致较小的机械截留。水溶性聚合物的这种预剪切可用于多种工业应用，包括化学增强的采油率和优化的聚合物加工。