Polymer flooding is crucial in hydrocarbon production, increasing oil recovery by improving the water-oil mobility ratio. However, the high viscosity of displacing fluid may cause problems with sand production on poorly consolidated reservoirs. This work investigates the effect of polymer injection on the sand production phenomenon using the experimental study and numerical model at a laboratory scale. The experiment uses an artificially made sandstone based on the characteristics of the oil field in Kazakhstan. Polymer solution based on Xanthan gum is injected into the core to study the impact of polymer flooding on sand production. The rheology of the polymer solution is also examined using a rotational rheometer, and the power-law model fits outcomes. We observe no sand production during the brine injection at various flow rate ranges. However, the sanding is noticed when the polymer solution is injected. More than 50% of cumulatively produced sand is obtained after one pore volume of polymer sand is injected. In the numerical part of the study, we present a coupling model of DEM with CFD to describe the polymer flow in a granular porous medium. In the solid phase, the modified cohesive contact model characterizes the bonding mechanism between sand particles. The fluid phase is modeled as a non-Newtonian fluid using a power-law model. We verify the numerical model with the laboratory experiment result. The numerical model observes non-uniform bond breakage when only a confining stress is applied. Alternatively, the injection of the polymer into the sample leads to a relatively gradual decrease in bonds. The significant difference in the pressure of the fluid results in its higher velocity, which causes intensive sand production at the beginning of the simulation. The ratio of medium-sized produced particles is greater than the initial ratio of those before injection.

翻译：聚合物驱通过改善水油流度比提高原油采收率，在油气生产中具有关键作用。然而，驱替液的高粘度可能导致弱固结储层出现出砂问题。本研究通过实验室尺度的实验研究和数值模型，探究聚合物注入对出砂现象的影响。实验采用基于哈萨克斯坦油田特性的人工合成砂岩，注入基于黄原胶的聚合物溶液以研究聚合物驱对出砂的影响。使用旋转流变仪分析聚合物溶液的流变特性，其测试结果符合幂律模型。在多种流速范围的盐水注入阶段均未观察到出砂现象，但注入聚合物溶液后开始出现出砂，注入一个孔隙体积的聚合物砂后累计产砂量超过总量的50%。在数值研究部分，我们提出DEM与CFD的耦合模型来描述颗粒多孔介质中的聚合物流动。固相采用修正粘聚接触模型表征砂颗粒间的粘结机制，液相则通过幂律模型作为非牛顿流体建模。数值模型经实验室实验结果验证，在仅施加围压条件下可观察到非均匀键断裂现象。而将聚合物注入样品后，键断裂呈相对渐进式减少特征。流体压力差异导致其流速升高，造成模拟初期出现强烈出砂现象，且产出颗粒中中等粒径占比高于注入前的初始比例。