For oil wells with high sand content, traditional oil well pumps easily get stuck. Increasing the gap between the plunger and the pump cylinder can effectively prevent the sticking, but the gap leakage also increases, resulting in a decrease in the volumetric efficiency of the pump. As shown in this paper, when a rectangular groove is formed in the plunger of the oil well pump, it can significantly reduce the leak rate. In order to reveal the flow resistance mechanism of the gap seal structure with rectangular groove and the reasonable design of the seal structure parameters, the flow characteristics in the gap seal structure with rectangular groove are studied by CFD technology. The results show that the gap seal structure with rectangular groove reduces the leakage amount by 87% compared with the prototype gap seal structure. The optimal number of rectangular grooves is 3-4. The sealing effect of the rectangular groove at the inlet of the pump is better than that at the pump outlet. The rectangular groove spacing has little effect on the leak rate.

中文翻译：

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矩形槽油井泵间隙密封结构的漏流机理

对于含砂量高的油井，传统油井泵容易卡死。增大柱塞与泵缸之间的间隙可以有效防止卡死，但间隙泄漏量也增大，导致泵容积效率下降。如本文所示，当油井泵柱塞上形成矩形凹槽时，可显着降低泄漏率。为了揭示矩形槽间隙密封结构的流动阻力机理和密封结构参数的合理设计，利用CFD技术研究了矩形槽间隙密封结构的流动特性。结果表明，矩形槽的间隙密封结构与原型间隙密封结构相比，泄漏量减少了87%。矩形凹槽的最佳数量为 3-4。泵入口处矩形槽的密封效果比泵出口处的密封效果好。矩形槽间距对泄漏率影响不大。