抽油泵柱塞环槽结构对漏失量的影响研究

抽油泵工作过程中,由于泵筒与柱塞之间存在一定间隙,在柱塞两端的液体压差及剪切力的作用下,会使大量液体通过间隙漏失,对泵效产生严重影响。为分析抽油泵柱塞环槽结构对柱塞与泵筒间隙漏失量的影响机理,通过建立柱塞环槽不同结构的抽油泵模型,根据抽油泵工作特点,设定了不同边界条件下的多物理场耦合模型,通过数值模拟分析了槽宽、槽深、槽距、槽数和环槽位置对环槽内流体速度场及间隙漏失量的影响规律。分析结果表明:在环槽内形成的涡流受到槽宽与槽深这两个因素影响较大,当槽深和槽宽相接近时,所形成的涡流较为完整,且涡心几乎位于环槽中心,而环槽位置、槽距及槽数发生变化时,对环槽内所形成涡流的形状基本无影响;在一定范围内,随着槽深和槽宽的增大,漏失量逐渐减小,到达一定范围后,随着槽深和槽宽的进一步增大,漏失量不再随其发生明显变化。所得结论可为抽油泵漏失机理的进一步研究和结构改进提供指导。

Influence of the Plunger Ring Groove Structure on the Subsurface Pump Leakage

There is a certain clearance between the pump barrel and the plunger,so in the operating process of oil well pump,a large amount of liquid will be lost through the clearance under the action of the liquid pressure difference and the shearing force at both ends of the plunger,which has a serious impact on the pump efficiency.In order to analyze the influence mechanism of the ring groove structure in the pump plunger on the leakage through the clearance between the plunger and the pump barrel,this paper established the pump model for different ring groove structures.Then,multi-physical field coupling model under different boundary conditions was set according to the operating characteristics of oil well pump.Finally,the influence laws of groove width,groove depth,groove spacing,groove quantity and groove position on the fluid velocity field in the ring groove and the leakage through the clearance were analyzed by means of numerical simulation.The analysis results show that the vortex formed inside the ring groove is affected more by groove width and groove depth.When the groove depth is close to the groove width,the vortex center is nearly located in the center of the ring groove.The change of groove position,groove spacing and groove quantity has nearly no effect on the shape of the vortex formed in the ring groove.As groove depth and groove width increase within a certain range,the leakage decreases gradually.And beyond the range,the leakage doesn’t change greatly with the increase of groove depth and groove width.The research conclusions can provide the guidance for the further study of pump leakage mechanism and the structural improvement.