地面驱动螺杆泵抽油杆柱弯曲的力学模型

用地面驱动螺杆泵采油时 ,井筒的弯曲或者抽油杆材质的不均匀性会导致抽油杆在井筒中的弯曲 ,从而改变抽油杆的受力状况。为了最大限度地减少因抽油杆受力的不确定性而对生产造成的危害 ,采用微元分析和分段迭代的方法 ,对抽油杆弯曲后的受力状况进行了研究。结果表明 ,除了正常作用在抽油杆上的扭矩和轴向力以外 ,抽油杆弯曲后还会受到由于弯曲变形引起的剪切应力、弯曲应力以及井筒与其接触的摩擦阻力和摩擦扭矩等。光杆扭矩和轴向力的计算方法应根据各种附加力的产生而发生改变。根据研究结果 ,建立了地面驱动螺杆泵抽油杆柱弯曲的力学模型 ,其计算结果与现场测试资料对比表明 ,该模型是比较准确的

Mechanic model for crooked rod of surface-driving progressive cavity pump

When surface driving progressive cavity pump is used for oil production, there are a lot of factors causing rod to be crooked such as winding well bore or material anisotropy of rod. Then the force acting on the rod may be changed. In order to avoid the loss caused by uncertainty of acting force on rod, the force states of crooked rod were analyzed with the differential method and iteration method. The results show that crooked rod stands the shearing force, bending stress, friction force and torque of friction for rod bending, except the torque and axial force on rod. The method for calculating torque and axial force may be changed with the extra forces on the crooked rod. A mechanic model for the crooked rod of the surface driving progressive cavity pump was established on the above results. The calculation result of this model was compared with the measured data. It is proved that the model is suitable and accurate on site.