稠油井抽油杆柱粘滞摩擦载荷计算分析

随着有杆抽油机在稠油井的应用越来越广泛，抽油杆的粘滞摩擦载荷问题日益显著。目前通常采用等效阻尼系数来计算杆柱的粘滞摩擦载荷，但无法准确反映粘滞摩擦载荷的变化情况，造成抽油机设计不够合理，效率不高等问题。文章以油管内稠油作为研究对象，建立了管内液体的动力学方程，求解出管内液体的速度分布。并以此为基础，结合牛顿内摩擦定律，形成了稠油井抽油杆柱粘滞摩擦载荷的计算方法。以胜利油田某稠油井为例，开展了抽油杆柱粘滞摩擦载荷计算分析，求解出了该井在一个运动周期内抽油杆粘滞摩擦载荷的变化情况。通过敏感性分析得出：在上冲程，增大抽油杆直径和油管直径或减少柱塞直径均会使杆柱的粘滞摩擦载荷变大；在下冲程，增大油管直径或减少抽油杆直径均会使杆柱的粘滞摩擦载荷变小，但柱塞直径的变化对杆柱的粘滞摩擦载荷没影响。研究结果对稠油井抽油机的设计以及抽油杆的选择提供了一定的理论依据。

Calculation and Analysis of Viscous Friction Load of Sucker Rod Column in Heavy Oil Well

With the increasing use of rod pumping units in heavy oil wells, the problem of viscous friction loads on sucker rods has become increasingly significant. At present, the equivalent damping coefficient is usually used to calculate the viscous friction load, but it cannot accurately reflect the change of the viscous load, which causes the design of the pumping unit to be unreasonable and the efficiency is not high. In this paper, aiming at the heavy oil in the tube, the dynamic equation of the liquid in the tube is established, and the velocity distribution of the liquid in the tube is solved. Based on this, combined with Newton''s internal friction law, the calculation method of the viscous friction load of the sucker rod column in heavy oil well is formed. Taking a heavy oil well in Shengli Oilfield as an example, the calculation and analysis of the viscous friction load of the sucker rod column is carried out, and the change of the viscous friction load of the sucker rod in one motion cycle is obtained. Through the sensitivity analysis, it is concluded that increasing the sucker rod diameter and the tubing diameter or reducing the plunger diameter will increase the viscous friction load of the pole on the upstroke; increase the tubing diameter or reduce the sucker rod diameter will make the viscous friction load of the column smaller on the downstroke, but the change of the plunger diameter has no effect on the viscous friction load of the column. The research results provide a theoretical basis for the design of heavy oil well pumping unit and the selection of sucker rod.