Abstract: There exist some friction contacts between reciprocating rod string and tube in the direction of well depth and circumference of well bore.A nonlinear dynamics model for describing the friction contact was built on the basis of the vibration theory.The contact elements to describe the random impact contact state were constructed.The analysis and calculating methods for the parameters of rod string were proposed by combining the nonlinear theory and finite element method with space beam element.This method was applied to the Well 10-6551 in Daqing Oilfield.The contact load can be determined by the calculation method,and the positions of centralizer were forecasted according to the distribution of contact load.The average contact load can be reduced by 50.6 N and the side-wear can be lowered by using this method.

Key words: pumping rod tube dynamics analysis friction contact load nonlinear dynamics model finite element method

摘要： 针对细长抽油杆上下往复运动时沿井深与井眼圆周方向产生摩擦接触的问题,根据振动理论,建立了抽油杆柱非线性动力学模型。根据非线性理论和有限元理论,采用接触单元,描述了抽油杆与油管的接触状态,并与空间梁单元结合,在考虑实际边界条件下提出了抽油杆柱参数的计算方法。对大庆油田10-6551井进行了模拟,通过计算,定量地描述了抽油杆与油管接触力的变化。根据接触力的分布状态,计算了扶正器的安装位置。用这种方法使接触力平均降低50.6N,减缓了抽油杆柱的偏磨。该方法已在大庆部分采油厂得到推广和应用。

关键词: 抽油杆, 油管, 动力学分析, 摩擦接触力, 非线性动力学模型, 有限元法