深斜井条件下三维杆柱力学研究及应用

随着深层油藏的开发和绿色油田的推进,深井、大斜度井、丛式井日益增多,复杂井眼条件下有杆泵井举升存在偏磨严重,检泵周期缩短的问题,杆管偏磨机理一直没有得到较好解决。考虑井眼轨迹、流体黏滞阻力以及扶正器的影响,建立了三维杆柱动力学模型,通过求解得到了三维侧向力的动态分布规律。计算结果表明,抽油杆中和点以下侧向力方向易发生周期性变化,解释了杆柱偏磨的原因;侧向力方向周期变化会引起的杆管碰撞,也是加剧中合点以下杆管偏磨的重要原因。定量分析了多个参数对侧向力的影响,为防偏磨生产参数设计提供了理论依据。

3D rod mechanics research and application in deep deviated well conditions

With the development of deep reservoirs and promotion of green oilfields, there is an increasing number of deep wells, highly-deviated wells, cluster wells, etc. The rod pump wells under complex wellbore conditions have such problems as severe eccentric wear, short pump inspection period and that the rod eccentric wear mechanism has not satisfactorily addressed. Based on the effects of wellbore trajectory, fluid viscous resistance and centralizers, a 3D rod mechanic model was built, and the dynamic distribution regularity of 3D lateral force was solved. The calculations show that the direction of lateral force below the neutral point on the rod is prone to periodic change, which explains the rod eccentric wear. The periodic change in lateral force may cause rod collision, which is a key reason for severe rod eccentric wear below the neutral point. Quantitative analysis was conducted to the effect of a number of parameters on the lateral force, providing theoretical basis for the design of anti-eccentric production parameters.