定向井抽油杆柱横向振动仿真模型及扶正器布点优化  

Simulation model of lateral vibration of sucker rod string in directional wells and point arrangement optimization of centralizer

作　　者：董世民[1] 王宏博[1] Dong Shimin;Wang Hongbo(School of Mechanical Engineering,Yanshan University,Hebei Qinhuangdao 066004,China)

机构地区：[1]燕山大学机械工程学院,河北秦皇岛066004

出　　处：《石油学报》2020年第12期1686-1696,共11页Acta Petrolei Sinica

基　　金：国家自然科学基金项目(No.51974276);河北省自然科学基金项目(E2017203101)资助。

摘　　要：将定向井抽油杆柱在井筒内横向振动的力学模型简化为具有初弯曲的纵横弯曲梁在井筒约束条件下的横向振动模型。在模型中考虑了交变轴向载荷对抽油杆柱横向振动的激励,并提出了弯曲井筒是轴向运动抽油杆柱横向振动的一项主要激励。综合考虑弯曲井筒对轴向往复运动抽油杆柱横向振动的激励以及交变轴向载荷对抽油杆柱横向振动的激励,应用弹性碰撞理论描述井筒对抽油杆柱横向振动的约束,并基于弹性体振动理论建立了具有初弯曲的抽油杆柱在井筒约束条件下横向振动仿真的数学模型。基于定向井抽油杆柱横向振动仿真模型,建立了扶正器布点优化的数学模型。采用龙格库塔法实现了定向井抽油杆柱横向振动的仿真计算;通过循环迭代方法实现了扶正器的布点优化。研究结果表明:(1)仿真结果与油田实际情况相符,验证了模型的适用性;(2)杆管偏磨的危险点为井眼的造斜段与杆柱受压段。井眼造斜段杆管接触力较大,杆柱受压段杆管碰撞剧烈;(3)优化扶正器配置后,杆体、接箍不与油管接触,扶正器的最大杆管接触力均在许用接触应力以内,保证了抽油杆柱的工作寿命。In this study,the mechanical model of the lateral vibration of sucker rod string(SRS)in directional wells is simplified to a lateral vibration model of the longitudinal and horizontal bending beam with initial bending under constraint conditions of the wellbore.In addition to considering the excitation of the alternating axial load on the lateral vibration of SRS,the model proposes that the curved wellbore is a main excitation for the lateral vibration of SRS in axial motion.Comprehensively considering the excitation to the lateral vibration of SRS in axial reciprocating motion from the curved wellbore and the alternating axial load,respectively,this paper describes the constraints of wellbore to the lateral vibration of SRS when applying the elastic collision theory,and establishes a mathematical model of the lateral vibration simulation of the SRS with initial bending under constraint conditions of the wellbore.Based on the simulation model of lateral vibration of SRS in directional wells,a mathematical model is established for the point arrangement optimization of centralizer.Using the Runge-Kutta method,this study realizes the simulation calculation of the lateral vibration of SRS in directional wells;Using the loop iteration method,it realizes the point arrangement optimization of centralizer.The results show that:(1)the simulation results are consistent with the actual situation of the oilfield,thus verifying the applicability of the model;(2)the dangerous point of SRS and tubing wear is the build up section of borehole and the pressure section of SRS.The rod-tube contact force in the build up section of wellbore is relatively large,and the rod-tube collision in the pressure section of SRS is severe;(3)after optimizing the centralizer configuration,the rod body and coupling do not contact with the tubing,and the maximum rod-tube contact force of the centralizer is within the allowable contact stress,ensuring the working life of SRS.

关 键 词：抽油杆柱 横向振动 碰撞 仿真模型 杆管接触力 扶正器布点优化 

分 类 号：TE933[石油与天然气工程—石油机械设备]