三维弯曲井眼抽油杆柱动力学模型建立与仿真

Establishment of dynamic model of suck rod string of 3D bending well bores and its simulation

针对处于复杂的交变应力状态下的抽油杆柱偏磨和断脱,在抽油杆动力学分析模型的基础上,建立了抽油杆三维力学综合分析模型,开发了相应的仿真分析软件系统,并利用该软件研究了三维井眼轨迹对抽油杆柱受力变形的影响.实例计算结果表明:井眼的曲率、挠率对抽油杆柱的悬点载荷、支反力、屈曲应力均有较大影响;根据抽油杆柱三维力学综合分析结果可以预测偏磨严重点位置,可减轻杆管之间偏磨,减少抽油杆柱井下断脱次数,延长修井周期,降低采油成本.

The directional well is a 3D curvature hole with buckling and contorting. The complexity of borehole makes the suck rod string, which moves up and down in the borehole, endure complex alternate stresses, which frequently result in the rod's uneven abrasion and break-off. On the basis of existing dynamic analysis model of the sucker-rod pumping system, a dynamic analysis model in 3D deviated wells has been established in this paper. Based on the theoretical research, an applied software is developed with Visual Basic 6.0 and Matlab 6.0. A systemic study has been carried out in the influence of three dimension curvature hole on the suck rod string's stresses and life-span. The simulation results are very useful to releasing abrasion between the rod strings and tubes, cutting down the break-off of rod strings, prolonging production maintenance period and reducing the production cost.