地面驱动螺杆泵采油系统抽油杆柱运动模型

根据垂直井地面驱动螺杆泵采油系统的工作特点，利用抽油杆柱的动力学分析结果，建立了抽油杆柱运动模型，并给出了其有限差分解。利用该模型，可以根据在地面测试的光杆扭矩变化规律计算出井筒中任意部位及螺杆泵处抽油杆扭矩的变化情况，也可根据螺杆泵处抽油杆扭矩变化来预测光杆扭矩的变化。为进一步研究地面驱动螺杆泵抽油杆柱的运动特性和采油系统的工作状况提供了理论基础。计算实例表明，该数学模型及其有限差分解法是有效的和稳定的。

KINEMATIC MODEL FOR ROD STRINGS OF SCREW PUMP IN SURFACE-DRIVED PUMPING SYSTEM

Depending on the working characteristics of the surface drived pumping system and the dynamic motion of rod strings, this paper proposes a mathematical model for rod strings and its finite difference solutions. This model can be used to calculate and predict the change in torque of rod string located at screw pump and any locations in wellbore according to the change in torque of polished rod measured on the surface, vice versa. The results of the study provide a theoretical basis for the study of kinematic behavior and working conditions for the surface drived screw pumping system. The calculation examples show that the model and its finite difference solutions are effective and stable.