基于偏磨分析的杆柱磨损寿命预测模型

Prediction model of rod wear life based on partial-wear analysis

针对杆柱发生磨损后的寿命预测问题,基于井下抽油杆与油管随时间磨损的特点,应用ΠΡΟΗΝΚΟΒ提出的磨损计算公式,推算出杆柱在大狗腿度处以及杆柱组合下部受压部分的磨损厚度和磨损面积与时间的关系,并根据抽油杆横截面积减小造成抽油杆磨损处的应力增加的原理,建立了一套可以预测杆柱寿命的模型。该模型可以在已知井眼轨迹和杆柱结构的前提下预测抽油杆柱的断脱位置和断脱时间。通过实例计算验证了该模型的准确性,并通过该模型分析了旋转井口有助于延长抽油杆柱磨损寿命的原理。

A model was established to analyze and predict effectively the wear life of rod.It is considered in this model： the two main reasons for partial-wear： borehole curving and rod blending under pressure in the down stroke.A calculating formula suggested by ΠΡΟΗΝΚΟΒ was used to evaluate the increase of abrasion thickness of rod with time,and the failure position and time were estimated in accordance with the increase of stress with the decrease of residual cross-section area at the point where the wear was worst.The comparison between the model result and the spot data was used to prove the reliability of this model.The principle that the revolving wellhead could retard the progress of wear was interpreted through the calculating result made by this model.