抽油杆柱磨损分析与安全性评价

Wear Analysis and Safety Assessment of Sucker Rod

杆柱使用寿命方面,传统的计算方法通过预测磨损量来计算杆柱的疲劳极限,没有考虑井下复杂情况以及预测参数的不确定性,计算结果不能很好地反映杆柱工况以及安全性。针对这一问题,建立基于GA-SVM和蒙特卡洛模拟的抽油杆柱磨损分析与安全评价模型。根据抽油杆柱受力分析,获得杆柱井下受力情况,利用GA-SVM建立井下影响因素与抽油杆柱磨损率之间的映射关系;充分考虑井下参数的不确定性,利用蒙特卡洛模拟法计算抽油杆柱的安全可靠程度,并结合安全等级进行寿命分析。分析结果可与现场实际情况一致,同时,寿命计算具有较高的预测精度。该方法具有一定的现场适用性,能够为现场技术人员提供杆柱磨损与安全分析处理依据。

In the aspect of rod service life , the traditional method calculates the fatigue limit of the rod by pre-dicting the wear amount without considering the downhole complexity and the uncertainty of the predicted parame-ters , thus, the calculated results can not accurately represent rod condition and safety. In view of this, the wear a- nalysis and safety assessment model of sucker rod has been established based on GA - SM and Monte Carlo simula-tion. According to the force condition of the sucker rod through force analysis, the mapping relation between the downhole influence factor and the wear rate of the sucker rod has been established using G A - SVM . Taking the un-certainty of the downhole parameters into account, and the Monte Carlo simulation method has been used to calcu-late the safety and reliability of the sucker rod. The life analysis of sucker rod has been carried out according to the safety grade. Field analysis shows that the method has field applicability and could provide sucker rod eccentric wear and safety analysis data for field technicians.