钻柱失效机理及其疲劳寿命预测研究

RESEARCH ON THE FAILURE MECHANISM AND FATIGUE LIFE PREDICTION OF DRILLPIPE

林元华 罗宏志 邹波 施太和 翁小红 李润方

Lin Yuanhua Luo Hongzhi Zhou Bo Shi Taihe Weng Xiaohong Li Runfang

西南石油学院油气藏地质及开发工程国家重点实验室, 四川成都 610500 胜利石油管理局, 山东东营 257000 新疆石油管理局, 新疆库尔勒 841000 重庆大学机械传动国家重点实验室, 四川成都 610500

钻柱工作条件恶劣,尤其在狗腿或弯曲井段时,较大交变弯曲应力常造成钻柱疲劳破坏,计算钻柱疲劳寿命可以为钻柱使用和管理提供依据。因此,在定性分析钻柱失效机理的基础上,对钻柱进行了三轴应力分析,并提出了钻柱疲劳寿命的计算模型,该模型可用于无裂纹钻杆和有裂纹钻杆疲劳寿命预测。算例表明,该方法对钻柱疲劳寿命的估算较为合理,符合工程实际。

The working condition of drillpipe is very serious, especially in the dogleg or build section. Large alterative bending stress gives rise to the fatigue failure of drillpipe. Calculation of the fatigue life of the drillpipe can give some guidance for the use and precaution of drillpipe failure. As a result,in this paper, the three - axis stress has been analyzed based on the mechanism of fatigue failure of drillpipe, and a model for the calculation of fatigue life of drillpipe is proposed, which can be used for the prediction of fatigue life of crackled or noncrackled drillpipe. Results of example show that the model is reasonable and coincident with the field data.

10.3969/j.issn.1000-7393.2004.01.006