摘要
采用磁粉无损检测、化学成分分析、力学性能测试、金相分析、显微形貌与能谱分析等方法,对某5-1/2 in整体加重钻杆内螺纹接头的失效原因进行分析。断口宏观形貌和低倍显微镜观察发现存在多个相互独立的裂纹扩展面,且具有疲劳裂纹扩展的贝纹圆弧扩展典型特征;磁粉检测发现多条扩展面的延伸裂纹,微观分析表明这些延伸裂纹与宏观断面一致,沿螺纹齿底轮廓线扩展;化学成分和力学性能实验表明,失效加重钻杆材料的各项性能均符合SY/T 5146—2014标准要求。综合分析认为:整体加重钻杆接头断裂失效的原因是在高压泥浆的冲蚀及施钻时复杂的交变应力作用下,钻杆接头内螺纹齿底萌生裂纹,并快速扩展,从而导致钻杆断裂失效。
The failure reason for a 5-1/2 in integral heavy weight drill pipe joint with internal threads was studied through nondestructive magnetic particle inspection,chemical composition analysis,mechanical property measurement,metallographic analysis,and microscopic morphology and energy spectrum analysis.Macroscopic fracture surface morphology and low-magnification microscopy revealed multiple independent crack propagation surfaces with the typical scallop arc propagation of fatigue crack propagation.Magnetic particle inspection disclosed multiple propagation cracks on the propagation surfaces,which appeared to be consistent with the macroscopic fracture section and extend along the contour line of the thread tooth bottom as indicated by microscopic analysis.Chemical composition and mechanical property experiments showed that all the properties of the material of the failed heavy weight drill pipe met the requirements of the SY/T5146-2014 standard.The comprehensive analysis concluded that the reason for the fracture failure of the integral heavy weight drill pipe joint was that under the erosion by high-pressure mud and the action of complex alternating stresses during drilling,cracks took shape on the tooth bottom of the internal thread in the drill pipe joint and propagated quickly,hence leading to the fracture failure of the drill pipe.
作者
郭涛
艾裕丰
冯娜
李振英
张娟
醋雯月
GUO Tao;AI Yufeng;FENG Na;LI Zhenying;ZHANG Juan;CU Wenyue(CNPC Tubular Goods Research Institute,Xi'an 710077,China)
出处
《石油工程建设》
2022年第2期48-52,共5页
Petroleum Engineering Construction
关键词
整体加重钻杆接头
断裂失效
交变应力作用
冲蚀
integral heavy weight drill pipe joint
fracture failure
action of alternating stress
erosion
