【摘要】 对某油田发生的钻杆接头纵向开裂事故进行了系统调查,对钻杆接头裂纹宏观形貌和微观形貌进行了分析,对开裂钻杆接头和未开裂的钻杆接头材质进行了对比。结果表明：钻杆接头纵向开裂原因是摩擦裂纹引起的,摩擦裂纹的原因主要与井眼全角变化率偏大有关。更多还原

【Abstract】 Analyses of longitudinal cracks of tool joints were performed based on field background search, macro and micro crack morphology analysis and material testing of both cracked and not cracked tool joints.It is concluded that the tool joint failure was caused by friction which resulted from severe overall angle change rate.更多还原