某井S135钢级钻杆断裂原因  

Fracture causes of S135 steel drill pipe in a well

作　　者：陈猛[1] 欧阳志英[1] 余世杰[1] 舒志强[1] CHEN Meng;OUYANG Zhiying;YU Shijie;SHU Zhiqiang(Shanghai Hilong Oil Tubular Goods Research Institute,Shanghai 200949,China)

机构地区：[1]上海海隆石油管材研究所,上海200949

出　　处：《理化检验（物理分册）》2022年第5期48-53,共6页Physical Testing and Chemical Analysis(Part A:Physical Testing)

基　　金：上海市优秀技术带头人计划(19XD1430400)。

摘　　要：某井起钻时,井底一根101.6 mm(外径)钻杆在距离公接头台肩面约1.1 m处的管体上发生了断裂。采用宏观观察、化学成分分析、力学性能测试、金相检验、断口分析、钻杆受力计算及有限元模拟分析等方法对钻杆的断裂原因进行了分析。结果表明:断裂钻杆的屈服强度不符合API Spec 5DP—2009标准的要求;钻杆在通过不规则的井眼时发生了严重的弯曲压扁变形,导致钻杆失稳断裂;解卡过程中,断点附近反复的拉压载荷使得该区域产生了包申格效应,导致屈服强度进一步下降,加速了钻杆的断裂。A 101.6 mm(outside diameter)drill pipe at the bottom of a well fractured about 1.1 m from the shoulder of the common joint platform.The fracture causes of the drill pipe were analyzed by means of macroscopic observation,chemical composition analysis,mechanical property test,metallographic examination,fracture analysis,drill pipe force calculation and finite element simulation analysis.The results show that the yield strength of the fractured drill pipe did not meet the requirements of API Spec 5 DP—2009 standards.When the drill pipe passed through an irregular borehole,it had serious bending and flattening deformation,resulting in the instability and fracture of the drill pipe.In the process of unlocking,the repeated tensile and compressive loads near the breaking point caused the‘Bauschinger effect’in the region,which led to the further decrease of yield strength and accelerated the fracture of drill pipe.

关 键 词：S135钢级钻杆 断裂 压扁变形 有限元分析 包申格效应 

分 类 号：TE931[石油与天然气工程—石油机械设备]