基于有限元法的含腐蚀缺陷钻杆剩余抗拉强度分析

The Analysis of Residual Tensile Strength of Drill Pipe With Corrosion Defects Based on Finite Element Method

基于有限元法研究含腐蚀缺陷钻杆的剩余抗拉强度问题,分别讨论轴向腐蚀长度、环向腐蚀长度、腐蚀深度、腐蚀半径等因素对钻杆剩余抗拉强度的影响。研究结果表明:对于均匀腐蚀缺陷钻杆,其剩余抗拉强度受腐蚀深度的影响最大,受环向腐蚀长度的影响次之,受轴向腐蚀长度的影响最小;对于点腐蚀缺陷钻杆,其剩余抗拉强度受腐蚀深度的影响最大,且随着腐蚀半径的增大而增大。与该有限元法相比,依据现行石油行业标准计算所得的钻杆剩余抗拉强度较大,按此强度设计的钻杆存在一定安全风险,因此,设计中应充分考虑不同腐蚀形态的影响。

The residual tensile strength of drill pipe with corrosion defects was studied based on the finite element method.The effects of axial corrosion length,circumferential corrosion length,corrosion depth and corrosion radius on the residual tensile strength of drill pipe were discussed.The results show that for uniformly corroded drill pipe,the residual tensile strength is most affected by the corrosion depth,followed by the circumferential corrosion length,and least affected by axial corrosion length.The residual tensile strength is most affected by the depth of corrosion and increases with the increase of corrosion radius.Compared with the finite element method,the residual tensile strength of drill pipe calculated according to the current oil industry standard is larger,and the drill pipe designed according to this strength has certain safety risks.Therefore,it is suggested that the influence of different corrosion forms should be fully considered in the design.