【摘要】 为应对钻探深度增加带来的井口设备超重载荷挑战，解决超重载荷承载台阶设计校核缺乏统一标准等问题，开展对承载台阶强度的研究。首先，建立考虑摩擦力的斜面台阶力学模型，提出承载台阶剪切失效模型下的计算公式，并对不同设计准则、安全系数和标准下的结果进行对比分析。然后，以万米超深井超重尾管设计的新型带45°斜坡的送入钻杆为例，结合理论分析与弹塑性非线性有限元，进行多种方法求解极限载荷研究，得到轴向的许用载荷和极限载荷，并对钻杆台阶面进行局部应变等评价。研究结果表明：所提出剪切失效公式可用于斜面台阶承载极限载荷计算，建议采用ASME BPVCⅧ-3规定的弹塑性方法进行精细分析，载荷系数取1.8计算许用极限载荷。研究结果为油气井行业中井口设备承载的斜台阶设计与计算提供理论基础与参考。更多还原

【Abstract】 To address the challenges of super-heavy loads on wellhead equipment due to increased drilling depths and the lack of unified standards for the design and verification of bearing steps under super-heavy loads, the strength of bearing steps was studied.A mechanical model of inclined step considering friction was established, then the calculation formula under the shear failure model of bearing step was proposed, and different design criteria, safety factors and standards were compared and analyzed.Taking the newly landing string with 45° inclined slope designed for super-heavy tail pipes in ultra-deep well of ten thousand meters as an example, combined with the theoretical analysis and elastoplastic nonlinear finite element, multiple methods were used to solve the ultimate load.The axial allowable load and ultimate load were obtained, and the local strain of the drill pipe step surface was evaluated comprehensively.The results show that the shear failure formula proposed in this paper can be used to calculate the ultimate load of inclined slope step.It is recommended to use the elastoplastic method specified in ASME Ⅷ-3 for fine analysis, and the load coefficient should be taken as 1.8 to calculate the allowable ultimate load.The research results can provide theoretical basis and reference for the design and calculation of inclined steps bearing by wellhead equipment in oil and gas well industry.更多还原