During the subsea well construction and workover, a subsea well is connected to the drillship through the blowout preventer (BOP) and the drilling riser. Environmental loads acting on the drilling riser and the drillship are transferred to the wellhead, conductor, and casings, which can cause fatigue issues at critical points such as at the casing couplings. The main function of a subsea wellhead system is to perform the interface between the BOP and the well, ensuring its integrity throughout its operational life. Factors such as the increase in the weight and height of the BOP on 6th generation platforms contributed to the increased risk of failure due to fatigue. The system in this work is represented by a 3D finite element model including internal cement, conductor, and surface casings. Although simplifications were adopted in the modeling, the essence of the well physical behavior remains. The work addresses the influence of the wellhead stick-up on the maximum stress in the conductor below the seabed, comparing analyses of two wellhead stick-up and including horizontal displacement resulting from the integration of the platform/riser dynamics. These horizontal loads are transferred to the top of the wellhead system as a bending moment and shear force. A time series containing riser horizontal loadings is utilized to obtain the von Mises stress. This information is used to count cycles with the rainflow counting technique. The number of cycles resulting for the two wellhead stick-up is compared and demonstrates how wellhead stick-up can be influenced by an increase in dynamic loads acting on the wellhead top. An influence can be observed on the maximum stress point of the conductor located below the seabed. From these results, it was possible to conclude the wellhead stick-up can influence the depth of a critical point in the conductor below the seabed.

在海底井施工和修井过程中，海底井通过防喷器（BOP）和钻井隔水管与钻井船相连。作用在钻井隔水管和钻井船上的环境载荷会传递到井口、导体和套管，这可能会导致关键点（例如套管接头处）出现疲劳问题。海底井口系统的主要功能是执行 BOP 和井之间的接口，确保其在整个使用寿命期间的完整性。第 6 代平台上防喷器的重量和高度增加等因素导致疲劳失效风险增加。这项工作中的系统由 3D 有限元模型表示，包括内部水泥、导体和表面套管。尽管在建模中采用了简化，井物理行为的本质仍然存在。这项工作解决了井口翘起对海床下方导体中最大应力的影响，比较了两个井口翘起的分析，包括平台/立管动力学集成产生的水平位移。这些水平载荷以弯矩和剪切力的形式传递到井口系统的顶部。使用包含立管水平载荷的时间序列来获得 von Mises 应力。此信息用于使用雨流计数技术对周期进行计数。比较了两个井口翘起的循环次数，并展示了井口翘起如何受到作用在井口顶部的动态载荷增加的影响。可以观察到对位于海床下方的导体的最大应力点的影响。从这些结果可以得出结论，井口粘滞会影响海床下方导体中临界点的深度。