Intelligent Assessment Method for Instability Probability of Subsea Wellhead in Marine Environment

Abstract With the decline of onshore petroleum resources, domestic petroleum exploration is continually progressing towards deep water. The subsea wellhead is an important component of deep water petroleum extraction systems. It is exposed to various external loads such as waves, currents and soil resistance, which can potentially lead to tilting and subsequently trigger catastrophic events like wellhead collapse and blowout. In order to enhance the reliability of wellheads, this study has established a simulation analysis model of subsea wellhead systems to study critical factors influencing lateral stability. By integrating simulation with machine learning, this study has formulated a probabilistic assessment method for evaluating the instability of subsea wellheads, assessing the instability probabilities under varying marine conditions. The results show that the bending moment and von Mises stress are critical limiting factors for the safety of subsea wellhead. As the length of riser increases and marine conditions deteriorate, the probability of wellheads instability rises.