Analysis of the Mechanical Response Characteristics of a Suction Pile Wellhead Pre-Tilted Conductor for Gas Hydrate Pilot Production

The use of suction pile wellheads with pre-tilted conductors is expected to help overcome the challenge of high tilting difficulty in offshore gas hydrate extraction. However, structural design and safety control technologies still lack theoretical guidance. In this study, based on Novak’s plane-strain assumption, the potential effects of the pre-tilted conductor on the pipe–soil interaction were considered, along with the influence of working loads and conductor structural parameters. A dynamic vibration model was established to describe the interaction between the suction pile wellhead’s pre-tilted conductor and the surrounding soil, and an analytical expression for the impedance at the conductor’s bottom was derived. Subsequently, parameter analysis was performed using a Python-based computational program (version 3.12.5) to investigate the mechanical response characteristics of the conductor under varying conductor sizes, total lengths, pre-tilted angles, external load magnitudes, and frequency. The results showed that increasing the conductor outer diameter from 32’ to 40’ significantly reduced end displacement by up to 91.24% and bending moments by 30.22%, while shear load decreased by 31.45%, providing important insights for the design of pre-tilted conductors in gas hydrate pilot production. The findings provide theoretical support for the optimal design and safety control technologies of suction pile wellhead pre-tilted conductors.