Understanding The Behavior of Submarine Pipelines Crossing Canyons using Finite Element Analysis

Abstract

This study investigates the design and structural behavior of a large-diameter (28 inch) submarine pipeline crossing an ultra-deep submarine canyon at a depth of 1500 meters. The research combines analytical design based on international standards (ASME B31.8 and DNV-RP) with Finite Element Analysis (FEA) using Abaqus software. The analysis includes wall thickness calculation, on-bottom stability assessment, fatigue screening, and structural responses under environmental loads and internal/external pressures. Results indicate that a pipeline with a 28 mm wall thickness, reinforced by a 52.1 mm buckle arrestor, remains structurally safe and within the allowable stress limits. An axial force of 6.2 MN is required to ensure the pipeline reaches the canyon endpoint while reducing overall stress. However, cross-flow fatigue due to Vortex-Induced Vibration (VIV) necessitates mitigation using VIV suppression devices. The study concludes that suspending a pipeline over a deep-sea canyon is technically feasible when supported by rigorous design parameters and detailed simulations.