Understanding submarine cable-pipeline crossings on the seabed

Présentation

Durée : 4-6 mois

Context :

Beneath the ocean's surface lies a vast network of submarine pipelines, transporting vital resources, and cables, transmitting essential power and data. These structures are not static, but move due to forces from waves and currents. This motion is particularly problematic where a cable crosses a rigid pipeline, creating a potential point of failure due to repeated contact and wear. While costly and time-consuming mitigation strategies exist, a clear understanding of when these measures are truly necessary is sometimes lacking. Current industry guidelines, largely derived from decades-old oil and gas practices, offer limited specific advice for modern, lighter fiber-optic cables crossing existing pipelines, leaving a significant gap in design and operational guidance.

In principle, each element of the physics is well understood—including contact forces between the cable and seabed (or pipeline), cable stiffness, and the hydrodynamic forces acting on the cable. However, the combined system is complex, and the hydrodynamics must account for the random nature of waves. For a cable covered in a Uraduct©, the expected behavior is that the cable remains stationary until hydrodynamic forces overcome static friction, causing a slip along the surfaces. Alternative pipeline crossing methods to completely avoid this behavior are often prohibitively expensive, highlighting the need to thoroughly understand the efficacy and physics of the Uraduct© solution.

The primary goal of the internship is to quantify the number of movement cycles and the total distance traveled over a given lifetime (measured in years) under realistic operational conditions. This will involve a detailed literature review to assess previous work in this field, followed by a numerical study to estimate wear and determine the necessity of further investigation. Once the physical problem and engineering challenges are clear in a simplified setup—for example, using a small Python script—the project will progress to more advanced numerical modeling techniques (e.g., testing finite-element solutions or utilizing industry tools). The final deliverable will be a self-contained tool capable of predicting behavior as a function of site conditions (e.g., cable/pipeline diameter, material properties, seabed characteristics, water depth, and wave/tidal profiles).

Profile:Master's student in fluid mechanics, scientific computing, and/or mathematics interested in research in these fields

Internship location:Saint Venant Hydraulics Laboratory (École des ponts et chaussées, EDF R&D), Chatou, France

Length of internship:4-6 months

To apply, please send your CV and a letter of motivation to Jeffrey Harris (jeffrey.harris@enpc.fr).