Pipelines & subsea

The pipeline that pops out of the seabed

Upheaval buckling of a buried subsea pipeline · narrated

Duration

1:48

Year

2026

The case

A 16 in subsea crude line at 100 bar, buried under at least 0.6 m of loose sand, with a hump 20 cm high and 60 m long. As it heats up, the blocked expansion turns into compression that pushes the pipe upward at the hump. At 64 °C, short of the 70 °C design temperature, the sand can no longer hold it and the pipe snaps upward. Concrete mattresses raise the onset to 70.8 °C with 2, 76.6 °C with 4 and 81.0 °C with 8; beyond 8 the model gives the same result. What matters is which metres you hold down.

Topics

• Upheaval buckling
• Pipe-soil interaction
• Narrated explainer

Basis. Generic synthetic case built for this piece. No client data. Not a design verification.