Bidirectional 12-in – Subsea Pipelines
Dexon was tasked with inspecting two 12-inch, 1,000-meter subsea pipelines transporting jet fuel and diesel from a jetty to a sea berth in Asia. The key challenge was to complete the inspection with minimal downtime, without installing a costly offshore receiver, and while navigating tight bends in the pipeline.
)
Overview
Key challenge:
Inspect two 12-in. subsea pipelines supplying jet fuel and diesel to tankers, while minimizing downtime and avoiding the installation of a costly offshore receiver.
Project Details
• Length: 1000 m
• Diameter: 12-in.
• Type: Subsea jet fuel & diesel jetty to sea berth pipelines
• Inspection Medium: Jet fuel
• Location: Offshore/onshore
• Continent: Asia
• Tool: UT-MC Ring, a high-resolution tool specializing in corrosion detection
Challenges & Solutions
Challenge 1:
• Standard UT-MC Ring not configured for bidirectional runs in tight bends
Solution:
• Adapted the compact UT-MC Ring with a joint-free design so the tool would not risk getting stuck on return
• Redesigned & condensed electronics to fit into shorter body
• Retained high-resolution capability (±0.3 mm)
Challenge 2:
• Lack of a launcher and receiver
Solution:
• Designed and fabricated a bespoke launcher onshore, avoiding the need for a receiver at the sea berth—installing a receiver seaside would significantly increase the costs for the operator
Challenge 3:
• High downtime costs due to tight shipping schedules
Solution:
• Performed the inspection bidirectionally in just over two hours, minimizing operational disruption and ensuring continuous fuel supply.
Conclusion
Dexon successfully inspected two critical 12” subsea pipelines with a customized bidirectional solution, completing the run quickly and safely while meeting the client’s strict scheduling and quality requirements.
By adapting the UT-MC Ring and designing a bespoke launcher, Dexon minimized downtime, reduced costs, and delivered actionable integrity data.