High-Temperature – Subsea Pipeline

Key challenge: 
Inspect a subsea pipeline at risk of circumferential cracking after mechanical displacement, despite tight launcher constraints and high internal temperatures (up to 90°C), with no off-the-shelf tool available. 

Project Details 

• Length: 300 m 

• Diameter: 12-in. 

• Type: Subsea water injection pipeline 

• Inspection Medium: Treated seawater 

• Location: Offshore 

• Continent: South America 

• Tool: UT-CD Hawk, specializing in high-resolution circumferential crack detection & sizing. 

Pipeline Challenges & Solutions 

Challenge 1:  

• Reducing tool length from the standard size of 4.6 m to 1.3 m to fit short launcher 

Solution:  

• Expanded space in the body’s shell 

• Redesigned & condensed electronic parts 

Challenge 2:  

• High operating temperature of 90°C, well-beyond conventional ILI tool specs 

Solution: 

• Added heat sinks & liquid coolants 

• Redesigned electronic parts using heat-resistant alternatives 

• Conducted thorough heat tests prior to mobilization 

Challenge 3:  

• Unique pipeline fabrication and possible crack defects 

Solution:  

• Fabricated spools in-house following methods provided by the operator 

• Added EDM notches in a range of sizes to recreate expected defects 

• Inserted custom spool in pipeline at test yard to test the tool as close to real conditions as possible 

Conclusion 

The successful run delivered full coverage and accurate flaw detection, allowing the operator to return the pipeline to full pressure, set a baseline for long-term crack monitoring, and calculate a precise remaining life assessment.