Offshore Pipeline Inspection
Subsea Pipeline Integrity Assessment with Advanced Ultrasonic Technology
Subsea pipelines transport hydrocarbons across vast distances on the ocean floor, exposed to external corrosion, mechanical damage, and operational fatigue in an environment where repair costs are extraordinarily high. Ultrasonic inspection—both inline inspection (ILI) via smart pigs and external phased array examination—is the primary method for assessing wall thickness, detecting metal loss, and characterizing weld defects in offshore pipeline systems. CCNDT provides ultrasonic instruments and data analysis tools supporting subsea pipeline integrity management programs.
Inline Inspection & Metal Loss Detection
Ultrasonic inline inspection tools (smart pigs) travel through the pipeline interior carried by product flow, measuring wall thickness at millions of points to create a comprehensive corrosion and metal loss map. Direct-measurement ultrasonic sensors provide accurate remaining wall thickness data independent of coating condition, distinguishing internal corrosion, external corrosion, and manufacturing anomalies. This data forms the basis for fitness-for-service assessments and repair prioritization.
- Full-length wall thickness mapping with millimeter-resolution accuracy
- Differentiation of internal vs. external corrosion and gouge damage
- Girth weld anomaly detection and characterization
- Data integration with GIS and pipeline integrity management systems
Girth Weld & Repair Sleeve Inspection
Pipeline girth welds installed during offshore laying operations are inspected using automated ultrasonic testing (AUT) systems mounted on welding carriages. These systems perform real-time volumetric inspection of each weld pass, replacing radiography with faster, safer, and more sensitive defect detection. Repair sleeves, clamp installations, and tie-in welds also require ultrasonic verification to ensure structural integrity before commissioning.
- AUT girth weld inspection per DNV and API specifications
- Real-time defect detection and acceptance/rejection during pipelay
- Repair sleeve and mechanical connector ultrasonic verification
- Tie-in weld and subsea spool piece examination
External Corrosion & Coating Assessment
Despite protective coatings and cathodic protection systems, subsea pipelines experience localized corrosion at coating holidays, field joints, and areas of mechanical damage. Ultrasonic thickness measurement from ROVs or diver-deployed probes provides spot and survey data on remaining wall thickness without removing marine growth or coating. Long-range ultrasonic guided wave screening can rapidly assess extended pipeline sections for gross metal loss from topside or subsea access points.
- ROV-deployed ultrasonic thickness measurement through marine growth
- Coating holiday and field joint corrosion spot surveys
- Guided wave screening for rapid long-distance metal loss assessment
- Cathodic protection effectiveness correlation with UT thickness data
Talk to Our NDT Engineers
Tell us about your inspection target and we will recommend the right ultrasonic solution.