Non-Destructive Testing Practices in Nigerian Oil and Gas Fabrication Yards: A Professional Competency Assessment

This study assesses the professional competency levels and operational practices in non-destructive testing (NDT) applied at oil and gas fabrication yards in the South South geopolitical zone of Nigeria. Non-destructive testing is fundamental to the quality assurance and integrity verification of welded pressure vessels, structural components, and piping fabricated for Nigeria's oil and gas sector, and the professional capability of NDT practitioners directly affects the reliability of inspection outcomes. A descriptive survey design is employed, with a structured competency questionnaire administered to 80 practising NDT technicians and inspectors at fabrication yards in Port Harcourt, Warri, and Eket. Competency domains assessed include theoretical knowledge, procedural application, equipment calibration, and defect characterisation across the NDT methods of radiographic testing, ultrasonic testing, magnetic particle testing, and dye penetrant testing. Findings reveal that only 38 percent of surveyed technicians hold current PCN or ASNT certification at Level II or above, while the majority rely on employer-issued training certificates of variable standard. Ultrasonic testing competency levels are the weakest across the sample, with significant gaps in phased array UT application knowledge. The study concludes that a structured national NDT certification framework aligned to ISO 9712 is urgently needed for Nigerian fabrication industry practitioners. Keywords: non-destructive testing, fabrication yard, competency, oil and gas, South South Nigeria.