At the start of welding activities in oil and gas projects, high welding rejection rates (WRR) are often reported. This is a cause for concern to companies because welding defects that are not identified nor corrected can have serious consequences, such as on asset integrity, cost of rework, and schedule impact. Therefore, the quality organizations immediately investigate the different causes and recommend solutions which eventually contributes toward lowering the WRR.
Based on recent field studies conducted in oil and gas projects using the Six Sigma methodology, high WRRs are caused by many factors, including but not limited to the following:
1. New and inexperienced welders with poor welding techniques.
2. Poor environments surrounding the welding activities.
3. Discrepancies and inaccurate data in the welding tracking system (WTS).
These contributing factors can be reduced and eliminated by implementing a strong welding inspection and control program with the following recommendations:
1. Screen for qualified and experienced welders with a proven successful welding history before starting the welding.
2. Test the welders on-site before actual production welding.
3. Implement an encouragement scheme for welders by having frequent toolbox meetings and presenting awards for the best welders according to the lowest rejection rates.
4. Assess the WTS constantly to prevent any inaccurate data.