Recent advances in inspection of drilling pipes by ultrasonic methods

Until recently, inspection of the body of used drill pipe for pits, transverse fatigue cracks and wall loss was performed by a traditional combination of magnetic flux leakage (MFL), compression wave ultrasonic, and mechanical outside diameter (OD) gaging. However, with existing drill pipe sitting on the ground for many years , and a renewed awareness among oil companies to minimize drilling costs, the need for upgrading the nondestructive evaluation (NDE) equipment for used drill pipe has arisen. So , this article outline the time of flight diffraction “TOFD” for sizing drilling pipe defects which is based on the time of flight of the diffracted echo that is generated when a longitudinal wave is incident on a crack tip. This method provides high speed inspection, high sizing reliability and low rate of false defect indications and, if applied correctly, will improve the defect detection and sizing capabilities for non-destructive inspection which is required in order to ensure the reliable operation and life extension of drilling pipes.

کلیدواژه ها:

TOFD ، drilling pipe ، defects