The basics of the scanning tool incorporate a twin axis system to give the ability to "map" an entire section of tubular over a given distance. All tools map in the axial and rotary axis to give 360 degree complete coverage. In essence the scanning tool is a delivery system as the type of inspection technology fitted to the tools can be interchangeable from compression ultrasonic to eddy current. This gives great flexibility and multiple use of the scanning tools.
The most common type of ultrasonic inspection is compression wave ultrasonics giving wall thickness measurements on a 10x10mm resolution, this can be reduced for higher resolution applications, the compression probes in current use are accurate to 0.2mm.
A recent development with the latest software is the ability to profile the internal surface of the tubular, this method involves capturing the ultrasonic signal from the front face of the probe to the front face of the tubular allowing for the profiling and surface definition of the internal surface to be mapped.
Eddy current can be used both subsea and topside to detect cracking and with the iicorr exclusive system "trec-gauge" for wall thickness. The trec-gauge system can also be used to penetrate up to 50mm of non-ferrite coating giving it the ability to "see-through" coatings and fire protection systems.
Presently the trec-gauge is capable of single point examination on a 40mmx40mm footprint with a sensitivity of 0.5mm.
The standard eddy current system has seen use in varying areas, most recent in the detection of armour wire anomalies within flexible pipe both internally and externally.
iicorr are also leading the way in armour wire hydrogen induced crack detection (HIC) a recent programme of inspection on a recovered flexible pipe allowed the conformation of an eddy current/ultrasonic inspection technique to detect hic on the individual armour wire. |