ABERDEEN, UK – Sonomatic, a market leader in the provision of advanced automated ultrasonic inspection services, has developed a screening technique which can be used to verify the integrity of piping or to inspect regions of restricted access, such as pipe supports. The system uses shear horizontal (SH) waves produced by electromagnetic acoustic transducers (EMATs).
Sonomatic has pioneered the use of SH-EMAT for screening inspection. In comparison with conventional EMAT systems, the SH-EMAT system produces much clearer signals which are easier to interpret, the signals are also less attenuated by any fluids surrounding the specimen. Unlike piezo-electric transducers, EMATs do not require couplant and can tolerate an air gap between the bottom of the probe and the specimen. For this reason, EMATs are less sensitive to surface condition than other ultrasonic techniques. The system can be deployed using a hand scanner for topside use or using a magnetic crawler for subsea pipeline inspections (up to 500 m).
The system uses two EMATs separated circumferentially but in the same axial location. Signals are transmitted around the entire circumference of the pipe. The EMATs are moved along the pipe collecting information on the entire circumference at each axial location. As a result, this technique can rapidly provide information on the condition of a pipe. In areas of restricted access, such as pipe supports, the pipe can be scanned in situ without being lifted. For example, during a recent deployment, this technique was able to scan 24 areas of restricted access in less than four hours, this in comparison radiography which had previously required 4 hours to scan a single location. Following an inspection, the recorded signals are processed further, using algorithms developed by Sonomatic, in order to highlight any areas of minor degradation.
As part of the technique validation, Sonomatic participated in blind trials through the HOIS Joint Industry Project. During this trial, Sonomatic’s technique achieved 100% detection and 0 false calls for 21 pipe specimens. The system has been proven in the field, with application across a number of locations internationally, scanning pipes with a thickness of up to 18 mm and diameters up to 30”. Sonomatic is continuing to develop the system and probes are currently being designed within Sonomatic which will allow greater range of thickness to be inspected. The transducers are being manufactured internally by Sonomatic’s probe department.
Sonomatic is a market leader in the development and provision of automated non-destructive ultrasonic inspection and related integrity services for the oil and gas, power generation and defence sectors. It has operational bases in Aberdeen and Warrington in the UK, Perth and Brisbane in Australia, Abu Dhabi and Muscat in The Midde East, Johannesburg, Secunda and Vanderbijl Park in South Africa, and North Carolina and Houston in the US.