Guided Wave Ultrasonic Testing Provides Rapid Screening For Pipeline Integrity Monitoring

Pipelines are critical components of the oil and gas, petrochemical, and power generation industries, with over two million miles of pipelines being used around the world every day to transport oil and gas products. These pipelines are preferred due to their cost-efficiency but also susceptible to corrosion, compromising their safety and functionality. The integrity of pipelines is a natural concern for pipeline operators, and so the ability to detect corrosion, erosion and mechanical damage in pipes is therefore of significant interest. Traditional methods of detection, such as pigging and crawlers, have been used for many years to inspect pipelines with great success. However, these techniques do have their limitations.

One such alternative is long-range ultrasonic testing (LRUT). Long range ultrasonic testing (LRUT), also known as Guided Wave Ultrasonic Testing, is highly sensitive to most defect types while experiencing low attenuation in most situations, which is ideal for the inspections of a long length of pipework, to identify welds, supports, defects, and other features. GWUT screening is done by wrapping a removable transduction ring around the circumference of the tube/pipe at the desired location, which can be many metres away from the region of interest. Echoes reflecting from these features can then be used to measure their locations and severities (in the case of a defect).

GWUT can be performed on piping that is in operation, insulated and buried, and in areas that are difficult to access such as those at high elevations. The method can therefore save time and money that would otherwise be spent on excavation, insulation removal and scaffolding. It is a global monitoring tool for the detection and analysis of metal loss features, such as corrosion and erosion, in pipes. It is capable of measuring significant lengths of pipe (typically 60m, but up to 350m) from a single point, detecting and locating areas of corrosion rapidly. The technique is capable of detecting 9% and greater cross-sectional metal loss flaws. Once these flaws have been located, conventional inspection techniques are deployed to characterise the defects.

References

Paul Jackson dan Tat-Hean Gan (2007) “The New Age of Pipeline Inspection - Long Range Ultrasonic Testing (LRUT) Update,” Inspectioneering Journal.