Given pipeline and feature geometry variability, an ILI technology with robust reporting and feature characterization is desirable. Phased array ultrasonic testing offers significant advantages over inspections performed with monolithic sensors, primarily due to its high degree of flexibility. Phased arrays can be configured at the software level, enabling a single inspection tool to operate under varying sensor parameters, such as aperture size and incidence angle. In addition to the high configurability, a single phased array inspection provides complementary depth sizing information, including both amplitude based and time of flight based measurements.

Pulse Echo stands out as the standard technique for feature detection, as it is effective across a wide range of defect types. However, its depth sizing performance degrades for features with complex geometries or significant depth. In such cases, pitch and catch provides supplemental detection and depth sizing, even for non radial features and deeper indications. For deep defects, where accurate risk assessment is critical, tip echo measurements offer the most accurate depth sizing.

Pipeline geometry variability can further affect detection and depth sizing performance, particularly in the vicinity of long seam welds. A key advantage of phased arrays is the ability to use multiple inspection angles, as the optimal angle depends on the properties of the weld. Additional geometric effects, such as peaking in long seam welded pipes, can further alter the effective incidence angle from the nominal design value. Thanks to the adaptability of phased arrays, even targets as challenging as tilted cracks in peaking can be detected with a phased array tool. This detection is possible by leveraging two benefits of phased arrays. First, the radial shot of the phased array allows the sizing of the peaking, providing a mapping of the pipe. Then, the incidence angle can be chosen to counteract the presence of peaking.