Abstract
<jats:p>One of the biggest challenges faced by pipeline owners and operators is corrosion in pipelines, which is most prevalent from the wellhead to the refinery and in storage facilities due to entrained moisture. Current Nondestructive Testing and Evaluation (NDT and E) methods used by pipeline owners and operators, such as Ultrasonic Testing (UT), are effective but are invasive, time consuming, and costly. These customers need an effective technical solution and a more cost-effective approach to inspect their pipelines for corrosion and defects that do not require use of pigs or cause disruption to operations. This document describes the fundamental research carried out to demonstrate the technical feasibility of applying Ultrasonic Mode Imaging (UMI) technology to guided waves for buried pipe inspection, and presents the results obtained, conclusions drawn, and recommendations made. The work performed incorporated the cylindrical geometry of the pipe into the analysis, newly developed data acquisition electronics, and cutting-edge image processing to improve measurement capabilities. The UMI approach has resulted in much higher resolution thickness measurements from guided waves, leading to the tomographic imaging of plate structures. Results have shown that UMI can augment current NDT and E capabilities for difficult-to-inspect piping, including short, hard-to-access lines. The overall benefit to pipeline owners and operators is that the results of this research project provide the foundation for an effective system that could interrogate their pipelines, including long runs of buried piping, externally (non-invasively) while in service and reveal wall thinning (both internal and external) which could affect the safety or integrity of the pipelines.</jats:p>