Diakont Advanced Technologies was commissioned to assess the integrity of a natural gas pipeline that was partially buried under an urban area on a major North American pipeline. The company used a reduced size robotic crawler to successfully navigate a 10 in. pipe. The size of this pipe has previously been a limitation, making it ‘unpiggable’ using other ILI methods.
Designated as a high consequence area (HCA) due to being located in a densely populated area, this section of pipeline had never been inspected. Low flow, its narrow 10 in. internal diameter (ID), and its characteristics (tight bends, plug valves etc.) made the pipe unsuitable for traditional smart pigging. However, the United States’ federal Pipeline and Hazardous Materials Safety Administration (PHMSA) regulations require specific integrity management programs in HCAs.
The pipeline’s inspection challenges could have forced its operator to replace an entire quarter of a mile length of pipe if they could not inspect the line effectively and on schedule. The technology gap between the inspection requirements and the available tooling forced the industry work with pipeline service vendors to develop a suitable solution.