|ROCK DENTS ARE common defects found in onshore buried pipelines. The pipeline operator becomes concerned if such dents are diagnosed in its pipelines since dents pose a threat to the structural integrity and safety of the pipeline. Current pipeline standards and codes provide dent-assessment guidelines based on dent depth, which is usually limited to 6% of the outer diameter of the pipe. These codes and standards recommend removing a dent if its permanent depth exceeds the limit of 6%. Pipeline operators may use their own guidelines to decide whether or not a dent needs to be repaired or replaced. However, repair and replacement operations for a dent are costly affairs since they require mobilization of maintenance crew and heavy equipment at the location of the dent which may not have an easy access. In addition, the pipeline operation may need to be pushed for an unscheduled and undesirable shutdown, resulting in a loss of revenue.
This project was undertaken to develop a cost-effective and less-troublesome dent-management approach called ‘do-a-little’ approach that will allow the pipeline operators to strategically delay the repair and replacement operation of a dent while still ensuring the structural safety of the pipeline.