It is extremely important that a pipeline be in clean condition prior to an In-Line Inspection (ILI) run. Loose or adhered deposits and scale can cause a range of issues from sensor “lift off” that causes the tool sensors to be ineffective and unreliable to a pipeline becoming plugged with deposits in front of the inspection tool. These issues can require costly repeat runs of the inspection tool or, in the worst case, the tool can become stuck in the pipeline and need to be cut out to remove it.
With proper line preparation prior to running an Inspection tool we can avoid costly tool recovery and tool re-run expenses. The key is to understand the type of debris we may encounter when designing an effective cleaning program.
Our client had been installing new pipelines and had issues with In-Line Inspection tools becoming clogged with ferrous debris that caused skewed sensor data and sensor “lift off”. These were base line inspection runs performed after hydro test. The fluids used in hydro test tend to be recovered and reused over and over and can be quite dirty. There is also a lot of ferrous material left behind in the construction process ranging from grinder filings to hardware.