Abstract
The pipeline has been in operation since 1985 and transports a gas rich on hydrocarbons but low in water dew point, within the specifications for dry gas. A cleaning program was identified from the start.
In the beginning there were no operational pigging challenges, black slurry was cleaned out of the pipeline approximately every two years. After twenty years in operation the slurry suddenly changed to powder, causing operational powder issues, in addition to the environmental challenges with the powder itself.
The powder is both pyrophoric and classified as LRA (Low Radioactive). This change in the pigging residue was the start for many years of studies, modifications, planning of cleaning the pipeline, performing the long cleaning operation and in the end – inspection of the pipeline to verify the condition.
This paper tells the story from the powder first was discovered, the actions taken to manage the powder, the cleaning of the pipeline and the recent inspection results.
