Experience with Black powder in pipelines on the Norwegian Continental Shelf (NCS) is limited to a few pipelines. The cleaning of one of the pipelines has recently started and the analysis of the dust is on-going. Pipeline cleaning or operational pigging is a part of the maintenance program. The business driver for cleaning the pipeline is to be able to perform an inline inspection and avoid under deposit corrosion in the pipeline.1 First operational cleaning runs after pipeline commissioning gave slurry as the pigging product. Some years later the slurry changed to black powder and caused operational challenges. Due to the low radioactivity (LRA) and the composition of the dust some restrictions for the receiving facility were identified. Modifications at the receiving facilitys have been performed to be able to clean the pipeline in a safe manner. The main business driver for the modifications at the receiving facilities is to ensure an environmentally friendly and safe operation. The dust has not given any problems in daily operation. After the first incident with black powder the Gas Processing Plant installed filter modules to handle the dust in daily operation. Prior to the start of the pipeline cleaning activities, additional filter capacity has been installed in order to ensure a proper protection of the Gas Processing Plant. This paper describes some of the history for the pipeline, the cleaning history, challenges and limitations and the analysis of the dust compared to previous analysis.
This paper discusses the black powder challenge coming out of a Pipeline System containing Rich Gas, fig. 1, transporting dry rich gas from offshore fields to a Gas Processing Plant. The pipeline system consist of an offshore and an onshore part which are connected together at a landfall pig trap station.