In-line inspection of unpiggable pipelines; a challenge and a solution
Over the years, pipelines remain to be the safest means to transport petroleum products from wellheads to tankers. However, the presence of external and internal corrosion threatens their integrity.
Regular High Resolution In-Line inspection (pigging) monitors and defines the progress of corrosion using applicable technologies (MFL, TFI, Eddy Current, UT, UTCD, EMAT, etc.) for the various corrosion processes.
Regular In-Line inspection tools can inspect these cross-country pipelines designed to ASME standard and equipped with pig traps. Many pipelines however do not have these traps (old, short, small in diameter) and are now considered ”unpiggable”. Economic consideration was the main reason for not equipping pigging facilities, regretfully.
The selected cases prove that unpiggable seems to be an opinion rather than a fact. Pipelines inspected are:
1. 8 and 10inch flow lines with 3way ball pig valves and back to back 1.5D bends.
2. 48inch size tanker loading lines without traps.
3. A 38inch size, 320kms long gas line with excessive dust.
4. A 36/42inch size pipeline
Even the Pipeline Research Council International (PRCI) discourages using the word “unpiggable” and LIN SCAN agrees with that totally. As we have proven to pig unpiggable lines, often, we suggest that you tell us what needs to be done and will find a way of how to do it.
Every day, LIN SCAN demonstrates its commitment to excellence for solving clients’ challenges in the operating environment. LIN SCAN lifted the level of In-Line Inspection from leak detection to identifying the risk of leak development.