1. Increased pipeline failures
Time, deterioration and corrosion of the world‘s ageing pipeline infrastructure increase the overall likelihood of pipeline failures, according to industry trends. It appears that 65% of all pipeline failures are caused by corrosion. World governments are putting pipeline integrity laws into place that regulate the pipeline business. In the USA, the Pipeline Integrity Bill requires regulated pipelines to be inspected for integrity every five years if transporting liquid, and every seven years if transporting natural gas. Europe will rapidly follow that trend.
2. Deposit formation
The type of deposit that is formed over time in a pipeline is based on the composition of the material that is transported in the pipeline, the pipeline material itself and the level of proper functioning of process equipment upstream. Deposits that one may encounter in pipelines are for example iron sulfate, mineral scales, bacteria, paraffin, black powder, asphaltene, degraded compressor oil, amines and glycol.
2.1. Two ways of cleaning
2.1.1. Mechanical cleaning
The commonly agreed and accepted practice among pipeline owners to remove such deposits is by mechanical pigging, however, it is often hard to determine if this process is sufficiently efficient. When a pig moves through a pipeline, it will feature some carry over of deposit material, causing a thin deposit layer on the inner pipeline wall. Additional mechanical pigging will compact this deposit layer, causing not only nuisances downstream but also initiating a corrosion mechanism. Modern inspection technologies yield superior readings. The readings from these modern intelligent tools are even more accurate, the results are easier to interpret and reruns are not necessary when the pipeline is clean. A typical indication of inefficient pipeline cleaning is when the inspection company reports “sensor lift off” in specific pipeline segments.
2.2.2. Advanced chemical cleaning
The second type of pipeline cleaning, ‘advanced chemical cleaning’, with or without the use of mechanical pigs, removes a greater volume of debris with fewer runs. Brenntag developed advanced chemical cleaning agents (branded N-SPEC®) to provide a more effective and environmentally friendly solution than most current chemical cleaners, such as diesel, toluene or xylene. Rather than dissolving contaminants, the N-SPEC® chemical mixtures:
1. Penetrate between the wall of the pipe and the contaminant;
2. Reduce the adhesive forces of the contaminant;
3. Emulsify the contaminant into a slurry to make it pumpable so that it can be moved forward with a specially designed pig.
N-SPEC products have no effect on any metallurgy thanks to their neutral pH. Secondly N-SPEC cleaning can be done ONLINE.
The N-SPEC cleaning methodology has proven to be very efficient, removing up to ten times more deposit in one run compared to traditional pipeline cleaning chemicals.
3. Financial savings N-SPEC
In summary, N-SPEC® advanced chemical cleaning offers many benefits compared to mechanical pigging that will lead to cost reductions, more reliable integrity checks and increased operating capacity, all thanks to a much cleaner pipeline.