Pipeline Challenges: Unpiggable Lines

Pipeline development history is short and fast. The technology as increased faster than new crews could be trained or new materials produced, and as a result, much of the currently used pipeline network is not necessarily up to date. The infrastructure continues to change due to fuel prices, technology, and construction methods. It is an industry wide challenge to continually maintain pipelines and upgrade to newer technology so that future inspections are easily conducted.

Subsea development has increased dramatically in recent decades, which is very difficult in terms of inspection. Pipelines of production flow as well as other field pipelines lack launcher/receiver facilities for the entire section of pipe. Pipeline inspection vessels must be deployed to inspect the length of the pipeline, which is very costly. Those lines designed with PIGS, or Pipeline Inspection Gages, are much more cost effective to inspect, so the challenge is converting the lines previously laid. As you might imagine, inspection is not only a challenge for these offshore pipelines, but also for all older subterranean pipes.

Refinery pipelines are another challenging example of "unpiggable" lines. There are so many difficult factors when inspecting these pipelines and updating them for future inspection. Problems associated with casings, flow lines, j-tubes, and risers are just to name a few. Because of new regulations and code requirements, companies and their engineers are concentrating on investigating these older lines, but that is not the only reason. It is simply cost prohibitive not to perform extensive inspections for smaller pipeline companies such as Western Pipeline Corporation. The cost of a single spill will far outweigh the cost of inspecting every pipeline.

Though the technology necessary to inspect unpiggable pipelines varies depending on the location, new more cost effective solutions are developing. There are now external ultrasonic testing methods, corrosion mapping, NDT, and even internal systems available. Internal systems basically consist of free swimming PIGs connected by an umbilical tube that propels itself inside a pipeline. This free moving inspection gauge prevents the need to remove soil, rock, or coating, thus it is fairly cost effective. Unlike the traditional PIG, it actually gauges pressure through its own internal pumps rather than through the pipeline.
Companies and regulating bodies alike are working hard to solve the challenges of the shifting pipeline infrastructure, and the curve is continuing to move up. It is not a bad thing that the United States has the oldest and most complicated pipeline network, but it does make for some interesting problem solving issues as times change.

About the Author: Bob Jent is the CEO of Western Pipeline Corporation. Western Pipeline Corp is a successful, private independent producer of oil and natural gas.