The oil and gas pipeline industry depends on “Pigs” (pipeline integrity gauges) to verify pipelines. They help avoid leaks, fractures and costly unscheduled service interruptions. As massive new oil and gas pipeline construction continues in the US and as existing pipelines get older the pig business is becoming more valuable. But like anything else, they aren’t perfect; and pigging experts and pipeline operators are motivated to make them better. Today we continue our analysis of the pig business with a look at what some of the movers and shakers are doing to support new demands and challenges in this booming industry.
In the first part of this series, “WOOO – PIG – SOOIE!” – The Business of Pipeline Integrity” we talked about how oil and gas products have been traveling through pipelines for about 100 years. Pigs have been responsible for keeping pipelines clean and operational since the 1940s, when WWII emergency pipelines (carrying crude and refined products overland to avoid submarine attacks) needed a way to eliminate the buildup of contaminants. Pigs are by far the most dependable pipeline integrity technology today and account for over 90% of all petroleum liquid pipeline inspections (the other 10% is hydro pressure testing and direct assessment). Pigging is big business and while most manufacturers are enjoying the fruits of the current energy boom, they also have plenty of challenges. Companies like TD Williamson, Girard, Enduro, and Inline Services are aggressively competing to provide the best and most effective pig and/or pig support products out there.
More Big Pig Business
Included in the larger pig industry family are pipe manufacturers, pipeline construction companies, pipeline operators, pipeline service providers, state and federal regulators and pig manufacturers. In recent years, there has been increased scrutiny and regulation of the pipeline business for environmental and public safety reasons. Market players need to pay attention to these concerns at the same time as they keep a tight lid on costs.
In addition to pig cleaning and gauging service, and smart pigging or Inline Inspection (ILI) pigs also require specialty support products and services to make them work. These include pig traps (where the pig goes into and out of the pipe), launching and receiving stations, and pig trackers and signalers. Third party suppliers that are not pig manufacturers typically provide these ancillary services.
Inline Services and Girard are top cleaning and gauge pig manufacturers. T.D. Williamson and Enduro Pipeline Services produce pigs that pretty much cover the gamut; cleaning, gauging, batching, and smart pigs that include varying specialized design and technologies. The latest smart pig technologies include Deformation (DEF) that is specific to finding dents, Magnetic Flux Leakage (MFL) specific to corrosion, and Multi Data Set (MDS) for multiple discoveries like dents, corrosion and seam defects. New ultrasonic tools are proving even better than traditional MFL tools for finding corrosion and cracks. Unfortunately, they can only be run in a liquid medium pipeline such as oil, water or diesel – not in a gas pipeline. TD Williamson and others have also been working on perfecting Electro Magnetic Acoustic Transducer (EMAT) technology, which can be run in gas lines. We should see these in the marketplace soon.
Top Pigging Challenges
The following are some of the industry’s top challenges:
- Pigging is not cheap: An industry expert shared this typical example to illustrate: To chemically clean (cleaning pig) a 24” 15 mile gas pipeline would cost between $210,000 - $250,000 plus a disposal fee of $25,000 - $30,000. This cleaning is typically done before an ILI smart pig operation that costs another $100,000. So the total pigging cost on that 15 miles of pipeline would be $335,000 - $380,000 or roughly $35,000 per mile. To get an idea of how much money can be spent on pigging you can extrapolate that $35,000/mile number to arrive at $59 billion to run this standard pigging operation on all US pipelines one time.
- Pigs are labor intensive: Each pig can only handle a few miles at a time on average. Also, they can be quite messy and generate problems for downstream equipment if not filtered properly. They are generally used in “in-service” pipelines necessitating lots of careful planning for operations. Each time a pig is launched, it can take two or three man hours of preparation prior to each launch and some pigging projects require 50-60 launches or more. A typical pigging system requires the opening and/or closing of at least three major valves, the draining and venting of a barrel, and the opening and closing of a closure door. In some cases, it can take up to four hours for a single crew to load and launch a single pig (and that doesn’t even include the time to receive and remove the pig). Beyond the time and labor constraints, there are also wear and safety considerations. And of course, should there be any problems with the process, all of this must be done again.
- Pigs do not catch every glitch in every pipe: While smart pigs do spot corrosion and potential areas of concern, they can miss pinholes and/or corrosion that is less than 1” in size. And if a cleaning pig does not clean the pipe before the smart pig does its thing, those “misses” multiply. Cleaning pigs generally go hand in hand with smart pigging programs.
- Not all pipes are piggable: Many pipelines or parts of pipelines out there simply can’t accommodate pigs at all. These are often referred to as “unpiggable” or “not-so-piggable” pipe. There are several reasons for a pipe to be considered unpiggable, including: (1) it has no access for the pig; (2) it has multiple diameters; (3) it has impassable valves or fittings, or valve restrictions; (4) the pipe bends; (5) there are external pipe defects, and/or (6) there is a buildup of contaminants preventing the pig from moving. Of the 2.4 million miles of pipeline in the U.S., roughly 30% falls into the unpiggable category and another 10% are considered “difficult to pig”.