Cleaning pigs are an integral component of oil and gas pipeline integrity and maintenance. In order to keep pipelines free of debris and functioning safely and efficiency, these foam, urethane and metal-bodied pigging products have scrapers and brushes to remove wax, liquids and other buildup inside the pipe.
North American Oil & Gas Pipelines spoke to Sheena Engledow, sales director of Pigs Unlimited International LLC, about the different types of cleaning pigs, their application in the field and best practices. Engledow has been with the company since 2013 and has served in a variety of roles within the company, including technical support, production and administration, in addition to inside and outside sales.
“I enjoy helping our customers find a solution to any challenges they may face on the job,” she says. “Pigs Unlimited was a very natural fit for me, and I look forward to our future as a company.”
Pigs Unlimited was founded in 1995 and provides an all-inclusive line of pigging products, manufacturing all styles of pigs, including foam, steel and solid-cast, as well as spare components, such as cups, discs and brushes. Since its inception, the company has manufactured all of its pigging products in the United States from its headquarters in Tomball, Texas, about 30 miles northwest of Houston.
In addition to serving the oil and gas pipeline industry, cleaning pigs are also used in other sectors, such as municipalities, power plants, mining, refineries, chemical plants, pulp and paper mills, food and beverage, and the cosmetic and pharmaceutical industries. Pigs Unlimited provides pigs in standard sizes that range in diameters from 2 to 48 in., but larger sizes can be designed and manufactured, and they can be manufactured in varying lengths, diameters, styles and configurations to best suit the customer’s application, according to the company’s website.
The following is a transcript of our conversation with Engledow about cleaning pigs.
Why are cleaning pigs an essential part of pipeline integrity management?
Engledow: Cleaning pigs are essential in pipeline integrity, because they are just that, cleaning pigs. For example, in order for a crude oil pipeline to perform to its maximum capacity, there need to be no obstacles in the line. If your line gets too much wax build up, you require more pressure to yield the same output, which makes everything have to work harder. Over time the pipeline will become filled with wax and it will be more expensive and much harder to clean at that time, than had there been maintenance cleaning program in place. Another example is cleaning pigs help in corrosion control by spreading inhibitors, removing scale and water. Pigs are also used to batch products for better use of pipeline capacity. To summarize, pigs have lots of valuable and essential uses
How often should cleaning pigs be deployed?
Engledow: This varies by type of line, type of product and type of service. Some lines must be pigged several times per day, while others may only need cleaning once a year, it really depends on the application and what the pipelines purpose and operation entails.
What are the different types of cleaning pigs, and how are they used?
Engledow: Considering the very first style of cleaning pigs were wadded up rags, the types of pigs have greatly evolved. Our main focus is foam, solid cast urethane and steel mandrel pigs. All can be equipped with different accessories such as magnets and brushes to meet the needs of our customers.
How do you work with companies to determine which pig is the best fit for the job?
Engledow: We ask a series of questions to understand what is going on inside of the line and what the goal of our customers is. At that time, we will make a suggestion to meet the needs of our customers. We are always amazed with the different applications, from cleaning barnacles out of a pipeline to cleaning a dual diameter line that has not been pigged in since the 1950s.
What advice would you give to customers to ensure the best results with using cleaning pigs?
Engledow: I would suggest my customers have a clear idea of their application and end goal. They should be aware of any obstacles that could potentially affect the outcome of the pigging job, such as bends, valves, pressure and volume.
What is the biggest concern among pipeline owners when it comes to the use of cleaning pigs?
Engledow: One of the biggest concerns of pipeline owner is downtime. Selecting the right pig for the job would decrease the chances of a loss in production, which ultimately affects everyone involved. Pig performance is also important.
How do you ensure that a cleaning pig is in the best condition to successfully complete a pigging run?
Engledow: First and foremost, make sure you are running a pig from a reputable manufacturer, such as Pigs Unlimited International. The pig should create a sufficient seal that allows appropriate scrapping of the pipe walls. Use fresh stock, do not use pigs with urethane components that have aged for years in storage.
What is the biggest misconception about cleaning pigs and how they work?
Engledow: The biggest misconception would be that one pig and one run is all that is needed to do the job, and any pig will do the job.
Where is the biggest opportunity for the pipeline industry in terms of improving integrity?
Engledow: Bottom line is just being proactive. Know your lines, know your challenges and have cleaning programs in place.
How do you view the pipeline industry in 2020? Is it on the upswing, declining or stagnate?
Engledow: The oil and gas industry is typically a little slower during election years. With both parties having completely different opinions about the oil and gas industry, these uncertainties negatively affect the market place. That being said, existing pipelines will still need to be cleaned and maintained.