Mewbourne Oil engineer invents device to increase underground pipeline safety
Andy Brosig/News-Sun
Erin McMath wasn’t satisfied with the way oil and gas companies were checking the safety of the miles of high-density polyethelene pipe they were burying in the ground of southeast New Mexico.
McMath is a native New Mexican, born in Albuquerque and raised in Los Alamos. He has two older brothers, one still living in Los Alamos near their father and another in Lamy.
McMath moved to Hobbs right after college in 2014 with his wife, Miranda, to take the job at Mewbourne Oil Co.
One of his duties as a production engineer for Mewbourne Oil Co. in Hobbs was ensuring the thick-walled “polypipeline,” as it’s known in the industry, was strong enough to hold up under the pressure of a variety of fluids it transports. A flaw or failure, he said, would result in a spill that could potentially endanger the environment, wildlife — or the people who lived near the pipelines.
A mechanical engineer by education at New Mexico State University, McMath grappled with his concerns until, one day about five years ago, he got an idea for a better way to test pipes before they were set in place underground.
“This all came about from installing polypipeline,” McMath told the News-Sun. “It wasn’t really something we were looking for. It’s just an idea I had.”
Polypipeline is manufactured using an extrusion process — essentially forcing molten material through a die to form the pipe.
Sometimes, though, the amount of material moving through the die would decrease. The outside diameter of the pipe would appear correct but, somewhere in the 50-foot lengths the company received from its suppliers, there would be a flaw. The walls of the pipe would just be too thin.
The only way to test the pipe was after it was put together into length stretching a mile or more and buried underground would be to force an electronic sensor called a smart pig through the pipe and download its data at the other end. Then crews would have to dig up the pipe where a flaw was located and replace it, hoping they’d found the correct section. But that process, too, wasn’t ideal, McMath said.
“It was very cumbersome and I didn’t feel like it was reliable,” he said. “They’d get stuck in there … and I didn’t know if the measurements were reliable.”
This is where McMath’s invention, which earned him a patent earlier this month, comes in.
His spider pig is a fully mechanical device for checking pipes as they’re unloaded at a work site.
In use, the a set of spring-loaded pins are pointed forward and held in place by the walls, then pulled manually through a section of pipe. If the pins have returned to the resting position when it emerges from the other end, that means it encountered a wider area somewhere along the way and the entire 50-foot section will be rejected.
“With this, I can measure each (section) of pipe as it comes off the truck,” McMath said. “That tells me if I have an issue at that point, we kick those (sections) out and they never get put in the ground.”
McMath approached the management of Mewbourne Oil Co. and received the go-ahead to proceed with his idea. He used his experience and training in computer-aided design to build the first spider pig and then tested it by the simplest method possible.
McMath took a shorter section of pipe to a machine shop and asked them to mill parts of the interior of the pipe to mimic the flaw. And his work was verified in that early testing when the pins on the spider pig was “sprung” when it emerged, he said.
And the first time the spider pig was put to work in the field, it identified a single pipe in the batch with the flaw.
The company now has about a half-dozen spider pigs in operation at pipeline sites around the region. And, by changing out the pins, the spider pig can measure and check virtually any diameter of pipe, McMath said.
“I’d figured out a way to measure the inside of a pipe that was simple and effective. One of the most rewarding things to me is we’re still using it” about five years after those first successful tests, McMath said. “The Mewbourne management has enough faith in it to keep using it.”
But that’s the way the company operates, he said. Company officials believe in their engineers being hands-on in the field rather than sequestered in corporate offices in big cities, sometimes hundreds of miles away from production areas, just reading reports from the people actually doing the work.
“The mentality and culture of Mewbourne of putting your hands on stuff, learning it first-hand,” he said. “When you see it first hand, when you’re there in person, I think you get a much better idea of what’s going on.
“(These pipelines) are running through farm fields, near waterways, past people’s houses. I have to feel good about the pipe we’re putting in the ground or you’re affecting real people’s lives. We’re trying to protect the people, the water, the environment, animals — everything.
