This illustration shows how spectral imagery, right, can detect problems traditional photography can’t see.

Move over Method-21, OGI cameras poised to improve LDAR

Aug. 31, 2018
New optical gas imaging (OGI) technology is more practical than old Method-21 “sniffing” for Leak Detection and Repair (LDAR)

LOOK more frequently – look faster.

With new optical gas imaging (OGI) technology, in lieu of the Environmental Protection Agency’s old Method-21 “sniffing” for Leak Detection and Repair (LDAR), that approach not only is practical, it’s preferred, said Brandon Mogan, president of Tora Consulting, which provides environmental and engineering business advisory services.

Mogan delivered his message to terminal owners and operators during the “Approaches to Detecting Leaks and Measuring Fugitive Emissions” session at the International Liquid Terminal Association’s 38th Annual International Operating Conference & Trade Show in June in Houston, Texas.

“We feel optical gas imaging is the way to go for LDAR for a lot of reasons,” Mogan said. “It’s far more efficient than the old Method-21 approach, and so from an emissions perspective, from a cost perspective and a product-loss perspective – all around – it’s a much better technology.”

The session also included input from Terence Trefiak, founder and president of Tora’s sister company, Target Emission Services – Target’s their field services arm, Tora’s the consulting arm – and Peter Weaver, whose new startup, Orbital Sidekick, looks for leaks from air and space.

Seeing clearly

When the first LDAR regulations for reducing Volatile Organic Compound (VOC) emissions from leaking piping and equipment components promulgated in the 1980s, Method-21 detection, using a portable instrument to detect VOC leaks from individual sources, was the only accepted method.

The EPA began modifying its New Source Performance Standards in the early 2000s, adding connectors to the list of components that must be monitored and reducing the leak definition from 10,000 parts per million by volume (ppmv) to 500 ppmv for most components, and finally adding cameras as an approved Alternative Work Practice (AWP) in 2008.

But some states, including California and Texas, still mandate Method-21 as the primary method of monitoring.

The reasoning behind that requirement is faulty, Mogan said.

According to Tora’s data, Method-21 sniffing of 99 percent of the 120,000 monitored components detected nothing, with most of the detected emissions escaping from a tiny fraction of counted parts.

“Ninety-three percent of the emissions come from .32 percent of the components, which is staggering,” Mogan said.

“So when you’re doing a typical Method-21 monitoring survey you’re spending 99% of your time looking at nothing, when these huge leaks are out there waiting to be found, and that is the reason we’re so passionate about OGI technology.”

Regulators who aren’t as passionate as Mogan will say OGI cameras are not equivalent to Method-21 instruments because Method-21 sniffing detects the tiniest of leaks, down to nearly zero ppmv.

That’s much lower than the camera can see – but, Mogan says, who cares?

“Yea, the camera’s not going to see that, but when we’re looking at the data set … that’s not where the emissions are coming from,” he said.

The first time Trefiak, who became familiar with Method-21 while working for Conoco Phillips, saw the prototypes for FLIR’s gas-finding cameras in 2005 at a technology conference, he said he knew “it was going to change the industry,” but adoption’s been slower than he imagined.

Change coming

Some state regulators are resistant to change, and so are some of the vendors who supply Method-21 testing.

But change is coming – and the sooner the better, he said.

Method-21’s an older industry, so it’s commoditized, but profit margins are low, so less reputable vendors have lower hiring standards and, consequently, lower work-quality standards, contributing to fraudulent activity, including technicians in trucks pushing buttons instead of monitoring equipment.

And, according to one EPA study, even if they’re out there physically monitoring the equipment, a 1-centimeter variance in probe positioning increases the chance of missing a leak – by up to 57%.

That’s problematic because the task of probing thousands of components already is monotonous, leading to complacency and lack of focus, and technicians are limited to testing what they can reach.

With OGI, instead of using point-source detection, techs can scan multiple components, including previously inaccessible and unregulated equipment, all at one time, with a camera that “sees” leaks.

“Not only can you do it much faster, you can see exactly where the leak is, and know it’s coming out of this side of the connector or this valve packing, so it’s more effective and more efficient,” Trefiak said.

“So there’s a big difference in the amount of work you can do and the ability to find those leaks much faster.”

Ignore the zeroes

OGI technology also can reduce the number of misidentified “ghost” leaks, saving companies time and money.

“If you have a bunch of components condensed in one area and you’re trying to find a leak with a probe, you might think this valve is leaking when it’s actually a connector blowing gas on the valve,” Trefiak said.

“So you tag something that’s the wrong component and send someone out to fix it, and they’re fixing the wrong component … and the leaky one’s still leaking because it wasn’t properly detected.”

And with time-intensive Method-21, companies don’t have time to waste.

According to information published by the EPA, a Method-21 survey scans about 60 components per hour, so scanning 117,000 components would take 2,000 man hours, with roughly 1,980 of those hours spent looking at nothing, and 20 hours actually finding non-zero leaks.

OGI cameras scan 2,000 components per hour – and all 117,000 in roughly 60 hours.

“Forget about the zeroes,” Mogan said. “The argument that the camera is not equivalent to Method-21, because it can’t detect really small leaks, is irrelevant, because that’s not where the emissions are coming from. Who cares? So let’s ignore the zeroes and focus on finding the big leaks quickly.

“We want to look more often … and when we look, look faster.”

Space-based detection

Weaver’s company wants to look from higher up.

Orbital Sidekick, which was scheduled to launch its first imager into space June 28 on a SpaceX rocket, specializes in spectral intelligence, or using aerial and space-based hyperspectral imaging and analysis.

This type of remote-sensing imagery – the “macro” detection to OGI’s “micro” detection – reveals reflected electromagnetic radiation at much narrower wavelengths, or bands, than photographic imagery, allowing for differentiation on a chemical basis, instead of a purely optical basis.

“That allows us to differentiate, based on chemical properties, these unique spectral signatures that let you see much more than the eye can,” Weaver said. “And depending on what it is you are trying to seek out, which properties you’re trying to seek out on the ground, you can change the color bands, which are based on which wavelengths you’re focused on for the anomalies in question.”

With spectral imaging, it’s possible to differentiate fresh water from a bioremediation pond, or wetlands from marsh lands, and tease out specific hydrocarbons far more effectively than traditional methods.

That’s why Weaver’s confident pipeline operators want – and need – what he’s selling.

Improved protection

He pointed to a very convincing case for the technology Orbital Sidekick stumbled upon during a test of the technology, which revealed a leaky pipeline through the spectral reflectance of distressed soil.

All conventional forms of leak detection hadn’t shown any problems, Weaver said.

“This is a facility that was visited regularly by the operators, pretty much on a daily basis, and they had no indication that there was a leak present,” he said. “In fact, this was picked up on a 150-mile pipeline overflight we conducted as a test for an early client.

“We told them of this anomaly, and they went in and ended up excavating, and what they found, on an 8-inch pipe, was a hole in a natural gas pipe about the size of a dime … which they’ve since remedied.”

Weaver said Orbital Sidekick plans to launch its own satellite in late 2019, and have a “constellation” of satellites by 2021 capturing spectral imagery of companies’ assets every three days.

“A continually orbiting satellite is going to capture geolocated spectral images,” Weaver said. “These can be mosaiced together for an image of your facility … and running the algorithms for detecting anomalies, if a free hydrocarbon is visible, or frankly if any soil disturbances are there that also could represent something such as a hydrocarbon leak, we can detect it and flag it straight away.”