Look for Leaks: Infrared uncovers fugitive gases hidden to the naked eye
Written by Andre Voshart
Over
the past few decades, infrared cameras have revolutionized maintenance
in many industries by finding hidden electrical and mechanical faults
before major equipment damage can occur, saving money and enhancing
worker safety.
Infrared also plays a role in helping to decrease environmental damage
as certain cameras, such as those manufactured by FLIR, can detect
environmentally dangerous gas leaks, also known as “fugitive
emissions.” In Alberta and British Columbia, energy regulators have
also issued a directive that contains requirements for upstream
facilities to have a fugitive emission management plan.
Fugitive emissions commonly escape from pipelines, gas plants, storage
tanks and refineries, usually at connection points, and are most
commonly methane, ethane and propane. The source of these emissions can
either be intentional (such as from venting from tanks, controllers,
stacks, etc.) or unintentional (such as from equipment wear and tear,
incomplete assembly of components, defects, etc.). These emissions can
cost the industry millions of dollars in lost product, pose safety
risks to workers and the public and account for a significant amount of
the total inventory of greenhouse gases emitted by the oil and gas
industry, according to a study by Calgary-based Target Emission
Services, which provides emission detection services.
Earlier methods of gas detection required close contact using “sniffer”
technology and probes, and while accurate, they run a risk of missing
leaks and could expose inspectors to invisible and potentially harmful
chemicals. As well, wind and weather factors can produce inaccurate
measurements. Infrared gas detection cameras, on the flip side, are
able to visualize the gas by producing real-time, recordable images and
video of the scanned area, with leaks appearing as billows or wisps of
“smoke.”
The applications are almost limitless.
Improved efficiency
According to FLIR, up to 84 percent of leaks occur in less than one
percent of the plant, so most of the time, conventional leak-finding
tools are scanning leak-free components. Additionally, systems don’t
have to be shut down during the inspection and measurements can be
carried out remotely; and since a gas detection camera works without
making contact, it can be used in hard-to-access locations and can
detect small leaks from several metres away and big leaks from hundreds
of metres away.
Back in 2006, ConocoPhillips Canada did a pilot study to check the
technology’s effectiveness, and during the study, 22 facilities from
various asset areas were assessed for fugitive emissions. In the end,
they discovered 144 leaks, according to the report on the project by
Target Emission Services’ Terence Trefiak, the first person in Canada
to use FLIR’s GasFindIR technology in upstream oil and gas facilities.
The technology, he says, has undergone major developments since 2006.
“In 2009, the HSX model was released. This version of the camera has
about eight to 10 times more sensitively than the original model. … In
2010, FLIR released its second-generation version of the camera [with]
many advances that make the camera more user friendly.”
Since the pilot study, he has done countless assessments, and the
results aren’t always what clients expect. “The majority of times, we
find more leaks at facilities than are expected,” he says. “Usually the
size of the leak or the location of the leak is surprising to our
clients. When you show a facility operator an infrared video of a leak
for the first time, their eyes usually get bigger and their jaws drop a
little.”
For the pilot project, the repair costs were determined and a
cost-benefit analysis was performed. It was estimated that 92 per cent
of the leaks were economical to repair and would save the company
$358,000 per year.
“Having the ability to visually show them something that is invisible
to the naked eye really has an impact and generally gets them more
invested in the program,” Trefiak says. “When we provide corporate
summaries of multiple facility assessments, the numbers sometimes
surprise our clients. On average, the value of gas leaks we detect is
many times larger than the cost of the assessment.”
Regulating leaks
Fugitive gas emissions contribute to global warming, and the GasFindIR
detects dozens of volatile organic compounds (see Page 12), including
the “greenhouse gas” sulfur hexafluoride.
In Canada, as of the beginning of 2010, companies in Alberta must abide
by the Energy Resources Conservation Board’s (ERCB) Directive 060:
Upstream Petroleum Industry Flaring, Incinerating, and Venting, and the
ERCB will be ensuring compliance with the requirements. Basically,
operators must develop and implement a program to detect and repair
leaks and the program must meet or exceed the CAPP Best Management
Practice for Fugitive Emissions Management guidelines. Surveys are
scheduled roughly once a year, depending on the leak type. To review
the requirements, download the document at www.capp.org.
Preston Smith is an air monitoring technologist as well as the health,
safety and environment coordinator with Diagnostic Engineering in
Calgary. He says it is understood that certain components are more
likely to see leaks due to their operation, usage, pressure handling
and containment than others, so there two situation that can come from
having a leak: fix it or leave it.
If the costs to repair the leak (replacement, shutdown and gas costs)
is less than the annual cost of the leak, he says it would be fixed and
“would then be resurveyed on the next survey based on the schedule as
set by the CAPP documentation. If the subsequent surveys were to show
that the leak was no longer, that company could apply for a survey
schedule extension as they have a record of good componentry behaviors.”
However, if the costs to repair is greater than the cost of the leak,
“it would be hard to justify the repair,” Smith says. “It would remain
leaking and could be considered for survey on a more frequent basis. If
it is a component that is a high-risk leak volume, it would likely be
checked on a shorter time scale than the schedule.”
Regardless of the cost, the CAPP document states that any leak that is
a safety hazard must be fixed immediately regardless of economic or
volume of loss, he says.
“Currently, it is the responsibility of the companies to track and
manage their facility leaks and arrange repairs and reschedule surveys.”
To help Canadian operators stay in compliance, companies like
Diagnostic Engineering and Target Emission Services provide gas
imaging, management-program development and leak rate measurement.
Trefiak, with Target Emission, produces a customized fugitive emission
management program (FEMP) to meet or exceed regulatory requirements,
designed to be cost effective.
“Providing a good communication and tracking system is important,” he
adds, “but you still need to have your facility operators and
maintenance staff engaged in the program to make a difference.
Corporate leadership has the biggest impact in most companies.”
Applications
The mid-wave gas detection camera is suited to several industries,
including oil refining, petrochemical, chemical, power generation and
natural gas. Infrared responds to most of the “light end” products and
intermediates found in fuels processing refineries, and most of the
chemicals used or made in the petrochemical industry have good
visibility. Natural gas consists mainly of methane and ethane, both of
which are clearly detectable with the mid wave camera, and can be
detected from the gas production field right through the distribution
network to the end consumer.
The camera can be used to detect gas from many different sources in the
petrochemical industry, but some of the most common leak paths are from
flanges, valve stems, plugs, caps, machinery, couplings, pump seals,
holes, passing valves, drain covers and instrument connections.
The camera has had proven success in leak detection surveys during the
start up of process plants following both planned and unplanned
shutdowns. The thermal cycles associated with shutdown and startup can
initiate leaks in equipment that was previously leak free and
components that have been disturbed due to maintenance activity may
also leak.
While Alberta and B.C. have taken the largest steps to regulate
fugitive emissions, other federal, provincial and municipal agencies
have their own codes regulating airborne contaminants — both enforced
and recommended — but Trefiak says more prescriptive legislation may be
coming down the pipes.
“In the U.S., the new Mandatory Reporting of Greenhouse Gases Rule has
a very prescriptive regulation (Subpart W) that requires very specific
fugitive emission monitoring at U.S. oil and gas facilities,” he says.
“This rule is extremely detailed and requires that each facility that
emits over 25,000 tonnes of CO2 must monitor its fugitive emissions
annually. I would suspect that the Canadian governments will eventually
mirror this reporting rule to stay at par with the international
community.”
André Voshart is the editor of REM. The report includes research done by FLIR and Target Emission Services.
Over
the past few decades, infrared cameras have revolutionized maintenance
in many industries by finding hidden electrical and mechanical faults
before major equipment damage can occur, saving money and enhancing
worker safety.
