Smart pigs sniff out pipeline safety
Posted: 2 September 2003
NESCO proactive approach builds positive community relationships
At a time when developing energy resources often attracts more
negative than positive press, Kirkland, Washington-based National
Energy Systems Company (NESCO) is taking a decidedly quiet, proactive
approach to environmental protection and safety. And while State
Governor Gary Locke has praised their latest power plant proposal
(Sumas Energy 2) for setting what he calls "a new standard
of excellence for environmental protection," much of their
best work remains underground.
Now one of NESCO's affiliate companies, Sumas Cogeneration Company,
LP (Sumas 1) has implemented a new approach to safety and the environment
that so far has not caught the public's attention-partly because
it anticipates rather than responds to safety regulations, and possibly
because few people outside the industry have any idea what subsurface
"smart pigs" really do.
Pigs prove it
The pigs, of course, are highly sophisticated in-line inspection
tools, contracted by Sumas 1 at a cost of over a quarter-million
dollars to thoroughly inspect nearly 3.7 miles of eight-inch underground
gas supply pipeline connected to the partnership's 125-megawatt
natural gas-fired power plant. "Smart" pigs, supplied
by the Houston-based Tuboscope Pipeline Services, Inc., provided
an unprecedented inside-out close-up of the pipeline during an exhaustive
series of tests last June (2002). Even one of the world's experts
in smart pig technology, Marcelo Baldez of Pipeway Engenharia in
Brazil, was on hand to help oversee the tests, along with representatives
from the engineering firm of CH2M Hill and from the Washington State
Utilities and Transportation Commission (WUTC). Results of the in-line
inspection, or ILI, showed zero indications of wall cracks or corrosion
in the 10-year-old pipeline.
"This pipeline is in top condition," reported Ron Maurier,
Tuboscope's Director of Pipeline Assessments. "With no reportable
degradation after ten years, these guys have everything to be proud
of."
How could Maurier be so sure? Tuboscope's system, under development
since 1967, incorporates some of the industry's most sensitive electronics.
So sensitive, in fact, that they were able to detect four nearly
invisible surface variations in the 19,373-foot pipeline. The largest,
at .19" (2.3% of the pipe inside diameter), barely exceeded
reporting criteria (.17) and proved well within allowable CFR (Code
of Federal Regulation) tolerance (.250 for pipes of up to 12-inch
diameter). The remaining three remained below typical reporting
standards.
Even though the variations were within tolerances and typical reporting
standards, last November Sumas 1 technicians pinpointed the section
of pipe with the variation, uncovered it and added a failsafe patch.
Part safety, part example
Pipeline Safety Engineer Patti Johnson of the WUTC came to see the
testing, as well. She came away saying the company is "going
the extra mile, and showing they take pipeline safety seriously."
She also said that while "state law does not require Sumas
1 to do an internal inspection of the pipeline; they have done this
voluntarily. We commend the company for their actions."
Of course, Sumas 1 Senior VP Bruce Thompson knew the testing wasn't
legally required for their 8-inch natural gas line. But, he said,
"we are all aware that pipelines continue to be the safest
means of transporting natural gas, but we are also aware that within
the last four years, there have been a variety of local, regional,
and national pipeline accidents that have brought the issue of pipeline
safety to the public. For this and other reasons, we simply decided
to do this test now, rather than later."
Part safety, part example. "This way," he added, "maybe
other companies will take notice and join us to help protect the
environment and human health. Maybe they'll see that this test can
be effectively done on 8-inch lines or smaller gas delivery systems
belonging to investor-owned and public utilities."
Other NESCO officials agree this kind of proactive inspection and
upgrade may appear ambitious, particularly when it exceeds state
or federal mandates. But it seems just a matter of time before government
standards will catch up with NESCO's.
Since 1984, the Federal Office of Pipeline Safety has been in charge
of monitoring standards for pipeline operators, including the number
of pipeline failures, injuries or deaths, and monetary losses. Proposed
regulations will mandate two ways to inspect: pressure testing and
ILI. Of those, ILI is the preferred method, as it mitigates the
potential for damage to the pipeline and minimizes disruption to
daily operations-even as it provides a starting point, what Maurier
calls a "a baseline to manage the pipeline into the future."
That's where the "smart pig" comes in.
A miniature fire plug
Smart pigs, which actually resemble a miniature fire plug but are
packed with sophisticated instrumentation, are designed to snake
their way through some of the most convoluted bends in underground
pipelines. These instruments range from simple cleaning pigs to
high-tech bundles rivaling satellites in complexity. In fact, many
smart pigs are equipped with advanced, laser-based inertial navigation
systems (INS) similar to those found in Tomahawk cruise missiles.
What's more, the pig's ultra-precise gyros and accelerometers link
with GPS locators and triangulate with NGS charts for accuracy to
within centimeters. So the pigs used for Sumas 1 provided GPS coordinates
of all pipeline features, from welds and valves to bends in Whatcom
County. That gave them an accurate map along with an inch-by-inch
definition of the pipeline's unique characteristics. In addition,
the Geographic Information System (GIS) served up a complete profile
of the area surrounding the pipeline, even as it integrated pipeline
features with its maps.
Many runs, no problems
Tuboscope actually completed 11 pig runs at Sumas 1 between June
1 and 14. This included two purge pigs, three cleaning tool runs,
one gauging tool run, one electronic caliper, two dummy tool runs,
and two "live" Magnetic Flux Leakage (MFL) metal loss
runs.
MFL uses powerful magnets to induce a magnetic field in the pipeline,
while rows of sensors detect magnetic field leakage if there is
any metal loss inside or outside the pipe. Meanwhile, an odometer
measures and records distance data to pinpoint any problems. There
were none in Sumas.
Typically the pig would crawl at three or four m.p.h. through the
pipeline, gathering high-resolution deformation caliper data, which
was in turn integrated with high-resolution MFL corrosion data.
In other words, with information from the pig, plant engineers could
see and compare different realms of analysis at a glance.
The 3.67 mile pipeline is constructed primarily of Grade X-42,
ERW manufactured, .250 inch nominal wall pipe, with some portions
of .322 inch nominal wall pipe.
The integrity benchmark
According to Maurier, Sumas 1 will realize several immediate benefits
from the test. First, it's an "integrity benchmark," so
that future testing and daily operations will benefit from the work
completed in 2002. Sumas 1 can also establish a "Pipeline Integrity
Management" process for the future. And the test will help
them reinforce an effective preventive maintenance program, protect
the pipeline's integrity and ensure safe operation using some of
the most advanced technology available.
What's more, the pipeline is now set up for easy future "pigging."
Despite the absence of any internal corrosion this time, Sumas 1
has the option to pig the line once a year to keep it clean. Staff
members are now fully trained and equipped to run the system.
Good business, good neighbors
Yes, this kind of testing carries up-front costs. But is it good
business? Absolutely, said Thompson: "We invest in the machinery
to protect the environment, respect our neighbors and employees,
both for the short-term and the long-term."
In the process, NESCO and Sumas 1 went out of their way to respect
private property and to minimize any disturbances. And the effort
paid off from a public relations standpoint, as well.
"All our interactions with local residents were positive,"
said Maurier.
NESCO has followed this approach in Whatcom County since 1993,
when Sumas Cogeneration started commercial operation. Operated by
the Calpine Corporation, the 135 megawatt plant generates enough
power for about 80,000 homes, which Puget Sound Energy buys for
distribution throughout its regional transmission grid.
An environmental leader
But there's more than just power generation. Sumas 1's heat exhaust
generates the steam needed to dry lumber and wood products at the
adjacent SOCCO Forest Products facility. In the process, Sumas Cogeneration
set a new, more stringent standard for "Best Available Control
Technology" (BACT) when it was permitted in 1992. More recently
Jamie Randles, director of the Northwest Air Pollution Authority,
said "the plant is one of the cleanest fossil fuel fired energy
plants in the region."
Sumas Energy 2 (SE2) follows the same pattern of success. In fact,
EFSEC reported that SE2 will set a "new standard of excellence
for the protection of the environment and the public interest"
and that its greenhouse mitigation offer was unprecedented in the
state of Washington.
The facility will establish a new benchmark for Best Available
Control Technology in the Pacific Northwest and promises to be over
twice as clean as anything built to date or being proposed. In addition,
SE2 has agreed with the WUTC and the State Energy Facility Site
Evaluation Council (EFSEC) to smart pig the 16-inch underground
gas pipeline for SE2 after construction is complete.
"This company has a proven track record in our community,"
said Bob Bromley, Sumas mayor, "and will be a good corporate
neighbor for decades to come."
So whether it's pipeline testing or power plant design, this kind
of local acceptance continues to validate NESCO's philosophy and
approach.
"NESCO demonstrated that low mileage operators can achieve
industry leading pipeline integrity programs," said Maurier.
"I believe there are dozens of companies such as NESCO who
would be interested in the business aspect of what was achieved
and why it was done. Even for companies who are not primarily pipeline
operators, but who nonetheless own pipe, leading edge integrity
and regulatory compliance management is not only possible, it's
good business."
Posted by Richard Price,
Editor Pipeline Magazine
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