[Date Prev][Date Next]
[cdn-nucl-l] " To pig or not to pig? "
To pig or not to pig? BP's oil pipeline question
By Deborah Zabarenko, Environment Correspondent
Fri Aug 11, 3:41 PM ET
WASHINGTON (Reuters) - Oil giant BP is learning some lessons from pigs in
its Alaska pipeline.
BP had not sent in the pigs at its Alaska line since 1992, relying instead
on ultrasound and other external techniques to inspect its lines, Chapman
said on Thursday in a telephone interview. The company does employ pigs
every five years in its North Sea pipelines, a company spokesman said.
PIGS IN THE PIPE
The 800-mile Trans Alaska Pipeline, which receives oil drilled by BP and
other North Slope producers, sends a scraper through its lines every week to
10 days and runs a smart pig every year to 18 months, said Dan Lawn, a
retired regulator at Alaska's Department of Environmental Conservation,
which monitors oil pipelines.
"To know where the pipe's thin, they have to run pigs," Lawn said by
telephone from his home in Valdez, Alaska. "If you just measure it with an
ultrasonic device from the outside, it will not give you verifiable data."
The government ordered BP to smart-pig its pipeline after a March spill of
200,000 gallons of crude onto the Arctic tundra. Back then, the line was so
clogged they had to send numerous scrapers through before a smart pig would
fit, said Damon Hill of the U.S. Transportation Department, which regulates
A smart pig run on July 22 showed pipe walls 80 percent corroded in spots,
with two places where there was 0.07 inch of steel -- about the thickness of
25 newspaper pages.
This surprised BP officials, who did not expect such corrosion from the type
of crude being carried -- a processed oil with water, sediments and gas
removed, Chapman said.
The smart pig found sludge in the pipe and microbiological activity despite
anti-corrosion chemicals, he said.
Lawn, a former engineer on the Trans Alaska Pipeline and now president of
the Alaska Forum for Environmental Responsibility, said BP was repeatedly
warned by workers and inspectors about possible corrosion.
No virus found in this outgoing message.
Checked by AVG Free Edition.
Version: 7.1.405 / Virus Database: 268.10.9/417 - Release Date: 8/11/2006