Posted on 08/10/2006 6:56:42 AM PDT by thackney
Small spots may be caused by bacteria hidden in pipe's sludge
The pipeline that sprang a leak over the weekend, triggering a convulsive shutdown of the huge Prudhoe Bay oil field, is pocked with at least five holes possibly caused by a virulent strain of corrosion, according to state and industry sources.
Oil managed to escape from one of the holes, creating a pool of up to 210 gallons on the summer-green tundra before field workers spotted and stopped the leak early Sunday.
The other holes were discovered after workers for BP, the British oil giant that runs Prudhoe, stripped off insulation and a metal jacket that wrap the above-ground pipe on the eastern side of the oil field. The wrappings blocked leaks from more of the holes.
Repairs crews have temporarily patched all the holes, each smaller than a peanut, state officials said.
There are good odds the pipeline has further breaches. BP managers said the pipe was tested in late July with a device called a smart pig, an electronic probe that slides through pipes looking for thin spots in the steel walls.
That report contained alarming results for BP -- indications of 16 anomalies, each a potential hole. BP crews were checking out these spots over the weekend when they noticed oil leaking onto the tundra, prompting top BP executives to order a complete shutdown of Prudhoe, the nation's largest oil field.
The action spooked the energy-strained country, bumping up crude prices and unleashing a torrent of accusations that BP had invited the shutdown by failing to properly clean and test the pipes.
(Excerpt) Read more at adn.com ...
Keith Holms of Powderly, Texas, works on a steel sleeve Wednesday in Deadhorse. The sleeve will be used to repair weak spots on BP's oil transit lines in Prudhoe Bay. BP Exploration (Alaska) Inc. began shutting down the oil field Sunday after the discovery of unexpectedly severe corrosion and a small spill from an oil transit line.
Oil pipelines have "pigs" running through them all the time. Basically a computer donut on wheels that travel throughout the inside of pipes with scanners on the outside that constantly check the pipe walls for holes, corrosion and problems with pipe thickness, etc.
What happened with those here?
Pigs may be run all the time, but smart pigs less often. But I am sure they will be run more often by many.
I've encountered MIC (microbiologically-induced corrosion) in copper conderser tubing taken from a nuclear power plant. In that case MIC produced pit-like features.
MIC can produce a defect with a very high aspect ratio (large depth divided by a very narrow area of attack). If the "pig" is looking for wall thinning, it will not see MIC. However most eddy current techniques (the assumed detection method) can readily detect the presence of MIC. The presence of a weld feature may mask detection.
Yes, sludge deposits can be places where MIC is protected. Sludge would tend to form near weld features as well.
I'm curious if these defects were located near welds. If not, BP has a detection and a cleanliness issue.
From their annoying bad-acting-liberal-enviro-compassionate supposedly forward thinking commercials it appeared that such and oversight could never be a possibility. ./gasp
4 barrels of oil is a "pool"???
This was a mop-and-bucket-cleanup type of leak. Looks like BP caught it early.
Leni
Oil leaks into the Tundra and tar bubbles up in the parking lot of La Brea tar pits in Los Angeles ( naturally ). Back in the old days people used to leave 210 gallons of motor oil on the ground after years of changing and dumping their own oil from automobiles .
They didn't run the "cleaning pigs" frequently enough, and the sludge built up to the point that it was considered potentially detrimental to the downstream pipeline to run the "cleaning pig" (would dump too much sediment load at once). With the sludge buildup, they could not run the "smart pig".
Hey--there's already ONE flying pig---moi!
Sadly, an oil spill today is different. Used to ba spill was a spill - nowdays, a leaking packing ring is considered an oil spill and forms have to be filed with the DOG.
Oinks up!!!!
Leni
Isn't there some type of antibiotic they can use against the bacteria? How did the bacteria get to AK in the first place?
I'm trying to learn but I know little about this bacteria. I understand it is not brand new in the industry but new at this point.
More information concerning the impact from the spill in March:
BP: Learning from oil spill lessons
http://www.petroleumnews.com/pntruncate/573947058.shtml
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