In case you missed it.
http://apnews.myway.com/article/20100508/D9FIL6L00.html
May 8, 8:04 AM (ET)
By JEFF DONN AND SETH BORENSTEIN
HOUSTON (AP) - Cutoff valves like the one that failed to
stop the Gulf of Mexico oil disaster have repeatedly broken
down at other wells in the years since federal regulators
weakened testing requirements, according to an Associated
Press investigation.
These steel monsters known as blowout preventers or BOPs -
sometimes as big as a double-decker bus and weighing up to
640,000 pounds - guard the mouth of wells. They act as the
last defense to choke off unintended releases, slamming a
gushing pipe with up to 1 million pounds of force.
snip
- Accident reports from the U.S. Minerals Management
Service, a branch of the Interior Department, show that the
devices have failed or otherwise played a role in at least
14 accidents, mostly since 2005.
- Government and industry reports have raised questions
about the reliability of blowout preventers for more than a
decade. A 2003 report by Transocean, the owner of the
destroyed rig, said: "Floating drilling rig downtime due to
poor BOP reliability is a common and very costly issue
confronting all offshore drilling contractors."
- Lawsuits have fingered these valves as a factor in
previous blowouts.
snip
After the accident, BP CEO Tony Hayward said of blowout
preventers in general: "It's unprecedented for it to fail."
Yet the AP review turned up instances where preventer seals
have failed outright, obstructions have blocked them, or
valves simply weren't designed for the task. Sometimes there
were blowouts.
The control systems also have proved goof-prone. When a
worker accidentally disconnected a blowout preventer at one
rig in 2000, federal regulators recommended changes in the
control panels. Later that year, a worker at a rig off the
Louisiana coast was making those very changes when he
accidentally pushed the wrong button - and unlatched the
valves; the ensuing blowout released 8,400 gallons of crude.
The government has long known of such problems, according to
a historical review conducted by the AP. In the late 1990s,
the industry appealed for fewer required pressure tests on
these valves. The federal minerals service did two studies,
each finding that failures were more common than the
industry said.
But the agency, known as MMS, then did its turnaround and
required tests half as often. It estimated that the rule
would yield an annual savings of up to $340,000 per rig. An
industry executive praised the "flexibility" of regulators,
long plagued with accusations that it has been too cozy with
the industry it supervises.
Laurence Power, of Robert Gordon University in Aberdeen,
Scotland, an engineering teacher who has studied these
valves in offshore oil wells, said he has "not been able to
see their logic" for reducing the frequency of testing.
In 1999, right after that rule change, an MMS-commissioned
report by a research group identified 117 blowout preventer
failures at deepwater rigs within the previous year. These
breakdowns created 3,638 hours of lost time - a 4 percent
chunk of drilling time.
In 2004, an engineering study for federal regulators said
only 3 of 14 new devices could shear pipe, as sometimes
required to check leaks, at maximum rated depths. Only half
of operators accepting a newly built device tested this
function during commissioning or acceptance, according to
the report.
snip
Two years later, a trade journal's article still noted that
shearing preventers "may also have difficulty cutting
today's high-strength, high toughness drill pipe" at deep
wells.
The special cutting preventers were blamed in 1979 for the
biggest peacetime well spill in history, when about 140
million gallons of oil poured from a Mexican well in the
Gulf.
Questions about reliability hung heavily but were mostly
unspoken Thursday at a Houston conference on offshore oil
rig technology. Shown a spreadsheet of problems with blowout
preventers, Transocean technology manager John Kozicz said,
"We know that - but they don't happen frequently."
Even Transocean's Earl Shanks, lead author of the 2003 study
reporting "poor BOP reliability," now views blowout
preventers as "very reliable." But he did acknowledge
problems in the complex electronic and hydraulic tangle that
activates and controls the devices. At Deepwater Horizon, he
said, "Something went wrong - and we don't know what."
snip
Cameron International, which made the Deepwater Horizon
preventers, has acknowledged that these lumbering emergency
stoppers need lots of upkeep. "You have to maintain it," CEO
Jack Moore told investors last year. "You have to replace
the mechanical and rubber elements."
snip
--
-- Unka George (George McDuffee)
...............................
The past is a foreign country;
they do things differently there.
L. P. Hartley (1895-1972), British author.
The Go-Between, Prologue (1953).