Key oil spill evidence raised to Gulf's surface
ON THE GULF OF MEXICO
It took 29 1/2 hours to lift the 50-foot, 300-ton blowout preventer
from a mile beneath the sea to the surface. The five-story high
device breached the water's surface at 6:54 p.m. CDT, and looked
largely intact with black stains on the yellow metal.
FBI agents were among the 137 people aboard the Helix Q4000
vessel, taking photos and video of the device. They will escort it
back to a NASA facility in Louisiana for analysis.
The AP was the only news outlet with a print reporter and
photographer on board the ship.
Crews had been delayed after icelike crystals -- called hydrates
-- formed on the blowout preventer. The device couldn't be safely
hoisted from the water until the hydrates melted because the
hydrates are combustible, said Darin Hilton, the captain of the
Helix Q4000.
Hydrates form when gases such as methane mix with water under
high pressure and cold temperatures. The crystals caused BP PLC
problems in May, when hydrates formed on a 100-ton, four-story dome
the company tried to place over the leak to contain it.
As a large hatch opened up on the Helix to allow the blowout
preventer to pass through, several hundred feet of light sheen
could be seen near the boat, though crews weren't exactly sure what
it was.
The April 20 explosion aboard the Deepwater Horizon killed 11
workers and led to 206 million gallons of oil spewing from BP PLC's
undersea well.
Investigators know the explosion was triggered by a bubble of
methane gas that escaped from the well and shot up the drill
column, expanding quickly as it burst through several seals and
barriers before igniting.
But they don't know exactly how or why the gas escaped. And they
don't know why the blowout preventer didn't seal the well pipe at
the sea bottom after the eruption, as it was supposed to. While the
device didn't close -- or may have closed partially -- investigative
hearings have produced no clear picture of why it didn't plug the
well.
Documents emerged showing that a part of the device had a
hydraulic leak, which would have reduced its effectiveness, and
that a passive "deadman" trigger had a low, perhaps even dead,
battery.
Steve Newman, president of rig owner Transocean, told lawmakers
following the disaster that there was no evidence the device itself
failed and suggested debris might have been forced into it by the
surging gas.
There has also been testimony that the blowout preventer didn't
undergo a rigorous recertification process in 2005 as required by
federal regulators.
Recertifying the five-story device requires completely
disassembling it out of the water and can take as long as three
months to complete.
Testimony from BP and Transocean officials also showed that
repairs were not always authorized by the manufacturer, Cameron
International, and that confusion about the equipment delayed
attempts to close the well in the days after the explosion.
A Transocean official has said he knew the blowout preventer was
functioning because he personally oversaw its maintenance, and he
said the device underwent tests to ensure it was working. The
device, he said, had undergone a maintenance overhaul in February
as it was being moved to the Deepwater Horizon to be placed over
BP's well.
Also, according to testimony, a BP well site leader performed a
pressure test April 9 on the blowout preventer, and he said it
passed.
George Hirasaki, a Rice University engineering professor, said
the blowout preventer should have sheared through the drill pipe
and shut off the flow of oil. There may have been two sections of
drill pipe or a thicker section, called the "collar," that the
blowout preventer could not shear through, he said.
He also said the device's hardware was changed, but the on-site
drawings were not updated to reflect the changes. Investigators
will be looking for any other discrepancies between the device and
its drawings.
In short, Hirasaki said, "The BOP failed to do its function. It
is important to determine why so that it does not occur again."
However, some have cautioned that the blowout preventer will not
provide clues to what caused the gas bubble. And it is possible a
thorough review may not be able to show why it didn't work.
That could leave investigators to speculate on causes using
data, records and testimony.
Lawyers will be watching closely, too, as hundreds of lawsuits
have been filed over the oil spill. Future liabilities faced by a
number of corporations could be riding on what the analysis of the
blowout preventer shows.
A temporary cap that stopped oil from gushing into the Gulf in
mid-July was removed Thursday. No more oil was expected to leak
into the sea, but crews were standing by with collection vessels
just in case.
The government said a new blowout preventer was placed on the
blown-out well late Friday. Officials wanted to replace the failed
blowout preventer first to deal with any pressure that is caused
when a relief well BP has been drilling intersects the blown-out
well.
Once that intersection occurs sometime after Labor Day, BP is
expected to use mud and cement to plug the blown-out well for good
from the bottom.