Tuesday, May 04, 2010

Updates on the Gulf Oil Spill

Oil Slick in the Gulf of Mexico on May 1, as seen by NASA's Terra ASTER

First, BP has built one of three coffer dams that it will try to use to collect leaking oil underwater.
BP Chief Operating Officer Doug Suttles said that the company had fashioned the first of three domes designed to be placed Tuesday "over the leak sources and allow us to collect the oil, funnel it up through pipework to a drill ship called Enterprise on the surface."

He added that the company expects "to load out the fabricated containment chamber tomorrow and we hope to have the system up and operating within a week." ...

Suttles admitted there would be "technical challenges" in trying to sink a 65-tonne structure down so deep, but said that despite the extreme pressure physics was to some extent in their favor.

"What allows this to work is the fact that oil is less dense than water and wants to float.

"Essentially an oil column exerts less pressure than a water column so that helps push the oil to the surface and we can assist that with other means."
This method was used to reduce the environmental damage from spills after Hurricane Katrina, but in much shallower water. Since this has not been tried with such a deep well, it is not known whether it will work. The link does not make clear what the timetable for the second and third containment chambers will be. A more permanent solution is to drill a relief well, but this is months away and similarly uncertain.
The Australian accident, known as the Montara spill, began Aug. 21 with a blowout of high-pressure oil similar to the one in the gulf. With the well spewing 17,000 to 85,000 gallons per day, precious weeks passed before the relief wells were started. When efforts got under way, the first four attempts — drilled on Oct. 6, 13, 17 and 24 — missed the original well.

A fifth attempt finally intersected the original on Nov. 1, and about 3,400 barrels of heavy mud were pumped through the relief well into the base of the original well. The spewing oil finally stopped Nov. 3 — more than 10 weeks after the original explosion.

BP intends to drill a similar relief well close to the site where the Deepwater Horizon drilling rig blew up and sank in the gulf nearly two weeks ago. The company says the well could take months to complete. In the meantime, the well continues to leak 210,000 gallons of oil a day, according to the latest official estimates.
BP's well in the Gulf of Mexico is at a much greater depth, which makes the plugging operation more difficult, but the seabed around BP's well is better mapped than the Montara well. In both operations, the goal is to hit a narrow shaft over a mile below the ocean floor. One additional connection between the two spills is that Halliburton did contract cement work shortly before each blowout.

Prior to Obama's announcement of expanded offshore drilling, NOAA warned that the Interior Department underestimated the risks of oil spills in its draft proposal.
NOAA complained that the draft report overstated the safety of offshore oil production by using information on frequency of spills from 1973 to 2004. NOAA pointed out there was a "substantial increase in spill volume in 2005, primarily due to spills associated with Hurricanes Katrina and Rita. Some of the damaged rigs and pipelines damaged during the 2004 and 2005 hurricane seasons continue to have episodic releases, and repairs have not been fully completed."

Citing Interior's own data, NOAA scolded it for asserting that it had "been many years since any substantial environmental impacts have been observed as a result of an oil spill caused by the [Outer Continental Shelf] production and transportation activities."

NOAA also wrote that the administration's "analysis of the risk and impacts of accidental spills and chronic impacts are understated and generally not supported or referenced, using vague terms and phrases such as 'no substantive degradation is expected' and 'some marine mammals could be harmed.'"
So far relatively few oiled birds have been recovered, and the first is already cleaned and recuperating. In that case, the oiled gannet happened to swim up to a boat. It is possible that other seabirds are getting oiled and not making contact with people before dying since the slick is large and has mostly stayed away from land. When parts of the slick are burned, the smoke presents a potential threat to migratory songbirds flying over the gulf; songbirds that die from smoke inhalation over the Gulf might not be found.

Birds are not the only animals at risk. Since the Deepwater Horizon explosion, dozens of sea turtles have been washing up dead on Mississippi beaches. Necropsies will be necessary to determine whether their deaths are connected with the spill.

Finally, Paul Krugman writes that the oil spill in the Gulf could rejuvenate the environmental movement.
For one thing, as visible pollution has diminished, so has public concern over environmental issues. According to a recent Gallup survey, “Americans are now less worried about a series of environmental problems than at any time in the past 20 years.”

This decline in concern would be fine if visible pollution were all that mattered — but it isn’t, of course. In particular, greenhouse gases pose a greater threat than smog or burning rivers ever did. But it’s hard to get the public focused on a form of pollution that’s invisible, and whose effects unfold over decades rather than days. ...

Then came the gulf disaster. Suddenly, environmental destruction was photogenic again. ...

For the gulf blowout is a pointed reminder that the environment won’t take care of itself, that unless carefully watched and regulated, modern technology and industry can all too easily inflict horrific damage on the planet.
This oil spill has gotten a lot of coverage, and the risks of offshore drilling have become more obvious. However, since the bulk of the spill has remained offshore, most of the environmental damage is also offshore, underwater, and out of sight. This allows oil industry supporters to liken the spill to chocolate milk or assert that the damage is minimal. By contrast, the Santa Barbara spill that Krugman references coated California beaches in heavy oil where the damage was visible and obvious. Even if Krugman is right, this disaster seems a heavy price to pay for bringing environmental problems back into the public consciousness.