Peak Oil

BP Oil Spill Worst-Case Scenario

By Ryan McGreal
Published June 17, 2010

The BP Deepwater Horizon oil spill is already an appalling environmental disaster. It may turn out to be America's Aral Sea. But what if it's about to get a lot worse?

The rig Deepwater Horizon started drilling the Macondo well in February 2010. They drilled a 5.5 kilometre shaft from the sea floor (which was itself 1.5 kilometres below surface) and encased the shaft in cement. BP had advised the US government that the risk of a spill was unlikely, but internally, its engineers warned of serious problems with pressurized natural gas in the well.

On April 24, a high-pressure gas release ignited on the rig, causing an explosion and fire. The rig burned for 36 hours and then sank. Eleven of the rig workers were not rescued or found and are presumed dead.

BP had fitted the wellhead with a blowout preventer that was supposed to seal the well automatically if it lost contact with the rig, but on April 22, the Coast Guard noticed oil leaking from the rig site. BP dispatched remote vehicles to the wellhead, but they were not able to plug the leak either.

Since then, the wellhead has been gushing between 30,000 and 60,000 barrels a day (one barrel is 117 litres) into the Gulf. After nearly two months of flow, the oil spill covers an area of 6,500 square kilometres. BP is catching a fraction of the oil as it leaks into the ocean, and they are flaring some of the methane gas

BP has attempted to seal the wellhead using a top kill, which is a temporary injection of drilling mud into the blowout preventer to plug it until they can install a more permanent cap.

However, their attempts have failed so far, and observers have noted that while top kills are a standard way to plug wells on the surface of the earth, the method has never been attempted at 1.5 kilometres below sea level.

The longer-term strategy is to drill two relief wells to divert the flow of oil away from the main wellhead and capture the oil before it is released into the Gulf. Once the pressure comes off the main wellhead, it should be easier to plug.

However, a recent comment on The Oil Drum that is generating a lot of interest on the internet right now presents a coherent, well-sourced claim for a worst-case scenario. The comment is long, detailed and worth reading in full, but here's a quick summary:

The failure of the top kill procedure tells us that the well system is more leaky and unstable than BP is letting on.

I took some time to go into a bit of detail concerning the failure of Top Kill because this was a significant event. To those of us outside the real inside loop, yet still fairly knowledgeable, it was a major confirmation of what many feared. That the system below the sea floor has serious failures of varying magnitude in the complicated chain, and it is breaking down and it will continue to.

Even if BP actually manages to cap the main break, the pressurized oil will just burst out through other leaks below the sea floor and be even harder to catch than it is now. Yet as long as the oil continues to flow through the main break, that flow will continue to erode the damaged well casing.

The breakdown of the seabed under the 450-tonne blowout preventer could result in the entire structure collapsing into an oil-spewing sinkhole, at which point the current rate of flow will look like a mere trickle by comparison.

[BP] have shifted from stopping or restricting the gusher to opening it up and catching it. This only makes sense if they want to relieve pressure at the leak hidden down below the seabed ... and that sort of leak is one of the most dangerous and potentially damaging kind of leak there could be.

This scenario puts BP in a race against time. They need to drill the relief wells to catch the oil coming out and relieve pressure on the main line, which they can then safely cap. The question is: will BP complete the relief wells in time to prevent a collapse?

Of course, I Am Not An Oil Geologist (IANAOG), but as Sharon Astyk writes on Scienceblogs:

This one passes my smell test, which is usually pretty good. That doesn't mean I claim commenter Doug R is right; it means I think his information is interesting enough to be worth exposing to a wider audience for clarification or correction.

In support of this, TOD is frequented by oil geologists and engineers, and if DougR's comment were way off-base, someone would have called him out on it by now.

It doesn't help that the Government officials are helping BP to block journalists from investigating and covering the disaster even as they remain tight-lipped about what is actually happening. In the vacuum created by this information blackout, all that remains is plausible scenario-building by shrewd observers piecing together the snippets that are available.

Ryan McGreal, the editor of Raise the Hammer, lives in Hamilton with his family and works as a programmer, writer and consultant. Ryan volunteers with Hamilton Light Rail, a citizen group dedicated to bringing light rail transit to Hamilton. Ryan writes a city affairs column in Hamilton Magazine, and several of his articles have been published in the Hamilton Spectator. He also maintains a personal website and has been known to post passing thoughts on Twitter @RyanMcGreal. Recently, he took the plunge and finally joined Facebook.

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By jasonaallen (registered) - website | Posted June 17, 2010 at 16:00:31

What did Micheal Greer (name?) say on the Archdruid Report about a month ago would be the absolute worst case scenario? "The death of every multicellular organism in the Gulf of Mexico." if indeed all of the oil underground somehow managed to get out into the sea. Scary, scary stuff. Of course, the 'cone of silence' is hardly an exercise in reassurance. Nice to see you read all the same blogs I do. Sharon Astk is an amazing writer - if you haven't read any of her books, many of them are in HPL.

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By race_to_the_bottom (anonymous) | Posted June 17, 2010 at 16:08:37

I have to say, this is the clearest explaination of what happened that I've read. Thanks for posting, even if the disaster scenario doesn't pan out (let's hope it doesn't).

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By AnneMariePavlov (registered) | Posted June 18, 2010 at 12:02:33

http://www.ifitwasmyhome.com/

Put in Hamilton, ON to get a sense of just how big this thing is.

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By Kiely (registered) | Posted June 18, 2010 at 15:06:31

Ugh... that drives the point home AnneMarie.

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By BobInnes (registered) - website | Posted June 19, 2010 at 17:45:32

Questions on my list:
I heard BP did not use a safety device commonly used in the North Sea. What is the difference between that and the Blow out preventer mentioned above?

I heard Dutch experts offered to help but were spurned. True? Why?

I heard that Russia solved a similar problem by detonating a nuke above the well, presumably to crush / compact everything in the entire area. This sounds somewhat better than the above scenario. Comments?

How does the environmental damage compare to the "dead zone" that apparently occurs somewhere in the area annually (caused by fertilizer runoff/algae bloom)?

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By gray fox (anonymous) | Posted June 21, 2010 at 11:43:10

Just heard a report from Glen Beck: There is another well that is much deeper than BPs that is not affected by this "deep drilling" shutdown. According to Glen a major portion of this well is owned by George Soros(sp). This whole mess going to end up more political than ecological!!!!

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By Cityjoe (anonymous) | Posted June 25, 2010 at 01:46:23

According to some news sources, the oil dispersants applied using airplanes by B.P.have cause the oil to be absorbed into the atmosphere, & it has recently rained oil inland in Louisiana. So contamination could be much worse than imagined.

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