How much damage will the BP oil spill cause?

May 14, 2010

-Kees Willemse is professor of offshore engineering at Delft University. The opinions expressed are his own.-

Last month’s explosion at the Deepwater Horizon rig continues to result in the leakage of an estimated 200,000 gallons (910,000 litres) of oil into the Gulf of Mexico each day.

According to U.S. President Barack Obama, “we are dealing with a massive and potentially unprecedented environmental disaster”.

While the leak is extremely serious, and Obama’s words may ultimately ring true, the leak is (as yet) not one of the top 50 biggest oil spillages from either oil rigs or tankers in historical perspective:

•    Some 7-10,000 tonnes of oil are so far estimated to have leaked into the Gulf of Mexico from Deepwater Horizon.
•    The Exxon Valdez leaked some 36,000 tonnes of crude oil on the shores of Alaska.
•    The largest ever off-shore leakage of oil occurred in 1979 in the Ixtoc-1 spillage when an estimated 476,000 tonnes of oil polluted the Gulf of Mexico (Bay of Campeche).
•    The biggest ever on-shore spillage occurred in the aftermath of the 1991 Iraq War when an estimated 1.4 to 1.5 million tonnes was released in Kuwait by Iraqi military forces.

Most at risk from the Deepwater Horizon spill are the coastlines of Texas, Florida, Mississippi, Alabama, and Louisiana, including the wetlands near New Orleans where millions of migratory birds are currently nesting, and fish spawning.

The oil spill could also be catastrophic for the Gulf Coast’s substantial seafood industry, including oysters and shrimp.

To mitigate the environmental impact, measures will continue to be taken to prevent as much of the oil as possible reaching the shoreline, including setting fires to ‘burn-off’ the oil; soaking up the oil; and placing protective ‘barriers’ around shorelines.

The precise scale of the unfolding disaster remains uncertain owing to the lack of clarity over how long the leak will last.  In the worst-case scenario, as U.S. Interior Secretary Ken Salazar has suggested, the leak could continue for several more months.

Uncertainty is also increased by the fact that BP executives are reported to have admitted to members of the U.S. Congress that the amount of oil spilling could intensify — perhaps by several multiples of the current leakage per day — if they cannot cap the flow.

Hopes for a relatively early end to the leakage are resting largely upon the success of the operation to install a five-storey, 100 tonne containment dome.

The device was to be lowered by cranes around 1500 metres to the sea floor and, if possible, positioned over the two areas of leaking pipe.

If successful, the dome would serve as a giant funnel, collecting and piping it for collection on the sea surface. However, this operation has only been applied at a much smaller water depth and the first attempt to employ the device here has not been successful.

Even if successful, the dome will not stem all of the leakage (perhaps 80-90 percent of it) and there remains a risk of explosion when the oil reaches the surface because of the volatile mix of oil, gas and water.  Thus, the operation can only be a ‘holding’ one to buy time until the spillage can be shut off at the two remaining sources of the leak.

While shutting off the leakage at source will be an immensely difficult task, hopes will have been raised last week by the fact that BP successfully shut off the smallest of the three original leakages.  This was done by placing a valve over the ruptured pipe and shutting it off using a remotely controlled submarine.

The best hope of shutting off the two remaining sources of leakage is getting the blow-out preventor working again.  This is the system, which should act as an emergency cut-off to stop oil continually spilling out if a pipe is damaged, and which failed catastrophically last month.

However, the blow-out preventor is proving immensely hard to fix, in large part because of the exceptional depth of the water.  Hopes rest largely upon robot submarines re-starting the system.

In the event that the blow-out preventor cannot be fixed, relief wells have begun to be drilled that could be used to siphon off the oil leaking from the holed pipeline.

This operation will take an estimated two to three months as the drilling is taking place at 1500 metres water depth and a further 5 kilometres into the hard rock.

The relief well can also be drilled such that the shaft of the new well enters into the shaft of the existing, problematic well. A cement prop can then be inserted to stop the flow in the first well. This requires extremely accurate drilling, but that technique has been proven before.

Inevitably, all of this environmental mitigation and emergency replacement activity is proving extremely expensive.  The cost of operations to BP alone is an estimated 6 million dollars a day, and independent estimates have put the final bill at between 3 billion and 12 billion dollars.

However, the effects of this accident cannot be expressed in money terms alone, because of the growing scale of the environmental disaster if the oil spill cannot be contained soon.

Once the crisis is over, industry and government will need to make an urgent in-depth analysis of the cause of the accident to ensure that similar incidents can never happen again.


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The Canadian oil sands can finally officially pass the crown “Dirty oil” off to their rightful owners the offshore producers and shippers.

Oil sands can provide clean and environmentally friendly oil to the world for over a hundred years. This without bringing the hurt and pain to environmentally sensitive regions that do not deserve this again.

It’s unfortunate that this needed to happen for the world to wake up that an endless supply is located onshore.

Posted by BigBadOil | Report as abusive

I submitted an idea to BP a few days ago which I believe will work, to stop the leak. They already have a 78 ton metal box which they can put on top of the leak on the ocean floor. I suggest they start vacuuming mud off the sea bed and dumping the mud on top of the box. Eventually, the mud will build up a large roughly conical mound on top of, and around, the box and leak. The weight of the mud bearing down on the box will seal it effectively against the sea bed. The sheer mass of mud will counteract the overpressure of the oil from the well. The relief well currently being drilled will eventually remove the oil overpressure, so the mud can then be removed by pumps and the leak sealed in a more permanent fashion.

Posted by johnmann56 | Report as abusive

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[…] billion to $15 billion. But as Kees Willemse, professor of offshore engineering at Delft University writes “The effects of this accident cannot be expressed in money terms alone, because of the […]

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[…] billion to $15 billion. But as Kees Willemse, professor of offshore engineering at Delft University writes “The effects of this accident cannot be expressed in money terms alone, because of the […]

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Everyone is worried about the oil coming up uncontrolled from the sea bed. The biggest worrier I have seen so far is BP. Sure they are losing millions because of this oil floating up and kill fish and wildlife daily.

They are also spending millions, without comment about how much money they are spending or for that matter losing on this one site.

I’ll bet you that 99.9% of the population worried about this pollution are still buying fuel for their cars. Of those I’d guess that about 50% of these go to any other company that is not BP. Yes I can see everyone being mad and worried about this problem happening, I would just see that the support of BP while it is happening a good idea.

Sure if you wish, go to another oil company when the problem is fixed. Unfortunately, I am the occupant of an electric wheel chair 24 hours a day, 7 days a week. If I was still able to drive a vechile on the roads, until this problem is solved, I would gladly by my fuel from BP to make a donation so they can clean up ASAP.

Posted by boags | Report as abusive

If its not a blow by or fear for a blow by, its rather simple to replace the so called failing BOP. 20 years ago I presented my company a concept of an equipment to replace a failing BOP. Any way, 27 years ago I presented the oil majors Shell, Exxon and BP a concept for oil drilling; cheaper, faster and safer. Most major advances in oil drilling of the last 25 years were included in that concept; coiled, monodiameter, underbalanced, snake. So to my opinion the oil spill is a result of rather clumsy operations. best regards, www222Lu ,JvdVeen

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