BP reported Sunday that its containment cap is now collecting 420,000 gallons a day, saying that was a 'majority' of the oil. But the flow rate in the Gulf oil spill is still uncertain, and BP has failed to live up to its optimistic predictions in the past.
BP Chief Executive Tony Hayward told the BBC Sunday that the cut-and-cap maneuver is now collecting 420,000 gallons of oil a day – 40 percent more than it was collecting Saturday.
The improvement raises hope that the containment cap now fitted atop the well might successfully collect as many as 630,000 gallons of oil daily – the highest amount that tanker vessels on the surface can collect.
Mr. Hayward bullishly said he thought the cap was now collecting “the majority, probably the vast majority of the oil."
Yet the comments will be viewed with some caution. BP has failed to match its own optimistic forecasts in the past:
- Hayward said there was a 60 percent to 70 percent chance that the “top kill” maneuver of two weeks ago would seal the well. It failed.
- The use of a siphon stuck into the riser pipe three weeks ago prompted Hayward to say: “I do feel that we have, for the first time, turned the corner in this challenge.” The siphon was later abandoned.
- Early estimates of the oil flow rate were pegged at 210,000 gallons a day – 5,000 barrels – which according to current estimates, might have been four times lower than the actual rate. Some scientists say that even the current estimates are conservative.
The actual flow rate
The containment cap could offer some greater clarity on the actual flow rate. As engineers learn how much oil they are capturing, they’ll be able to compare that with how much they see escaping.
"Hopefully we'll start moving those ranges into a more acceptable representation of what's actually flowing, and the best way to do that is to get a good flow rate of production because once you know what you are producing every day, that's a known quantity you can take off the table," said Coast Guard Admiral Thad Allen, national incident coordinator, in a press conference Saturday.
At the outset of the operation, BP engineers said they did not expect to collect all the oil with the containment cap. Moreover, current flow estimates suggest that as many as 800,000 gallons of oil might be leaking into the Gulf each day, meaning that even in a best-case scenario the containment cap might still allow 170,000 gallons to leak into the Gulf daily. That would be 80 percent of the early 210,000 gallon estimate.
Even at the current capture rate of 420,000 gallons a day, though, the containment cap would represent BP’s greatest success so far.
The company has virtually abandoned the idea of actually stopping the well before a relief well is finished no earlier than August. That leaves collecting the oil at the source as the only way to slow the spill’s environmental destruction.
Cutting the flow rate – perhaps in half – would be a step toward that goal. The oil slick is now moving eastward, with parts of the slick reaching the beaches of Alabama and Florida. There is further concern that, as it expands, the slick be caught in the Gulf’s loop current, which might carry it out of the Gulf and up the Atlantic coast.
The damage to undersea ecosystems, from deep-water coral reefs to the plankton that undergird the food chain, is so far virtually unknown.
BP not done yet
Heyward said BP was planning to implement further measures this week to trim the flow of oil into the Gulf.
First, the tubes used to pump in drilling mud during the failed “top kill” effort would be retasked as additional siphons.
Second, BP plans to build a new riser pipe – starting at the cap and ending about 300 feet below the surface – that would make it easier to start and stop oil-collection operations. Currently, it would take almost a week to reconnect to the containment cap, which is 5,000 feet down, if the connection to the surface was severed. Once a new riser pipe is finished next month, ships would be able to reconnect within two days.
This is designed to be a contingency for hurricanes, when tanker vessels might have to detach from the containment valve.
The containment cap effort suggests that BP is gradually learning from its mistakes. Engineers have proceeded cautiously in closing vents atop the cap, wanting make sure the conditions are right before acting. A previous attempt to contain the oil failed when ice crystals formed in a dome set over the well.
Indeed, each additional step by BP is adding to scientists’ limited understanding of conditions on the sea floor – a place so remote and poorly studied that some call it “inner space.”