First the good news, then the bad news. Well, first the bad news that precedes the good news.
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\nBP has put a cap on the well, but a crucial test of the cap was delayed because of an unexpected leak. But basically, this is good news, the cap is on.<\/p>\n
The cap is not closed … the well is still gushing oil. But once they close the third of three valves on the cap, the well will be sealed. Then over coming weeks or months, relief wells in the same oil deposit can extract enough underground oil to make this well less of a threat.<\/p>\n
But …<\/p>\n
There is a possibility that this could go terribly wrong. When the third valve (the “kill” valve) is shut, the pressure inside the well should increase. That is good. But, once the pressure increases, it is possible that the oil that is in this well will break through to a different geological zone than where it is currently confined. Then, leak out into the sea.<\/p>\n
This is a bit like balloon that is losing air from the valve. If you plug the valve you stop the loss, but if the balloon explodes, then you are royally, totally, screwed. If something like that happens with the well, there will be, essentially, no way to stop the flow of oil into the gulf other than tapping a percentage of it off via the relief wells.<\/p>\n
No one is sure how likely that nearly-worst-case-scenario is.<\/p>\n
“I was gung-ho for this test and I remain gung-ho for this test,” said Adm Thad Allen, the US incident commander, on Wednesday.<\/p>\n
But he warned that nobody wanted to make an “irreversible mistake”.<\/p>\n
If the pressure testing fails, the well will be left open and oil capture to vessels on the surface will be resumed.<\/p><\/blockquote>\n