Gulf well has days to live, if mud-cement effort works

The next shot at killing BP's problem well in the Gulf of Mexico could begin as early as Monday night as engineers plan to pump heavy mud into the capped but still dangerous well and "bullhead" the rogue oil back into its source rock 2 ½ miles below the seafloor.

The so-called "static kill" is part of a double whammy of mud and cement that would hit the runaway Macondo well high and low in quick succession. The static kill starts at the top, firing the mud and possibly cement into the blowout preventer that sits on the wellhead.

That effort, which would take a day or two, would be followed in five to seven days by the start of the more laborious "bottom kill," in which mud and cement will be injected into Macondo through a relief well that engineers began drilling at the beginning of May.

If all goes perfectly, the one-two mud punch literally will be overkill. The static kill will terminate the well; the bottom kill will be more like a confirmation test, akin to poking the body to make sure it's dead.

The static kill is effectively the same thing as the "top kill" attempted in late May. No one is sure why that attempt failed, but BP believes the mud simply shot out the top of the well through cracks and openings in the collapsed riser pipe.

This time should be different, and easier. Hydrocarbons aren't flowing. The mud can be injected gradually. Where it will go is unclear; engineers say only that it will follow the path of least resistance. The mud weighs about 13 pounds per gallon and is much heavier than the oil, so it should push — or "bullhead" — the oil down the well toward its origin in the ancient rock more than 13,000 feet below the wellhead. Ideally, the mud will fill the well all the way to the bottom of the well bore, where the final seven-inch pipe juts into the porous Macondo reservoir.

If it works, pressure in the well slowly will drop to zero from nearly 7,000 pounds per square inch. At that point, engineers could decide to send in a large dose of cement. That would plug the well permanently at its base. BP has said Macondo, which has spewed as much as 184 million gallons since the rig connected to it blew up in April and killed 11 workers, never will be resurrected as a production well.

But there could be complicating factors.

No one is sure if oil and gas are flowing inside the pipe or outside the casing in what is called the annulus — the space between the pipe and the rock wall of the hole. Or the flow could be through both.

As a result, officials plan to proceed with the relief well regardless of what happens with static kill. The relief well is only about 4 feet laterally from Macondo, angling in gradually, with about 100 feet to go before it intercepts the annulus.