NEW ORLEANS—Introducing two more pieces of oil-industry lingo - "static kill" and "bullheading" - to the American public, BP began forcing mud down the throat of its blown-out well Tuesday in hopes of permanently sealing the biggest offshore leak in U.S. history.
The effort could continue through Thursday, and engineers won't know for more than a week if it choked the well once and for all.
A 75-ton cap placed on the well in July has been keeping the oil bottled up inside over the past three weeks, but that is considered only a temporary measure. BP and the Coast Guard want to plug up the hole with a column of heavy drilling mud and cement to seal it off more securely.
The static kill - also known as bullheading - involves slowly pumping mud down lines running from a ship to the top of the ruptured well a mile below. BP said that may be enough by itself to seal the well.
But Allen made it clear that to be safe, the gusher will have to be plugged up from two directions. He said the 18,000-foot relief well that BP has been drilling over the past three months will be used later this month to execute a "bottom kill," in which mud and cement will be injected into the bedrock 2½ miles below the sea floor.
"There should be no ambiguity about that," Allen said. "I'm the national incident commander and this is how this will be handled."
Over the past few months, with each failed attempt to stop the leak, the American public has learned some of the oil industry's lingo, including "top kill," which is similar to the static kill, "top hat," and "junk shot," an attempt to clog up the well with golf balls and rubber scraps.
Before the cap was lowered onto the well, 172 million gallons of crude flowed into the sea, unleashed by the April 20 explosion aboard the drilling rig Deepwater Horizon that killed 11 workers.
BP won't know for certain whether the static kill has succeeded until engineers can use the soon-to-be-completed relief well to check their work.
Allen said the task is becoming more urgent because peak hurricane season is just around the corner. Tropical Storm Colin formed far out in the Atlantic on Tuesday, but early forecasts say it will travel toward the East Coast rather than the Gulf. And while the cap appears to be holding tight, the static kill would give scientists more confidence the well won't leak again, he said.
"The quicker we get this done, the quicker we can reduce the risk of some type of internal failure" of the massive cap, he said.