BP aims to plug gulf oil well for good with two-pronged 'kill' shot
Monday, August 2, 2010; 4:41 PM
BP plans to begin easing mud into its runaway well in the Gulf of Mexico by Monday night, a preliminary step in a "static kill" procedure that potentially could kill the Macondo well by midweek.
First comes what BP calls an injectivity test. Mud will be pumped into the well from a surface ship at a gentle rate of one barrel a minute, then two barrels a minute, then three, as engineers monitor pressures and look for signs that the rogue oil is being forced back into the source rock 2 1/2 miles below the seafloor.
"We want to confirm that we can inject the oil that's in the well bore back into the reservoir," BP Senior Vice President Kent Wells told reporters in a conference call Monday.
Engineers Monday afternoon hit a minor snag in the form of a leaking valve on the Q4000, the surface rig that will handle the static kill. The repair job was expected to delay the injectivity test only for a few hours.
If all goes as hoped with the diagnostic test, BP will then go forward with the static kill, 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 into the blowout preventer that sits on the wellhead. If the oil is crammed back into the reservoir, BP engineers and government scientists will then have to decide whether to follow the mud shot with a plug of cement.
They might, however, decide to hold off on the cement until they hit Macondo at its base in the more laborious "bottom kill," in which mud and cement will be injected into the well through a relief well that engineers began drilling at the beginning of May.
If all goes perfectly, the one-two mud punch will literally be overkill. The static kill will terminate Macondo, and the bottom kill will be more like a confirmation test, akin to poking the body to make sure it's dead.
But optimism has been a dangerous attitude throughout the oil spill disaster, and the federal point man for the spill response, retired Coast Guard Adm. Thad Allen, has warned against complacency. "We should not be writing any obituary for this event," Allen said late last week.
As he delivered the latest update on the static-kill plan Sunday afternoon, he also defended the government's decision to let BP and its contractors use vast quantities of dispersants. He said that the goal of reducing the amount of dispersant used was "generally met" and that the government's field commander made decisions to allow additional dispersant on a case-by-case basis.
Although the environmental crisis has hardly passed, there is a sense these days among BP engineers and government scientists that they've got the well in a headlock. The disaster began with cascading failures and continued with cascading disappointments as attempts to kill or contain the gusher never quite worked. But since July 15 the well has been shut in, thanks to a 75-ton cap lowered onto the re-configured chimney atop the damaged blowout preventer.
The well has since passed an "integrity test" and, according to Allen, shows no sign of squirting oil and gas into the rock formation or up into the gulf.
The positive turn of events has led to a change in the endgame. The static kill has emerged as a potential fix that could take the pressure off the relief-well job. With hurricane season about to hit its busiest stretch, officials have feared that a tropical storm could force the rig drilling the relief well to disengage and sail away temporarily, delaying the termination of Macondo.