By Joel Achenbach
Washington Post Staff Writer
Friday, July 16, 2010; A01
The gusher is gone. The plume is off the well. BP's Macondo well isn't dead yet, and it may be back in a flash, but at 3:25 p.m. Eastern time Thursday it ceased to spew oil into the Gulf of Mexico.
As part of what BP calls an "integrity test," a robotic submersible slowly closed a valve on the well's new sealing cap. That choked the flow until the plume, a fixture of cable TV and many a nightmare, disappeared. The technological breakthrough came 87 days into the crisis, which began with the April 20 blowout that killed 11 workers and sent the burning rig Deepwater Horizon to the bottom of the gulf.
BP could nix the test at any moment and reopen the well. Whether the well remains "shut in," to use the industry term, depends on the analysis of pressures in the well. Engineers and scientists hope to see high pressure hold steady during the 48-hour period allotted for the test. That would suggest that the well bore is physically intact. Lower pressure would hint of breaches in the casing and leakage into the surrounding rock.
The initial pressure readings are in an ambiguous range, and officials will have to make a difficult judgment call on whether to keep the well shut in or reopen it, according to Tom Hunter, retired director of the Sandia National Laboratories and a member of the federal government's scientific team overseeing the test.
"If it were a lot higher, it would be an easier decision to make," Hunter said.
Retired Coast Guard Adm. Thad Allen, the national incident commander, has said that a pressure reading of 8,000 or 9,000 pounds per square inch would be ideal, while below 6,000 psi might indicate leakage. Hunter, who witnessed the test from BP's war room in Houston, told The Washington Post that the pressure rose to about 6,700 psi and appeared likely to level out "closer to 7,000." He said one possibility is that the reservoir has lost pressure as it has depleted itself the past three months.
"It's just premature to tell. We just don't know whether something is leaking or not," Hunter said.
Seismic and sonar surveys will scout for evidence of oil and gas moving through the geological formations. Robotic submersibles are scrutinizing the muddy gulf floor and the base of the well's blowout preventer, looking for signs of rising hydrocarbons.
Allen issued a statement late in the day saying that, although he is encouraged by the latest developments, a return to the containment strategy "remains likely."
Reopening the well would not be a sign of failure, Hunter said, because, with the new cap -- the "3 ram capping stack" -- on top of the well since Monday night, BP has more options for capturing the hydrocarbons. As many as four ships could soon give BP the capacity to collect between 60,000 and 80,000 barrels a day, which exceeds even the highest government estimate for what's coming out of the well.
"No matter what comes out of this entire operation, we're going to be in a much better position than we were before," Allen said.
The successful start to the pressure test incited clapping, handshakes and back slaps in the war room, Hunter reported. But given past mishaps, BP engineers and government officials muted their celebration.
"We're far from the finish line here," BP chief operation officer Doug Suttles told CNN.
"It felt very good not to see any oil going into the Gulf of Mexico. What I'm trying to do is maintain my emotions. Remember, this is the start of our test," Kent Wells, BP's senior vice president of exploration and production, said in a conference call with reporters.
Regardless of whether BP and the government decide to keep the well closed at the top, the ultimate solution to the blowout is a mud and cement bottom-kill from a relief well that is four feet from Macondo laterally and has only about 150 feet vertically to drill. During the integrity test, drilling of the relief well has been suspended as a precaution against oil and gas surging into the new hole from Macondo.
Louisiana Gov. Bobby Jindal (R), leading reporters on a tour of an island the state is building to stop incoming oil, welcomed the closing of the well but said he was worried that public attention and federal help might slacken if the well remains sealed.
"This fight's not over for Louisiana," Jindal said. "It would be premature to declare 'Mission Accomplished.' " In Gulf Shores, Ala. -- a beach town that has been repeatedly hit by tar balls and gooey oil -- Mayor Robert Kraft wasn't ready to pop champagne.
"Forgive us for being a little bit skeptical, but give me 48 hours," Kraft said. If nothing goes wrong, he said, "I'll breathe."
The test had been delayed two days, first by government fears that it could backfire and then by a leak in a key component of the well's new cap. The choke line, the crucial three-inch pipe, curved like an elephant's trunk, sprang its own leak Wednesday night. Engineers swapped in a spare choke line from a surface ship. For hours Wednesday night and Thursday morning, video streams from the seafloor showed a chaotic plume of oil and gas surging from another outlet, the kill line. That was just the latest configuration of the plume, which has taken on different forms as engineers have hacked and prodded the deep-sea hardware.
A key turning point -- one that set the strategy that led to the integrity test -- came when government scientists in early June came up with a new, staggering estimate for the flow rate of 35,000 to 60,000 barrels a day. That spurred the government to demand that BP come up with a more robust set of containment measures. Allen said Thursday that, while developing this plan, it occurred to engineers that they might be able to use the new set-up to shut in the well.
Staff writer David Fahrenthold in Louisiana contributed to this report.