Officials Call Results of Well Test Encouraging

Officials Call Results of Well Test Encouraging
By HENRY FOUNTAIN
Copyright by The Associated Press
Published: July 16, 2010
http://www.nytimes.com/2010/07/17/us/17spill.html?_r=1&hpw


A day after BP closed off the flow of oil from its runaway well in the Gulf of Mexico, officials said the signs from a crucial test of the well’s condition were encouraging.

Pressure readings in the well rose significantly in the 24 hours after the valves were closed on a cap at the top of the well, an indication that the well was in good shape. But officials voiced caution, saying that they had expected that the pressure might rise even higher, and that the possibility of damage from the April 20 blowout could not yet be ruled out.

Another possibility, they said, is that the reservoir has been depleted by three months of gushing oil.

“This is generally good news,” Thad W. Allen, the retired Coast Guard admiral who is overseeing the spill response, said Friday afternoon, about 24 hours into what was expected to be at least a 48-hour test. “But we want to be careful not to do any harm or create a situation that could not be reversed.”

He said that so far the test results were ambiguous, and that the possibility remained that the well had been breached and that oil and gas were escaping into the surrounding rock and perhaps even into the gulf. But there were no visible signs of a leak.

The test, which ended — at least temporarily — what had been a three-month gusher, is intended to determine whether the well can withstand pressure from the sealing cap.

The procedure will continue in six-hour increments, Admiral Allen said, and new data will be reviewed by scientists and engineers from the government, BP and other companies. He said there would be “enhanced monitoring” of the seabed, including acoustic tests that could detect small amounts of methane bubbling into the water, which would be evidence of damage to the well.

At the White House earlier Friday, President Obama cautioned against concluding that the corner had been turned in the oil disaster, which began with the explosion and sinking of the Deepwater Horizon drill rig. He said it was still possible for there to be complications that “could be even more catastrophic” than the original leak.

Appearing in the Rose Garden before taking off for a short Maine vacation, Mr. Obama said all decisions about the fate of the well would be based on science, “not based on P.R., not based on politics.”

Kent Wells, a senior vice president of BP, said the company was watching the seafloor with cameras on robotic submersibles and using sonar and other equipment to look for leaks. So far, he said, “there is no evidence that the well doesn’t have integrity.”

When the test began, Admiral Allen said, pressures increased in a way that would be expected if the well was undamaged. But the level reached was lower than scientists had predicted if the well was intact. And pressures are now rising very slowly.

A breach could be one reason for the lower pressure readings, he said. But a more benign explanation would be that so much oil had spewed from the out-of-control well that the reservoir, 13,000 feet below the seabed, had been depleted.

“The pressure buildup we’re seeing is consistent with modeling we did around reservoir depletion,” Mr. Wells said. “The longer we model these trends, the more we’ll convince ourselves that that’s the case.”

At some point — perhaps after 48 hours, as originally planned — a decision will be made about what to do with the well over the near term, until a relief well is finished that will permanently plug it. He said leaving the valves closed beyond the test remained a possibility.

But, Mr. Wells said, if the monitoring detects oil or gas coming up through the sea floor, engineers could reopen the well immediately.

“At least initially that would involve some venting of oil into the gulf,” he said. “We’re hopeful that’s not going to be the case.”

Peter Baker contributed reporting from Washington and Liz Robbins from New York.