As BP readied another attempt to slow oil gushing into the Gulf of Mexico, two congressmen said Tuesday that the company's internal investigation into the spill has identified new warning signs of problems before the April 20 explosion that brought down the Deepwater Horizon rig.
Reps. Henry Waxman and Bart Stupak said in a committee memo that the warning signs include an unexpected loss of fluid from a pipe known as a "riser" five hours before the explosion. That suggests there could have been a leak in the blowout preventer.
Engineers conducting tests on the system reduced the pressure to one of the lines to zero, while the pressure on the drill began to build. The memo says BP's investigator indicates that may have been a "fundamental mistake" because the rising pressure was an "indicator of a very large abnormality."
The information provided to Congress by BP shed more light on the timeline of events that preceded the rig explosion. Congressional aides said it identifies several new warning signs of problems:
- 51 minutes before the explosion, more fluid began flowing out of the well than was being pumped in.
- 41 minutes before the explosion, the pump was shut down for a "sheen" test, yet the well continued to flow instead of stopping and drill pipe pressure also unexpectedly increased.
- 18 minutes before the explosion, abnormal pressures and mud returns were observed, and the pump was abruptly shut down.
The data suggests that the crew may have attempted mechanical interventions at that point to control the pressure, but soon after, the flow out and pressure increased dramatically and the explosion took place.
Preparing for "top kill"
Five disastrous weeks after the rig explosion, BP was poised to try again to contain the catastrophic spill but warned that its latest plan to plug its gushing oil well may be delayed or abandoned.
BP engineers plan on Wednesday to inject heavy drilling fluids in the mile-deep well, a tricky maneuver and its latest bid to halt the flowing oil that has shut down fisheries and soiled coastline.
BP executives have repeatedly stressed the so-called "top kill" procedure is a complex process that has never been attempted before at such depths.
Before engineers try to seal the well, scientists will run diagnostic tests to make sure the top kill procedure does not backfire and make the oil leak worse, BP senior vice president Kent Wells told reporters.
"What we learn during this diagnostic phase will be crucial to us," said Wells, whose London-based company has seen around 25 percent, almost $50 billion, wiped off its market value.
Engineers were doing at least 12 hours of diagnostic tests Tuesday. They planned to check five spots on the well's crippled five-story blowout preventer to make sure it could withstand the heavy force of the mud. A weak spot in the device could blow under the pressure, causing a brand new leak.
Wells cautioned that engineers are speeding through a planning process that would normally take months. He warned that the top kill could be delayed or scuttled if Tuesday's pressure readings are bad.
Company executives said on Monday the procedure had only a 60 percent to 70 percent chance of working.
"We have to be careful in terms of setting expectations," Wells said.
BP said Wednesday it has agreed to continue to broadcast a live video of its leaking undersea well during the top kill procedure. There were earlier concerns that it would stop the live feed.
"Throughout the extended top kill procedure — which may take up to two days to complete — very significant changes in the appearance of the flows at the seabed may be expected. These will not provide a reliable indicator of the overall progress, or success or failure, of the top kill operation as a whole," the company said in a statement.
Meanwhile, U.S. Interior Secretary Ken Salazar on Tuesday ordered an investigation of whether his agency failed to properly oversee the oil rig involved in the spill, in light of a new report revealing ethical lapses under prior administrations.
The report found it was common before 2007 for Minerals Management Service employees at a Lake Charles, La., district office to accept gifts from energy company representatives.
After days of lambasting the company's handling of the spill, the Obama administration appeared to step back from Salazar's threat on Sunday to "push out" BP if it did not do enough to plug the leak.
The U.S. government needs BP's deepwater technology to try to shut off the oil well, said Carol Browner, President Barack Obama's adviser on energy and climate change.
Obama is dealing with a political hot potato over the failure to control the leaking well, with analysts warning that voters may punish his Democrats in November elections widely expected to erode the party's control of the U.S. Congress.
Obama will visit Louisiana on Friday to inspect efforts to combat the spill, the White House said, adding that the federal government had deployed more than 1,200 vessels and 22,000 personnel in "one of the largest responses to a catastrophic event in history."
The administration has deflected calls for it to take charge of the operation, saying it is BP's legal responsibility to cap the leak and contain the spreading spill. It stresses that federal authorities have oversight in the operation.
But, state and local officials in affected states like Louisiana have been critical of that approach. Frustrated by BP's failure to seal the well and disperse the oil, they want Obama to take more direct, forceful action.
"He needs to step up to the plate, put somebody in charge that will protect the wetlands and will keep this oil out," said Billy Nungesser, president of Plaquemines Parish, where sheets of heavy oil have already washed into marshlands.
Oil flow uncertainty
Since the April 20 explosion that sank the Deepwater Horizon rig and killed 11 workers, the blown-out well beneath the surface has spewed millions of gallons of oil into the Gulf in what may be the United States' worst-ever oil spill.
With oil and tar balls from the spill now soiling more than 70 miles of Louisiana's 400-mile coastline, the U.S. government has declared a "fishery disaster" in the waters off Louisiana, Mississippi and Alabama, making those states eligible for special federal assistance.
Commercial fishing, shrimping and oyster harvests have been shut down for weeks along much of the U.S. Gulf Coast, home to a $6.5 billion seafood industry. Louisiana's industry alone accounts for up to 40 percent of the U.S. seafood supply and more than 27,000 jobs.
Besides the top kill option, BP said on Tuesday it was preparing another control method, a lower marine riser package cap containment option, to try to capture and siphon off the oil flowing from the ruptured well.
If the short-term efforts fail, it will take BP several months to drill a relief well to stop the leak.
About 1,000 people arrived in Jackson, Miss., on Tuesday to attend a memorial service for the 11 workers killed in the rig explosion.
The memorial, held in the Jackson Convention Complex, began with the Joyful Gospel Choir singing "This Little Light of Mine." The stage was adorned with a cross and 11 bronzed hard hats, each representing one of the workers who died.