BP on Wednesday started a crucial test on its ruptured oil well in the Gulf of Mexico that it hopes will lead to halting the flow of crude that has polluted the sea and shoreline since April.
Kent Wells, BP’s senior vice-president of exploration and production, said undersea robots working 1,6km below the surface had started shutting a sequence of three valves in a capping device installed on Monday.
The tests, which could last up to 48 hours, will determine whether to completely close the cap pending a permanent plug to be applied by a relief well in August.
BP began the process after getting approval from the US government, which had delayed the plan by 24 hours, citing concern that the test could irreparably damage the well and further complicate the task of plugging it.
Retired Coast Guard Admiral Thad Allen, the top US official overseeing the spill response, said the process was approved after closer analysis that reinforced confidence the test would not cause further harm.
If tests show that sealing the well might cause further damage, the capping device will become part of a complex system to capture the oil and siphon it to ships on the surface.
The decision to go ahead with the tests was taken after a day of intense deliberation that reached the level of President Barack Obama and his Cabinet, reflecting the stakes involved.
The disaster has soiled hundreds of kilometres of shoreline, shut down about a third of Gulf fisheries, put BP on the hook for billions of dollars in clean-up costs and legal liabilities, and prompted Obama to temporarily halt deepwater drilling.
Anger among Americans over the failure to halt the spill added to Obama’s political problems, distracting him from his legislative agenda and denting his popularity as his Democratic Party faces tough congressional elections in November.
Apart from the huge immediate cost to BP, the company could see its future US business threatened. In one such step, a House of Representatives committee on Wednesday voted for language in a Bill under which BP’s safety record would bar it from new US offshore oil and gas exploration leases for up to seven years.
In Brussels the European Union’s executive was planning to toughen rules covering accident prevention and liability for offshore oil drilling in response to the Gulf of Mexico spill.
Modifications
In Washington, DC, the White House said that after discussions between BP and senior government officials it had been decided that the test on the capping device “should now proceed with several modifications and safety requirements”.
The leak, which began after a deepwater rig exploded on April 20 killing 11 oil workers, is the worst offshore spill in US history.
BP and Allen said in the past they did not know whether the blow-out damaged the pipe, or casing, and cement in the well. That could allow hydrocarbons to escape and possibly burst through the seabed as pressure builds under a sealing cap.
Allen said, however, that seismic data gathered on Tuesday “removed the possibility of a negative event”, or hydrocarbons leaking out from the well beneath the seabed.
Unique experiment
Ed Markey, chairperson of the House of Representatives Select Committee on Energy Independence and Global Warming, who has closely followed the well-capping efforts, said he was hopeful but noted: “This is an experiment which has never been conducted before in the history of the planet.”
“They have to ensure that this well is strong enough to withstand the kind of pressure that will be applied to it when they complete the containment cap on the top,” he said in an interview with CNN.
Some experts had argued that BP should forego the test and keep using surface vessels to collect oil until a relief well intercepts and permanently plugs the well next month.
At least some of the oil from the well has been siphoned off to ships in the last few weeks, but that operation was halted while the tests are undertaken.
BP has said by the end of July four vessels can be hooked up and collect up to 80 000 barrels per day.
That should be more than enough to capture the whole well output, as estimates put the spill rate at between 35 000 barrels and 60 000 barrels per day.
The temporary cap now being tested is preferred as this is hurricane season and the oil-siphoning system would be interrupted, allowing oil to pour freely into the sea, if a storm blows through.
In Buras Louisiana, crabber Larry Tew said he was hopeful about the cap tests. “I think it’s going to work, until they get that relief well. I mean, they don’t have any other choice,” he said. — Reuters