Thad Allen, the official appointed by Barack Obama to lead the government’s response to the disaster, said leaks detected over the weekend did not threaten the well.
He said the seepage of gas from the seabed probably had nothing to do with the well. Oil and gas are known to ooze naturally from fissures in the bottom of the Gulf of Mexico.
Speaking at a news conference last night he said: “The small seepages we’re seeing do not indicate at this point a threat to the well bore.”
Yesterday he gave BP another 24 hours to keep the containment cap on the ruptured well closed, during a terse exchange of words between the company and the government over the handling of the crisis. Today Allen said BP could keep the cap closed for at least another 24 hours as long as the company remained on alert for leaks.
Allen sent a stiff letter to BP on Sunday night, ordering the oil giant to continue seismic and sonar monitoring around the well to try to get a better picture of what was happening now that the flow of oil had ostensibly stopped.
He said the company had an obligation to inform him of any problems within four hours of any seepage being detected.
“I remain concerned that all potential options to eliminate the discharge of oil be pursued with utmost speed until I can be assured that no additional oil will spill from the Macondo well,” he wrote.
At the heart of the dispute is anxiety about what is happening under the seabed. The government fears oil may be leaking below the surface, and that if left unchecked this process could cause graver problems, including the collapse of the well.
In a statement yesterday, Allen said he would ensure BP continued to assess whether keeping the cap closed could “worsen the overall situation”.
BP, on the other hand, has pointed out forcefully that the antidote to seepage – reopening the cap and allowing the oil to flow upwards again to specially designed oil-capture vessels – would involve allowing oil to spew once more into the Gulf for at least another three days.
That would undo the sense of progress achieved since last Thursday, when the cap was fully locked down and the oil flow stopped.
The main way of tracking what is happening to the well – its “integrity”, as it is known in the business – is to gauge the pressure of the oil that is flowing up the pipe. BP said yesterday that the level was about 6,800lbs per square inch (psi) and increasing at around 2 psi per hour.
The oil firm sees that as a positive figure, given that the quantity of oil in the reserve beneath the sea floor has already been depleted substantially, more than 4m barrels having spewed into the gulf. But the Obama administration thinks this is lower than it should be and would like to see the pressure rise to around 8,000 psi, which would show conclusively that there were no leaks. Until that figure is reached it will remain cautious, mindful of the political damage that has been caused to Obama’s presidency as a result of his early handling of the crisis, which was criticised for being soft on BP.
Both sides agree that the disaster will not be fully over until the well has been permanently capped through the drilling of relief wells. BP said the first relief well had reached 5,450 metres, and the second 4,840 metres. The relief wells could join up with the original Macondo well as early as next week, at which point heavy mud and then concrete will be pumped down the original to block it forever.
It also emerged today that Donald Vidrine, who was in charge of operations on the Deepwater Horizon oil rig at the time of its explosion on 20 April, will not testify before a key hearing in the US. He cited health issues for his inability to attend a hearing in Louisiana held by the US department of the interior and the US coastguard, which began yesterday.
It is the second time he has declined to give his account of events on the day of the disaster, after his failure to attend hearings in May.