BP is working on a new way to seal off permanently its leaking Macondo well in the Gulf of Mexico, company officials said.
Engineers are preparing a so-called static kill, which is similar to the unsuccessful “top kill” BP tried two months ago.
The most recent idea is to pump heavy drilling “mud” into the well through one of the open valves in the blow-out preventer and then to seal the well by injecting cement into it.
“We’re still very much in the design and planning phase,” said Kent Wells, BP vice-president. “We’ve got some real experienced teams working on this over the next couple of days.”
US officials have kept up the pressure on BP to find a permanent solution to stop the leak following the company’s success last week in halting almost all the spill by installing a containment cap on the well.
However, the officials admitted late on Monday that seepages they had raised as a serious concern were not related to the well.
Admiral Thad Allen, the incident commander, on Tuesday confirmed BP’s latest efforts, telling journalists: “There’s some discussion that there might be some way to do a static pumping of mud into the top that would suppress the hydrocarbons.”
While the company searches for new ways to deal with the well that has been leaking since the April 20 Deepwater Horizon rig explosion, it is continuing to drill a relief well that is expected to kill the well completely by the middle of next month.
On Tuesday US President Barack Obama is expected to raise another BP-related controversy with David Cameron, UK prime minister.
Mr Obama is expected to ask about the circumstances surrounding last year’s release of Abdel Basset al-Megrahi, the Libyan convicted of bombing a Pan-Am flight over Lockerbie, Scotland, in 1988. Mr Cameron, who opposed the release, has insisted that the decision of the Scottish Executive was not influenced by BP lobbying.
Q&A: Latest plan has better prospects but is still not risk-free
BP’s engineers have come up with yet another new idea for tackling the blown-out Macondo well: the “static kill”. How is it supposed to work?
The technique is similar to the “top kill” that BP hoped would allow the well to be sealed back in May. Heavy drilling fluid, or mud, would be pumped into the blow-out preventer – the stack of valves on the seabed that failed in the accident – and down the well, to push back the oil and gas.
When the mud reaches the bottom of the hole and the flow of oil is under control, cement can be pumped in to seal the well shut. That was the idea in May, and is the proposal again on Wednesday.
So why should this succeed when the top kill failed?
The difference is the containment cap that BP has now fitted to the top of the blow-out preventer, with a tight seal that is preventing any oil escaping. The top kill was attempted against a flowing column of oil and gas, pouring out of the hole at a rate of 35,000 barrels or more per day. The static kill would be deployed against a column of oil and gas that is already under control, and where the flow of oil has declined after three months of production. During top kill, much of the mud being pumped into the hole simply escaped out of the top of the broken blow-out preventer. With the cap on, that cannot happen.
Is the procedure risk-free?
No. Pumping mud into the well would increase the pressure inside the hole, raising the risk of a blow-out either above or below the seabed. Neither BP nor the US government has yet seen any sign that closing the containment cap has led to oil escaping from the well and leaking out from the sea bed, but that is still a risk.
Is the US government happy with the decisions BP is taking?
Yes. BP acts only with the approval of US officials. Often decisions come from Steven Chu, the Nobel prize-winning energy secretary. There can be differences of opinion, but BP would not dare defy the government.
What about the relief wells? Are they still the only permanent solution?
Yes. Drilling the first well was halted when the cap was closed last week, as a precaution against oil and gas escaping into the new well. It was restarted again on Saturday.
So when will the well finally be sealed?
The first half of August has looked like the most likely date when the well can be sealed, and that is still the case on Wednesday. For as long as the cap remains closed, however, there will still be no more oil escaping into the waters of the gulf.
Ed Crooks, London
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