BBC NEWS

15 July 2010 Last updated at 21:11

BP says it has temporarily stopped oil flowing into the Gulf of Mexico from its leaking well.

It is the first time the flow has stopped since an explosion on the Deepwater Horizon rig on 20 April.

The well has been sealed with a cap as part of a test of its integrity that could last up to 48 hours.

BP executive Kent Wells said the oil had been stopped at 1425 local time (1925 GMT) and he was “excited” by the progress.

“It is very good to see no oil go into the Gulf of Mexico,” said Mr Wells.

But BP is stressing that even if no oil escapes for 48 hours, that will not mean the flow of oil and gas has been stopped permanently.

The pressure testing is necessary to check the strength of the well. If the pressure within the cap on top is low, that could indicate oil is leaking out further down the well.

The US government’s incident commander, Adm Thad Allen, said even if it was successful, the well would be reopened and oil capture by ships on the surface would restart while a seismic test was done.

“We can go back then and put the system under pressure again. Once we are convinced we can certainly consider shutting in the well, that is always possible and we would certainly look to do that.”

But he emphasised that the option of shutting in the well – closing all the valves and stopping the flow – was a “side benefit” of the new capping stack.

The priority had always been to increase the amount of oil being captured and piped to the surface, he said.

Whatever happens will be a temporary solution, ahead of a relief well being used to permanently killing the original well with mud and cement.

Work on both of the relief wells is currently suspended because of the integrity test. One of the relief wells is within four or five feet horizontally and 100ft vertically of intersecting.

The pressure test was twice delayed before starting on Thursday, once while additional checks were put in place to allay fears it could make the leak worse, and on Wednesday by a leaking piece of equipment.

Meanwhile, BP continues to face political pressure in the US.

A Congressional committee has agreed measures that would ban the firm from new offshore drilling for seven years.

And in a separate move, Secretary of State Hillary Clinton has said she will look into a request by four senators to investigate allegations that BP lobbied for the release of Lockerbie bomber Abdelbaset al-Megrahi while attempting to finalise an oil deal with Libya.

The 1988 bombing of Pan Am flight 103 killed 270 people – most of them were American.

Megrahi, who has terminal prostate cancer, was freed by Scottish Justice Secretary Kenny MacAskill on compassionate grounds in August 2009 after serving eight years.

In a statement on Thursday, BP admitted it had expressed concern to the UK government about the slow progress of a prisoner transfer agreement between the two countries.

But the firm said it had taken no part in discussions on the decision to free Megrahi.

And the UK ambassador to Washington, Sir Nigel Sheinwald, said: “Claims in the press that Megrahi was released because of an oil deal involving BP, and that the medical evidence used by the Scottish Executive supporting his release was paid for by the Libyan government, are not true.”

Steps in the test 

1. The middle ram valve regulating the oil flow on top of the cap is closed
2. The kill valve is closed off
3. The choke is closed, beginning the test
4. BP and government experts will assess progress every six hours
5. But if low pressure is detected they will open the well up instantly
6. Other precautions include extra monitoring, such as by remote vehicles on the seabed

BBC NEWS ARTICLE

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