BP tests risky 'top kill' method to cap oil leak
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BP carried out final tests on Wednesday on an unprecedented deepwater “top kill” strategy that the energy company hopes will allow it to stop the flow of oil from a ruptured pipe into the Gulf of Mexico. The manoeuvre, which involves covering the leak with heavy drilling fluid and sealing it with concrete, has never before been attempted at such depth and pressure.
BP has not yet decided whether to proceed with the operation, which stands only a 60 to 70 per cent chance of success, according to chief executive Tony Hayward.
The manoeuvre carries a significant degree of risk: if engineers do not know the exact pressure in the pipeline and miscalculate the volume of drilling fluid, the intervention could actually lead to more oil being leaked.
All of BP's previous attempts to halt the flow of oil, including a giant straw to suck up the oil, have failed.
If the “top kill” cannot proceed, the company plans to re-attempt covering the oil well with a containment dome, this time sealing it in place to prevent the formation of crystals caused by cold sea water mixing with natural gas.
Hayward admits that there were “a whole series of failures” before an explosion on BP’s offshore drilling platform ruptured the underwater pipe on 20 April.
There were several warning signs in the 24 hours preceding the blast including sudden pressure rises and fluid leaks, according to a memo released by US lawmakers on Tuesday.
“It’s very clear that much more needs to be put in place to deal with this situation should it ever occur again,” Hayward said.
“It’s clear that this will be a transforming event in the history of deepwater exploration.”
President Barack Obama will travel to the affected area of the Louisiana coast on Friday, his second visit since the explosion.
Meanwhile an oil slick from a tanker damaged in a collision off eastern Singapore has been contained, officials said on Wednesday.
Six vessels have been dispatched to clean up small patches of oil sighted in waters by a naval base near Changi Airport, according to national Maritime and Port Authority.
The authority does not expect the slick to affect Singapore’s coastline.
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