BP has begun crucial tests on its ruptured Gulf of Mexico oil well after a 24-hour delay.
If successful, it could mean the flow from the gushing well could be completely stopped for the first time in the three month long environmental disaster.
The tests could take up to 48 hours and entail closing the valves on the preventor, shutting in all the leaking crude so engineers can gauge the oil pressure beneath the new capping stack.
US Coast Guard Admiral Thad Allen was cautious about how the tests might go.
“ It would be terrific news if we can shut the well, but I don’t think we can say that. I think there needs to be an overabundance of caution and I don’t want anyones hopes up that we can shut this well until we can get the empirical pressure readings that e need and do a seismic survey of the sea floor and try to understand as well as we can the condition of the wellbore and casings,“he said.
If the tests indicate that sealing the well might provoke leaks elsewhere, the current capping device will remain and become part of the system siphoning the oil up to ships on the surface.
The leak, which began after a deepwater rig exploded on April 20 killing 11 oil workers is the worst offshore spill in US history.