BP has begun integrity testing on its new 'three-ram' capping system for its Macondo oil well.
The testing which began at midday local time, is thought to take between 6 to 48 hours to find out whether it can be efficient at collecting 100 percent of the oil and gas being released.
The 'three-ram' system, which contains hydraulic valves similar to the so-called Blow-out Preventer (BOP) which failed to stop the original leak, is hoped to be a much 'tighter' cap around the Macondo well such that it can completely stop the loss of oil.
If successful, BP will claim the oil leak solved several weeks ahead of schedule as relief wells currently being drilled through 2 miles of rock would not be ready until August.
"For the duration of the test, which will be a minimum of 6 hours and could extend up to 48 hours, the three ram capping stack will be closed and all sub-sea containment systems (namely, the Q4000 and Helix Producer) will be temporarily suspended, effectively shutting in the well." said the statement from BP.
"It is expected, although cannot be assured, that no oil will be released to the ocean for the duration of the test."
BP shares rose to 410.35 at close, partially boosted by this news, and also by comments that Abu Dhabi's crown prince was considering offering its considerable sovereign wealth to BP.
"We are still thinking about it," he was quoted as saying - a move which analysts hope will allow BP to avoid any further near-term risks, and are very bullish on succeeding:
"We consider that equity-linked financing - perhaps backed by Sovereign Wealth - could prove attratice...equity dilution countered by the benefit off financial solidity." said Nomura in a recent note.
The Japanese company is advising clients to aim for a 'high 400' share price on the energy company.