Obama administration, after carefully reviewing the risks of the procedure had finally give them the approval to go-ahead. US administration also warned them not to intensify the problem by making an irreversible mistake.
The new temporary well cap consisting a 75-ton metal stack of pipes and valves, was immersed to the well on Monday, Jul 12. The cap will be able to stop oil leak either by holding all the oil inside the well machinery like a stopper, if successful. It is also expected to capture the oil and siphon it to as many as four collection ships, in case the pressure is too high.
The test began on Wednesday, Jul 14 with BP shutting off pipes that were funneling some of the oil to ships on the surface, to focus the full force of the gusher into the cap. Then deep-sea robots began slowly closing, one at a time, three openings in the cap that let oil pass through. Ultimately, the flow of crude will be blocked entirely.
The company informed that the tests will be assessed every six hours to check whether the closing cap would further add damage to the well.