The company’s chief executive Tony Hayward said he expected the process would catch the ‘vast majority’ of oil once it was up to full speed - but the US government estimates between 12,000 and 25,000 barrels a day could be leaking from the well.
A lower marine riser package (LMRP) containment cap was installed over the well on 3 June, and 10,500 barrels of oil and 22 million standard cubic feet of natural gas were captured on 5 June. Oil and gas are still escaping through vents in the cap designed to release pressure.
BP’s chief executive, Tony Hayward, told the BBC yesterday that he expected the proportion captured ‘to be the majority, probably the vast majority of the oil’.
But a statement from the company this morning said: ‘The LMRP containment cap never before has been deployed at these depths and conditions, and its efficiency and ability to contain the oil and gas cannot be assured.’
The firm estimates the cost of the leak response has reached over $1.6bn (£1.1bn), including containment, relief well drilling, grants to the Gulf states, claims paid, and federal costs.
The US government is reportedly looking at barring BP from receiving future federal contracts. The company is the biggest provider of oil and gas to the US military, with contractsworth over $2bn (£1.4bn) a year.
Admiral Thad Allen, the US coastguard official in charge of the US government’s response to the spill, told CBS that the fight to contain the oil would last for several more months.
‘I’m hoping we catch as much as we can, but I’m withholding any comment until we know production is at a full rate and we close all those vents of oil, and we see what’s coming out around the rubber seal at the bottom,’ he said.
Engineers are pumping nitrogen and methanol into the cap in an attempt to stabilise pressure and combat the cold temperature at the 5,000ft (1,500m) depths. If the pressure is successfully lowered, the vents will close and the flow of oil will increase.
A previous attempt to cap the well failed because seawater mixed with the gas to form ice-like hydrates that blocked the flow of oil to the drill ship.
BP intends to install a more permanent and flexible LMRP cap system by early July involving a free-floating riser ending around 300 feet below sea level. It hopes this will allow the system to be more easily disconnected and reconnected during the upcoming hurricane season-which US officials predict could be the worst on record.
The firm also plans to take oil and gas from the failed Deepwater Horizon blow-out preventer (BOP) using a separate riser, which it hopes will be in place by mid-June. Relief wells begun in May are not expected to be complete until August.