BP begins ‘top kill’ to plug oil leak

BP on Wednesday began its planned “top kill” operation (see live video feed) in the Gulf of Mexico intended to stop the flow of oil and gas from the leaking Macondo well by pumping heavy drilling fluid down the hole.

Tony Hayward, its chief executive, gave the go-ahead after approvals from the US authorities. BP has said the attempt has a 60-70 per cent chance of success, and could take two days to work. The company is also preparing further ways to stop the flow if “top kill” fails.

Mr Hayward said: “The operation is proceeding as we planned it. It will be another 24 hours before we know whether or not this has been successful.”

The procedure is the latest attempt to stem the flow of thousands barrels of oil a day into the Gulf of Mexico because of an explosion on BP’s Deepwater Horizon drilling rig off Louisiana on April 20.

It began after the company’s engineers, using remotely controlled submarines, gained access to the failed blow-out preventer (BOP), the stack of valves on the seabed that was intended to prevent uncontrolled escapes of oil and gas.

After a series of tests on pressures and flow rates in the BOP, they began pumping the drilling fluid, known as “mud”, at about 1pm local time.

BP hopes to be able to pump enough mud down the hole to offset the pressure of the oil and gas being forced up from the reservoir 13,000ft below sea level. Once the leak is stopped, BP will then be able to close the well with cement, sealing it permanently.

This procedure had not been carried out offshore at such a depth before and its success could not be assured, the company said.

If the procedure goes wrong, some experts fear it could disturb the BOP, which may have partially functioned, and allow the oil to escape more quickly.

BP may also try a “junk shot”: firing material such as golf balls into the BOP to clog it up.

If the “top kill” fails, then the company will try to deploy a new container over the BOP.

AudioBP update, price of oil and carbon emissions In this week's pod: update on the BP clear up, the price of oil and how the EU could move from emissions cuts of 20pc by 2020 to 30pc. We hear from Tony Hayward, CEO of BP and Mary Landrieu, US Senator for Louisiana. Produced by LJ Filotrani Download