BP to make decision on 'top kill' plan to stem oil leak

Advertisement

Underwater video shows tests on the seabed ahead of a plan to plug the leak

The oil company BP is to decide on whether to carry out a new plan to try to stem the leaking Gulf of Mexico oil well, the chief executive has said.

Tony Hayward said the procedure would begin on Wednesday if considered safe.

Teams have been carrying out diagnostic tests to ensure the "top kill" method - in which mud is pumped into the well - is feasible and will not backfire.

Meanwhile, a congressional memo has revealed warning signs were present in the hours before the rig exploded.

According to the document, BP officials told congressional investigators on Tuesday that a decision to continue drilling after unusual pressure readings may have been a "fundamental mistake".

BP said the buildup of pressure was an "indicator of a very large abnormality" in the well, the memo by representatives Henry Waxman and Bart Stupak said.

Problems were also identified with equipment including the blowout preventer - meant to shut down the well in the case of emergency - and potential gas leakage in the hours prior to the 20 April explosion, the memo said.

Heavy fluids

BP is under intense pressure to succeed with its latest attempt to stem the leak, after previous measures failed.

"Later this morning I will review that with the team, and I will take a final decision as to whether or not we should proceed," Mr Hayward told the US network NBC's Today show.

TOP KILL PROCEDURE

Continue reading the main story

• Drilling mud pumped from surface
• Goes into blowout preventer
• If pressure and density sufficient, oil and gas flow stops
• Well then filled with cement

What is a 'top kill'?

"I have to say that it will be a day or two before we can have certainty that it's worked."

If the new procedure is used, heavy drilling fluids - such as mud - will be injected into the well about a mile (1.5km) underwater.

Engineers hope to follow this with cement, designed to seal the well.

The company has said they estimate a 60-70% chance of success.

Officials say the method has been used before in other areas of the world, but not at the depths required to stem the oil from the Deepwater rig, which sank after an explosion last month.

If the operation goes ahead, it can be watched via a live video stream of the site, which currently shows plumes of oil and gas escaping from the well.

A conservative estimate of the amount of oil escaping is about 5,000 barrels (210,000 gallons, 795,000 litres) a day while some scientists say it could be many times greater.

The US government has declared a "fishery disaster" in the seafood-producing states of Louisiana, Mississippi and Alabama.

A massive containment and clean-up operation is under way, as the oil reaches the beaches and vulnerable marshlands of a 150-mile stretch of coast.

Some workers involved in the operation are complaining of health problems after contact with oil and chemical dispersants, the Los Angeles Times reports.

The fishermen, who say they are suffering from nausea, dizziness and breathing problems, told the paper they were not issued with special equipment but were simply told by BP not to pick up oil waste.

Louisiana Congressman Charlie Melancon has urged the federal government to set up mobile clinics in rural area to treat those affected, the paper reports. BP has said conditions are being monitored.

'Plug the hole'

President Barack Obama is due to make his second visit to the Gulf of Mexico region on Friday.

Ultra-deepwater rigs and other equipment are at the site

Aides quoted him as telling senior government officials: "Plug the damn hole."

In the tests which began on Tuesday, five spots on the well's crippled five-story blowout preventer were being checked to make sure it could withstand the heavy force of the injection.

A weak spot in the device could blow under the pressure, causing a brand new leak.

Oil industry experts quoted by Reuters news agency gave the "top kill" procedure a 50-50 chance of working.

BP has been drafting plans for the "top kill" for weeks but had to delay it several times as crews scrambled to assemble the equipment at the site 50 miles (80km) off the Louisiana coast.