Misunderstanding 'hampered oil spill clean-up efforts'

Critical time was wasted during initial efforts to slow the Gulf of Mexico spill due to a safety valve being wrongly plumbed, a senior BP official claimed.

Harry Thierens, vice president at the oil giant, told a US panel he was “astonished” to learn that the blow-out preventer was changed by contractor Transocean.

It meant that the work of underwater robots trying to trigger the device was futile in the early days after the accident.

The April 20 blow-out in the Gulf of Mexico resulted in the deaths of 11 workers and the worst environmental disaster the region ever saw.

Since the accident, BP came under attack for prioritising speed and cost-cutting above safety. But an investigating panel in Houston, Texas, heard testimony suggesting that rig contractors Halliburton and Transocean may also be at fault.

It emerged yesterday during Mr Thierens’ evidence that Transocean, hired by BP to drill the well, had difficulty providing details of the changes it made to the blow-out preventer, even after it emerged that they were made.

On April 25, five days after the explosion, Mr Thierens wrote in his logbook: “Some confusion in TEO (Transocean), regarding details around the control system. No Transocean approved drawing available.”

It later emerged that the device suffered other problems, including pipes being run to different places.

This meant that the early work by the underwater robots was futile.

“I spoke frankly about the seriousness of this issue and quite frankly was astonished that this could have happened,” Mr Thierens wrote.

He added that Transocean cementer Billy Stringfellow was “clearly emotional” and told the BP man “this stack is plumbed wrong”.

Mr Thierens told the panel that by this time he had “lost faith” in the plumbing of the device, but in any event the blow-out preventer could not be triggered.

The failure of the device is central to the investigation into what caused the Gulf of Mexico’s worst ever environmental disaster.

The potential impact of the accident was felt by BP yesterday, as it emerged that the firm abandoned plans to drill in the Arctic, possibly as a result of its tarnished reputation.

The Guardian reported that the firm was no longer planning to try to win an exploration licence in Greenland.

“We are not participating in the bid round,” a spokesman told the newspaper without giving further details why.