BP ignored the advice of safety critical software in an attempt to save time before the disastrous Gulf of Mexico oil spill, according to a presentation slide prepared by US investigators.
The slide in question briefly appeared on the Oil Spill Commission's website in error, but was quickly retracted. The New York Times newspaper published a screenshot of the slide, which showed at least eight "risky" steps that BP and its partners Halliburton and Transocean were judged to have taken in order to save time. Each step was "unnecessary", experts concluded.
Advanced cement modelling software, provided by BP's cement contractor Halliburton, had highlighted serious stability concerns with the well, saying more centralisers - which are used to provide space around the oil pipe casing as cement is poured in - needed to be added to ensure safety.
BP initially ordered the extra centralisers. But when the devices arrived at the rig, engineers mistakenly thought they were the wrong type. BP decided at this point to continue with the project without the additional centralisers, taking other safety steps. It also decided not to rerun the cement modelling software, and questioned the accuracy of the technology.
As the drilling proceeded, Brian Morel, engineer at BP, wrote an email to colleague Brett Cocales, saying: "Who cares, it's done, end of story, we'll probably be fine".
The project had been running late. While the site was not fully functional it was still reportedly costing nearly £1 million every day to operate.
The Oil Spill Commission previously stated the decision on centralisers appeared to highlight "a rush to completion" at the drilling site. But in a hearing last week, it also said that BP had not sacrificed safety to save money.
BP had not commented at the time of writing, but said in a Bloomberg story in August that in order "to deflect attention away from its potential role in the well blowout, Halliburton has tried to focus the public's attention on the number of centralisers used by BP in the Macondo well". It insisted Halliburton had not deemed the cement job to be unsafe, and questioned the cement slurry mix.
Halliburton declined to comment. A spokesperson at Transocean, the rig owner, said: "Transocean does not - and did not in connection with the Deepwater Horizon - operate in preference of time or cost over safety." Procedures were "designed and directed by BP's expert personnel on the rig and onshore", the spokesperson said.
The slide was not used at a key hearing this month, but was accidentally posted to the OSC website, the New York Times reported. It had been intended for the meeting, but it was not signed off by the commissioners and so was pulled at the eleventh hour.
An OSC spokesperson told the newspaper: "We wish that the slide had been part of the presentation, and the information will be used, I predict, in the future, either in our remaining meeting or in the final report."
The points in the slide were "supported entirely" by investigations conducted so far, the spokesperson said. Other potentially risky decisions taken on the rig included Halliburton not re-evaluating the cement slurry mix or waiting for foam stability results, as well as BP not running diagnostics on the well, not using a cement log and not installing additional plugs to the well.
Meanwhile, investigations have still not uncovered what happened to the blowout preventer, which sits on the well head and is intended to prevent this type of accident. Forensic examinations on the device are continuing.
In a document presented to the OSC this week, experts said blowout preventers must in the future be equipped with "diagnostic tools", similar to black boxes in aircraft. These would be used to "provide more information in the case of a blowout".
The document also concluded that better information sharing and oil spill tracking technology should have been in place at the time, and was developed frantically in response to the accident. US government emails released to the Associated Press this week showed the authorities had struggled to track and measure the size of the spill.