BP has blamed “a sequence of failures”, including a “bad cement job” and the misreading of pressure tests by engineers, for the disastrous Gulf of Mexico oil spill.

In an internal inquiry into the April 20 disaster, published on Wednesday, the UK oil group faulted its own engineers for the accident but also said mistakes were made by Transocean, which leased the Deepwater Horizon rig to BP, and Halliburton, the company that was responsible for cementing the well to secure it.
It identified eight factors behind the disaster, including mechanical failures, human judgements, engineering design and team interfaces.
The factors included that:
--there were weaknesses in the cement design and testing of the Macondo well;
--BP and Transocean misread the results of a pressure test even though the well was not completely sealed;
--over a 40-minute period, the Transocean rig crew failed to recognise and act on the influx of oil and gas into the well until they were rapidly flowing to the surface;
--even after the explosion and fired had disabled all crew-operated controls, the rig’s blow-out preventer – the stack of valves on the seabed designed to stop gas and oil escaping – “failed to operate, probably because critical components were not working”.
BP also said the decision not to use 21 centralizers to hold the casing centrally in the well bore – a decision that has come under attack by investigators in the US – did “not likely” contribute to the cement’s failure to isolate the main hydrocarbon zones.
Tony Hayward, BP’s outgoing chief executive, said in a statement that “it is evident that a series of complex events, rather than a single mistake or failure” led to the tragedy.
“Multiple parties, including BP, Halliburton and Transocean, were involved,” he said.
The report will be followed by several others, including one by the U.S. Department of Justice, as well as a raft of congressional inquiries and the commission backed by President Barack Obama and Congress.
Avoiding a finding of gross negligence from official inquiries into the accident is an important objective for BP, as that would potentially limit its penalties under the U.S. Clean Water Act to about $5bn rather than a possible $21bn.
BP shares were 1.9 per cent higher at 414½p in afternoon London trading.
(Source: Financial Times)
Photo: The blaze after the explosion on the Deepwater Horizon oil rig.