[QUOTE=caledonia;32637]this has appeared on the BBC:
“
US House of Representatives investigators say they have uncovered significant problems with one of the well’s crucial safety devices, its blowout preventer (BOP), which may have contributed to the explosion.
The BOP, built by Cameron International, had a leak in its hydraulic system and lacked the power to cut through joints to seal the drill pipe, Representative Henry Waxman told a hearing on the spill.
Just hours before the explosion, the well failed a negative pressure test, he said, citing BP documents received by the Energy and Commerce Committee.
The hearing was also told that the BOP had been modified, which made it difficult to operate after the accident, and its emergency back-up controls may have failed because the explosion that destroyed the rig also disabled communications preventing workers from sending signals underwater.
On Tuesday, BP and other oil industry executives traded blame in Congress.”
any word on the state of the BOP and what the “modifications” were?[/QUOTE]
Caledonia, I have (unsurprisingly) read nothing about what modifications were allegedly made to the DWH stack, but I can tell you first-hand that before running that stack there was an exhaustive sequence of function and leak tests that needed to be performed. Every component of the BOP stack is pressure tested to its rated capacity (15000 psi in this case) and every component is function tested numerous times to make sure that it does what it is designed to do. All of these tests would have required a sign-off from the BP representative (Company Man) on board, and more than likely an independent inspector such as DNV, MMS etc.
In addition to these pre-deployment checks, there is a further requirement to function-test the BOP every 14 days after it has been run subsea. Again, everything has to work and everything has to be signed off.
To put this into a more human perspective, the job of a Subsea Engineer is to ensure that every component of the stack is working as it is designed to. You simply don’t run or operate a stack that’s not working properly, because at best (in 5000 ft) you’re looking at 3-5 days of non-stop work to retrieve, repair and re-run the BOP. At worst, it will kill you.
If, as you quote, there was a hydraulic leak sufficient to compromise the operation of the shear rams then that stack should/would have been pulled to surface immediately. And even if it wasn’t, the well was cased and cemented. The BOP should not have been the last line of defence against a well kick. To me (and this is just my personal take), it sounds like BP are so desperate to cover up bad decisions that they made while abandoning the well that they are attempting to blame anybody but themselves.