Blowout Preventer

[tigertoy]

Several weeks ago, just as we were learning that a major oil spill was happening in the Gulf, I distinctly recall hearing a news story that explained that the reason that the now infamous blowout preventer failed to work was that it was built with two redundant control systems, but one of them had been disconnected and they let the batteries go dead in the other.  In more recent weeks, we've heard lots of finger pointing and grandstanding and promises to get to the bottom of what happened, but I haven't heard any repeat mention of the specific, extreme negligence described in the earlier report.  Was I hallucinating?  Was that report discredited, or was it quietly forgotten because it's in some people's interest to have a big ongoing controversy about what went wrong?

Comments

[catsittingstill.livejournal.com]

I can't help here--I don't recall hearing this about the blowout preventer.

[shockwave77598.livejournal.com]

I'm aware that one system died, and that the other system failed to function when commanded. The biggest problem is that during a test, someone screwed up and destroyed the seals inside the BOP. Chunks as big as you hand came up in the mud. But replacing the BOP requires you pull up ALL the pipe you've put down, change it out, and then put the pipe back before you can continue. BP decided to be cheap since the platform costs 1Million bucks a day to operate.

Then BP did the extreme dumb stunt of taking out the drilling mud before the cementing was finished. See, the weight of the mud keeps the oil and gas from escaping. Take it out, and nothing stops it from entering your pipe.

And you know how a percolator works, right? The steam bubbles expanding as they rise through a tube, filling the tube and pushing liquid ahead of them? Same thing happens to oil and natural gas. The methane bubbles are tiny at 90 atmospheres, but become enormous by the time they reach 1 atm. So if nothing balances the pressures in the tube, the bubbles enter and drive oil out at incredible pressures as the expanding bubbles rise.