Harry Houdini’s secret (well one of them). Magician / illusionist Harry Houdini frequenly put on events in towns where he would quickly break out of a locked bank vault to the amazement of the crowds. The secret is that bank vaults are designed to keep people out, not to keep people in. All of the defenses are facing outwards. It is apparently trivial to open a bank vault from inside.
I was thinking about that over lunch in relation to this well problem. In the end, my guess is that the well failed for much the same reason. Haliburton put in a cement plug. Its purpose was to prevent the oil and gas under high pressure from going up the well. All the effort and thought was making sure the concrete plug was not pushed up the well casing (remeber that the casing gets narrower as you go deeper). When the methane infiltrated the casing, it exploded in its pressure as the mud was pumped out – that pressure would also have been exerted downward on the cement plug – pushing it away from the bottom of the casing. Once that was breached, then the oil and methane both flowed up the well…
For long time readers, I’m also going to put this whole thing on the “Over reliance on technology” pile, like the Air France plane crash, and the Metro crash in D.C. The people have already testified that when BP’s management pushed forward to withdraw the mud against the advice of the drillers, their attitude was “Well, if it goes wrong, we have the deadman switch that will save us”…. people begin to use the safety devices as a way to operate normally rather than as the last resort.
