I've only recently gotten into the operations side of the business, so I'm by no means an authority on the matter, but I can tell you that we routinely deal in formation pressures in excess of 10,000 psi after you account for hydrostatic pressure from depth. That is, you've got static pressure from the fluid column, but the formation is actually at a higher pressure than that. That's why we use heavy weight drilling muds, to try and make the fluid column heavy enough to balance the pressure in the formation. (Sounds like mistake #1 to me.)
I haven't been able to get many details on this yet, but I bet we'll be getting a LOT of safety lectures about this in my group in the next couple weeks. This is an environmental catastrophe, but there's no way in hell it was unavoidable. The entire point of a gas well is you WANT to hit a pocket of gas. What is making this so bad isn't so much that the gas was under a lot of pressure. It's always under a lot of pressure. We have tool designs older than I am that are fully capable of dealing with that. The problem is the shear volume of gas in that formation and that they let it get out of control in the first place. Everything I'm hearing is pointing to a combination of shoddy tools and poor adherance to standard operating procedures.
Maybe I'm wrong. Maybe the locals are just looking to pin this on someone, but I rather doubt it. The fact that the companies involved are being so tight-lipped as to what happened at the rig itself doesn't do loads for their credibility.
The fact that it has hardly even slowed down is truly awe-inspiring. The gas gets in the mud and reduces its density so the whole mess rushes uphole. At the rate it is going, the borehole must be absolutely huge by now. I don't know what we can do to stop it.