Anyone know at what approximate PSI the oil is being spewed into the ocean? Would it be doing so “at pressure” or more or less oozing out?
There is some discussion about that on The Oil Drum. Check this thread. I haven’t read it all the way through, it may be in a different place.
Start reading at the post made May 2, 2010 - 9:03am. They’re talking about the pressures they would expect to see being around 8,500 psi; but one of the rig survivors is saying they were working with 30,000 to 40,000.
Either way, the answer to the OP is “at pressure”. Serious pressure. A water jet at those kind of pressures can cut through metal.
Yes, but the discussion goes into such delicious detail. I would hate for SanDiegoTim to miss out on it. 
The 30-40,000 psi is the downhole pressure. 8,500 psi was the pressure measured at the sea bed when the hole was filled with drilling fluid.
Assuming the well is 100% oil, my calculations give me around 25,000 psi at the well head, directly below the BOP. Purely going on press releases, it looks like the BOP is still partially working (impressive as it’s only rated to 15,000 psi), so it’s providing some protection.
Short answer: Anywhere from 1psi to 25,000psi. My totally WAG is around 5,000 psi.
If you haven’t seen it already, this is the sole picture they’ve released of the leak. BP have refused to release the footage of it. It’s pretty terrifying when you think how quickly that column of oil is thundering out of the pipe, and that it’s been doing so for weeks now.