Joel Achenbach and Monica Hatcher, two reporters pose questions to Thad Allen. They are very important as far as getting Thad Allen to put on record that he thinks there is no chance of a further blowout and that the cement seal has worked.
Joel Achenbach: Yes Admiral just to get back to something you said a little earlier about there could be stagnate oil in the annulus there and you mentioned something about pushing that, raising the pressure and pushing that up into the blow out preventer.
Can you just clarify that I guess what I'm wondering is there a concern that the going in there you know intercepting the annulus and going in with more cement or mud could somehow back fire I guess and cause a problem?
Thad Allen: Yes good question (Joel), let me I'm not an oil field engineer although I've been to school pretty good in the last 100 days and let me see if I can explain this in terms of that I understand it maybe it'll be useful to you.
The casing in which the drill bit and the well and the well pipe sits (hang) from the top of the well head. And then they kind of telescoped down to the smaller diameters. In that mechanism where they hang off the top of the well head, there was a seal and if enough pressure is applied from the annulus, this is outside the casing, on that seal it is meant to give way so it won't cause damage to the well bore.
In other words it's like a relief valve, and the seal which completely circles the casing at the top of the well if enough pressure is exerted will rise up and allow oil to flow. One of the theories was that somehow sometime during the explosion or what happened that that pipe was lifted up to allow that seal to be opened. It might have allowed oil to move up into the blow out preventer, it might have been the source of the hydrocarbons coming up other than the actual casing itself.
We don't think that's the case right now we think it's seated where it should be but what we wouldn't want to have happen is to start pumping mud and cement into the annulus at the bottom is filled with cement and you have stagnate oil there. And we increase the pressure as we're doing that so that stagnate oil is forced up and that forces that seal to rise up open itself and go into the blow out preventer.
And as you know we restricted the pressure on the injectivity tests in the top kill to be less than 8,000 psi. The cap itself is rated at 10,000 psi and what we want to understand is we go ahead with the mud and the cement for the bottom kill is there any chance at all that that would force stagnate oil up to the point where it would lift that up again, open those seals, push that up into the blow out preventer and the capping stack and at some point erode, approach pressures that might be a concern to us.
We think it's a very low probability outcome but the discussion of those seals and whether or not that pipe has ever been lifted is something that's been discussed for some period of time. But we think we just need to rule it out before we go forward.
Joel Achenbach: Can I just ask that, is that if that did happen the well would still have the cement plug at the bottom so you wouldn't return to a free flowing gusher with full communication between the reservoir and the Gulf, would you?
Thad Allen: Absolutely correct. There is very little harm to the environment but we need to understand that they would like to have the blow out preventer if they can removed intact.
Monica Hatcher: Yes and the annulus I was just trying to get an idea?
Thad Allen: Yes I'm sorry.
Monica Hatcher:How big that space is.
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