So here is where we are – using the original BOP, the well has been plugged from the top. It’s important to understand there are two issues – the interior of the casing, and the area around the outside of the casing between the steel and the rock (the annulus).
The Cement Plug only is plugging the interior at the top of the casing. Below the plug there is still oil and gas under pressure. BP (at the direction of their government overlords) is now testing to make sure it is safe to remove the original broken BOP. They remove the pressure, drain out any remaining oil and make sure no pressure is still coming through. If that’s clean, they will remove the broken BOP and take it off for analysis to figure out what happened in the first place. Just as a precaution, a new BOP will be put on top (but with no drill string inside)
The relief well is now in position that it can break into the annulus (the area between the well casing and the rock) and see what they find. They might find oil and gas under pressure, which would mean the original cement job did not seal the well or the casing has a leak (I doubt that) or they’ll find an empty space with nothing inside. Either way, they’ll probably pump in cememt to be REALLY sure the annulus is sealed with cement. Once that is done, then it’s decision time again – you have a 13,000 foot long pipe most of which is still filled with oil and gas under pressure, with a concrete cork at the top. You can penetrate the casing (which now puts full pressure into the relief well and risk a second blowout, although at reduced pressure and a lot less likely to be a “surprise”…. or you can drill down all the way to the bottom of the casing and pump concrete like crazy and try to plug the bottom. Since the well itself is top killed, you can’t use upward movement of the oil and gass to draw the cement into the inside of the bottom of the casing. That’s kind of where the decision making is stuck right now.
Probably if this was not as bad as it is, after replacing the BOP with a reliable one, they would just drill back through the top kill and either make it a producing well, or then use the bottom kill allowing the concrete to flow upward. Perhaps it will be a circuit – punch a hole in the casing and then pump in the mud and cement from the bottom. Probably a lot depends on how porous the area is right below the bottom of the casing – it may be impossible to “fill” the area with cement, although they have tricks up their sleeves like cement that will only harden when it encounters oil
I oversimplified that. There is another wrinkle – inside the casing you still have the drill string, a tube within a tube. The drill string itself is capable of delivering gas and oil under pressure if it wasn’t sealed. The top of the drill string is caught in the closed BOP shear ram. You can’t pull off the BOP until you solve that. The drill string is now encased in cement, so it isn’t going anywhere any time soon.
The Enterprise ROV2 camera is focused on what appears to be a new “cap” of some sort.
Someone should tell President The Obama that the straw is in place and awaits his sanctified lips. If he sucks half as much as I think he does, problem solved.