Excellent thread Op, thanks for clearing this up.
I guess to sum it all up in a short form.
You pump a thicker goo down the pipe to stop the flow of the thinner goo.
However, as things are not sealed, the thicker goo is also flowing out the top, while you are trying to push the thinner goo back down the pipe.
If you don't pump the thick goo fast enough, the thinner goo will push it back out of the top of the pipe and the leak won't be stopped.
If you push it too fast, then it will create too much pressure, and make the leak worse way down below where the real problem lies.
So if I figured this correctly, at 1,800 Meter depth or around 5,000 - 6,000 ft, water pressure is around 1820 dbar or 2,639 PSI. If well pressure is
20,000 psi, then that is a considerable differential.
When you look at the deepest part of the ocean, the deep trenches, they are deeper than the well itself, which from what I am reading is 23,000 ft,
while the Mariana Trench is 35,000 ft. Yet ocean pressure at 35,000 is at 16,000 psi, or 8 tons per square inch. You are saying that the oil
pressure from this well is even higher than that.
I don't see how concrete is all that effective of a material under those conditions.