BUT, so much oil has come out....are you saying that the GAS will take it’s place?? huh??
No, only as much as is continually produced.
The Earth is continually making oil, but it does not appear to be making methane, or at least not as fast as it is making oil.
When the well stops flowing, it can be left to recover for a while, then it can be pumped (from another bore, this one is unworkable)
The gas is continually expanding....there is so much of it that is condensed under the extreme pressure....as the oil leaves, more of the gas changes phase and expands, or leaves. Also, there is so much oil down there under that extreme pressure, that it will take a great deal of time for enough of the oil to leave the reservoir and drop the pressure.
Once the pressure in the reservoir bleeds down and equalizes with sea pressure on the sea floor, the flow of oil will stop.