For pity's sake, how often do you have to be told this simple truth, TTT? Nobody ever claimed Scotland "owns the North Sea". On the other hand, IF the Scots had voted for independence at the 2014 referendum, they WOULD have acquired ownership of part of it, just as England would and just as Norway, Denmark, Holland, Belgium and Germany already DO own parts of it! In other words, a dividing line separating the Scottish and English areas would of necessity have been internationally agreed.
The big difference, as England would have discovered, is that the (southern) English bit would be the one where oil/gas resources are dying out, whereas the (northern) Scottish part...ie the North Atlantic as well as the northern North Sea...still has ample recoverable resources. These will one day be brought into use, barring some currently unknown energy source being discovered to drive the world's transport needs!
A separate England would have had no share of these whatsoever and I have always been convinced that is why Westminster did everything it could to stymie the independence referendum.