It's pretty much gone now, just the last dregs to wring out.  The oil boom days are over.  God knows where the money's gone though - Norway's used its oil money to build up a wealth fund of US$878 billion, while we have a national debt of £1.8 TRILLION, which is utterly disgusting for a formerly oil-rich country.

Once it's all gone we'll find that we're all pretty much broke - England included.  This money and borrowing more recently has allowed the govt to spend stupid amounts while not taxing enough to cover it.  Nobody wants spending cuts but nobody wants to pay more tax either, so that's why we've got no savings and massive debts.  Politicians of all parties have used oil money and debt to achieve the seemingly impossible.