Has US shale usurped Opec as global swing producer?

IT'S happy days for Opec, but once the whoops and hollers die down, the group should take a long hard look at itself. Because it's lost its crown as the world's top oil player.

Shale billionaire Harold Hamm told Bloomberg TV on Friday that forecasts of US oil production growth are way too optimistic and are distorting global crude prices. That news was greeted with big smiles - if not wild cheering - by oil ministers meeting in Vienna to discuss the effectiveness of their output deal. But it is too early for them to start celebrating just yet.

That wasn't the only boost ministers got ahead of their latest gathering. Analysts at Goldman Sachs Group said in a Sept 21 note that the level of Brent backwardation - the premium for crude for delivery next month over that for …