Saudis face another test after battle with shale is won

London

EVEN if Saudi Arabia wins its struggle with US shale producers over market share, it will face a new billion-barrel adversary.

It won't be regional nemesis Iran, a resurgent Iraq or long-standing competitor Russia. The answer will be more prosaic: Even when overproduction ends, a stockpile surplus of more than one billion barrels built up since 2014 will remain, weighing on prices.

Inventories will keep accumulating until the end of 2017, the International Energy Agency forecasts, and clearing the glut could take years.

"We may get to the end of the year, and even though supply and demand are in balance, the market shrugs and says 'So what?' because it's waitin…