The world will store unwanted oil for most of 2016 as declines in U.S. output take time and OPEC is unlikely to cut a deal with other producers to reduce ballooning output, the International Energy Agency said. The agency, which coordinates energy policies of industrialised countries, said that while it did not believe oil prices could follow some of the most extreme forecasts and fall to as low as $10 per barrel, it was equally hard to see how they could rise significantly from current levels.