Global oil inventories have risen to a record level just shy of 3bn barrels, the world’s leading energy agency said on Friday, even as the collapse in prices has boosted demand to a five-year high.“This massive cushion has inflated even as the global oil market adjusts to $50/bbl oil,” said the International Energy Agency (IEA) in its closely watched monthly oil market report. The wealthy nations’ energy watchdog said inventories in industrial nations broke records and increased by 13.8m barrels to 2.98bn, according to the latest data for September. They surpassed seasonal trends, more than 257m barrels above average levels. The overhang in oil production that developed in the US as North American output surged has spread across Europe and Asia and is not just restricted to crude but also includes refined fuels.