Venezuela may be forced to start shutting in oil production as it runs out of storage space amid the U.S. tanker blockade, Bloomberg has reported, citing unnamed sources. According to the sources, the biggest oil storage hub and tankers at Venezuelan ports could fill up within 10 days, prompting production curbs. Earlier this week, Reuters reported that some 11 million barrels of Venezuelan crude were stuck at sea amid the U.S. escalation, prompting deeper discounts and demands from buyers for changes in the spot contracts, under which the oil…