Crude inventories rose 6.5m barrels for the week ended Friday, the Energy Information Administration said today, almost double analysts' expectations of an increase of 3.3m barrels.
Currently, oil prices are rising - global benchmark Brent crude futures are up 1.46 per cent at $56.39 per barrel, while West Texas Intermediate crude is trading up 1.23 per cent at $53.46.
The US data shows an oversupply of crude could drag on despite the Organisation of the Petroleum Exporting Countries (Opec)'s best efforts to cut production.
So far, according to a Reuters survey, members have delivered on about 82 per cent of their deal to cut 1.8m barrels per day (bpd) by lowering production in January by 1.16m bpd.
"Over the past two weeks, Department of Energy inventories have risen by 9.3m barrels, raising the question as to the wisdom of Opec producers cutting back on production at a time when US shale producers are pushing rig count numbers back to 2015 levels," said Michael Hewson, chief market analyst at CMC Markets.