Oil futures lost more ground on after a survey revealed that crude production from members of the Organisation of the Petroleum Exporting Countries has climbed to a almost eight-year high - with output from Canada, Libya and Nigeria all recovering, while a recent slowdown in Iraqi shipments seems to have been ended.
Oil prices have halved from two years ago in a drop that deepened after OPEC refused in late 2014 to cut output to support prices, hoping that cheaper oil would curb higher-cost rival supply such as US shale.
Venezuela acted as a check on the overall level though, as the crisis-hit country's production continues to hit fresh lows, the report said.
"The sharper move up caught everyone by surprise", said a crude futures broker.
Crude stockpiles at Cushing, Oklahoma, the delivery point for WTI and the biggest US oil-storage hub, dropped 166,000 bbl last week, the API said, according to a person familiar with the figures.
Other big Opec Gulf producers, including Kuwait, Saudi Arabia and the United Arab Emirates, also upped production. It also rose by 2.6% YoY (year-over-year). The data come ahead of the weekly USA petroleum data to be released by the Energy Information Administration later on Wednesday.
Refinery crude runs fell by 143,000 barrels per day, EIA data showed.
Members of the Organization of Petroleum Exporting Countries (OPEC) have boosted their output in recent months.
This has principally led to oil prices recovering above Dollars 50 per barrel and settling now in the high USD 45-50 range.
U.S., with near-record gasoline consumption, saw its crude inventories fall by 2.55 million barrels from last week for the eight-straight week of oil drawdowns. The IEA has just revised its forecast for global oil demand growth this year upwards by 100,000 b/d to 1.3 mb/d to reflect the improvement in demand.
It has regained about 80% of the market share it held before nuclear-linked western sanctions were imposed on its oil industry in 2012, Bloomberg News quoted him as saying.
The American Petroleum Institute reported a 2.2 million barrel rise in reserves last week, confounding expectations of a dip at the height of the crucial summer driving season when Americans go on holiday.
Output from OPEC's 14 nations increased by 264,100 barrels a day to 32.858 million a day in June, according to external sources cited by the report.
The agency said that, because global crude inventories are still at "such elevated levels", the crude glut is still acting as a "major dampener" on prices.