The current pact is due to expire in March 2018.
The supply of oil has been hit by unplanned outages combined with scheduled maintenance in Libya - a member of Organisation of Petroleum Exporting Countries, or OPEC. The American Petroleum Institute releases its own weekly inventory report late Tuesday.
Monday's gains came as Hurricane Irma struck the USA southeast with less force than once feared, easing worries that energy demand would be hit hard. Mark Zandi, the chief economist at Moody's Analytics, said the US economy could suffer lost revenue from the storms and the estimate for third-quarter gross domestic product could drop a half point to 2.5 percent as a result. Analysts expect supply to increase as refineries return online after Harvey shut almost a quarter of US capacity. Analysts forecast crude inventories last week rose while products drew down.
Data from the U.S. Energy Information Administration Wednesday showed that domestic crude supplies climbed by 5.9 million barrels for the week ended September 8.
This week's numbers might be incomplete indicators of the longer-term supply and demand outlook, said Mark Watkins, regional investment manager at U.S. Bank.
In a report published Monday, the EIA said that gross inputs to Gulf Coast refineries fell by 34% (3.2 million barrels a day) week over week in the week ending September 1. "That's why you have to look out further". Worldwide benchmark Brent crude LCOc1 dropped by 35 cents to $53.49 per barrel from the previous close.
The news caused oil prices to rise somewhat, with global benchmark Brent crude lifting 0.84 per cent to $54.29 per barrel and US West Texas Intermediate (WTI) rising 0.31 per cent to $48.22 per barrel.
Earlier on Wednesday the International Energy Agency said global oil supplies fell for the first time in four months in August, while also revising its 2017 oil demand estimate up to 1.6 million barrels a day from its July estimate of 1.5 million.
"It is clear that the rebalancing process is under way", he said.
Saudi Arabian Energy Minister Khalid Al-Falih last weekend discussed the potential extension of the deal with his counterparts from Venezuela, Kazakhstan and the United Arab Emirates.