EIA expects a rise of 117,000 barrels in September U.S. shale oil output.
Official Energy Information Administration (EIA) data will be published late on Wednesday.
Oil prices fell on news that refinery runs in China dropped in July.
Traders await the latest USA oil inventories data for clues about domestic production and consumption.
Brent and US crude reached two-month highs in early August but have slid over the last few days, dropping more than 2.5 percent on Monday.
Analysts polled by S&P Global Platts expect the EIA report to show that crude supplies fell 3.6 million barrels for the week ended August 11.
That compared with analyst expectations for a decrease of 3.1-million barrels. West Texas Intermediate, the USA benchmark for the price of oil, was down 0.55 percent to $47.33 per barrel. "This results in a tug of war that we have witnessed all year and the final outcome is a range-bound market", said Matt Stanley, a commodities broker at Freight Investor Services in Dubai reports CNBC.
Oil Rises Ahead of Expected US Inventory Draw
Concerns over growing US shale-oil production weighed on the market, but prices found some support from the latest forecasts calling for a decline in weekly USA crude supplies. Phil Flynn, senior market analyst for the PRICE Futures Group in Chicago, said in a daily emailed newsletter the leveling effect may be overstated because production growth isn't keeping up with demand.
"Excessive supply.is continuing to weigh on oil prices".
Crude oil prices suffered a dual blow Monday from steady, though at times shaky, production recovery in Libya and from a report of an expected increase in US shale oil activity.
Libyan production has surged in the past year, surpassing 1 million bpd at the end of June for the first time since 2013, but output remains vulnerable to local protests.
Ed Morse, global head of commodities research at Citigroup, told Bloomberg, "The OPEC position even with Russian Federation is really not sustainable overt a long period of time, they're losing revenue by doing what they've done", and the US producers "can survive at a lower price".
The Organization of the Petroleum Exporting Countries together with non-OPEC producers like Russian Federation has pledged to restrict output by 1.8 bpd between January this year and March 2018.
On the demand side, analysts see a gradual slowdown in fuel consumption growth.
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