A poll of six analysts, taken ahead of weekly inventory reports from industry group the American Petroleum Institute (API) and the U.S. Department of Energy’s Energy Information Administration (EIA), showed a crude stock build of 5 million barrels on average last week.

The U.S. shale oil industry may have forever abandoned its heavy-spending ways in the face of sliding crude prices, Schlumberger, the world’s No.1 oilfield services provider, said.

Read MoreThe price of oil is going lower: Trader

Spending cuts already announced by producers – to the tune of 25 to 60 percent – have dropped the rig count by 45 percent since late 2014, and output will soon decline or flatten out so prices can recover, said Schlumberger Chief Executive Paal Kibsgaard.

The dollar fell further on Monday on views a Federal Reserve interest rate hike will come later rather than sooner.

U.S. stocks gave up gains and closed slightly lower.