Oil prices fell nearly 2 percent Thursday, after U.S. data showed a surge in crude inventories last week, partly due to continued production cuts at refineries in the Gulf of Mexico following Hurricane Laura.
Brent crude futures fell 73 cents, or 1.8 percent, to $40.06 a barrel, while U.S. West Texas Intermediate fell 75 cents, or 2 percent, to close at $37.30 a barrel.
U.S. Energy Information Administration said crude inventories rose 2 million barrels last week.
This confirmed the upside that had been predicted by an increase of three million barrels in the American Petroleum Institute report, but it was in contrast to a decline of 1.3 million barrels that analysts had expected in a Reuters poll.
Jim Ritterbusch, president of Ritterbusch & Co. in Galena, Illinois, said, "Today's crude data appears supportive of falling prices ... The only opposite element is that the 2 million (barrel) increase is less than the Petroleum Institute report."
And he indicated that prices may continue to decline unless refiners in the Gulf of Mexico return to work at full capacity soon after being shut down by Hurricane Laura.