Oil prices declined on concerns over the global oil oversupply. The Organization of the Petroleum Exporting Countries (OPEC) released its monthly report on Monday. OPEC said that its oil production was 31.54 million barrels a day of crude in August, higher than in July. The target is 30 million barrels a day.

OPEC expects the oil demand for its crude to be average 30.31 million barrels per day (bpd) next year, up 190,000 bpd from last month.

OPEC expects that non-OPEC members will rise their output by 160,000 bpd next year, down 110,000 bpd from last month, while U.S. shale oil production was downgraded by 100,000 bpd.

Global oil demand growth is expected to be 1.29 million bpd in 2016, down 50,000 bpd from last month.

The oil driller Baker Hughes reported on Friday that the number of active U.S. rigs declined by 10 rigs to 652 last week. It was the second consecutive decrease.

Combined oil and gas rigs fell by 16 to 848.

Earlier last week, Baker Hughes said that the average total rig count declined by 17 to 883 in August from July.

WTI crude oil for October delivery fell to $43.81 a barrel on the New York Mercantile Exchange.

Brent crude oil for October declined to $47.13 a barrel on ICE Futures Europe.