Oil prices dropped on the results of the Organization of Petroleum-Exporting Countries' (OPEC) meeting. The meeting ended without any agreement to cut oil output on Friday. OPEC President Emmanuel Ibe Kachikwu, Nigeria's Minister of State for Petroleum Resources, said on Friday that the OPEC decided to keep its output limit unchanged and to monitor closely market developments in the coming months.

OPEC Secretary-General Abdalla El-Badri said on Friday that the OPEC postponed its decision until the next OPEC meeting, which is scheduled to be on June 02, 2016.

OPEC's oil output is about 31.5 million barrels a day.

Market participants also eyed the rig count data. Oil driller Baker Hughes said on Monday that the international rig count for November 2015 fell to 1,109 from 1,111 in October 2015.

The average U.S. rig number for November 2015 declined to 760 from the 791 in October 2015.

The worldwide rig count for November 2015 decreased to 2,047 from the 2,086 in October 2015.

WTI crude oil for January delivery fell to $37.91 a barrel on the New York Mercantile Exchange.

Brent crude oil for January declined to $41.46 a barrel on ICE Futures Europe.