International benchmark Brent crude decreased to $63.31 while American benchmark West Texas Intermediate (WTI) saw prices at $57.33 at 10.55 GMT on Friday.
On Monday, Dec. 11, Brent crude traded at $63.20 while the cost of American benchmark WTI was $57.20 at 06.09 GMT on Monday.
On Tuesday Dec. 12, Brent crude jumped to $65.83 per barrel, the highest in 2017, after the shutdown of a major North Sea pipeline. The oil prices increase came after the Forties North Sea pipeline, which delivers 450,000 barrels of oil per day, shut down for repairs.
Data from the International Energy Agency’s (IEA), Energy Information Administration (EIA), and Organization of the Petroleum Exporting Countries (OPEC) reflected fluctuations during the week.
Global oil supply increased by 200 thousand barrels per day in November to 97.8 million barrels per day (mb/d) compared to the previous month, according to the IEA's Thursday report.
OPEC's crude supply fell in November for the fourth consecutive month to 32.36 mb/d, down 1.3 mb/d on a year ago.
In addition, crude oil production in the U.S. increased for the eighth consecutive week, according to data from the EIA on Wednesday.
The U.S.' crude output rose by 73,000 barrels per day (bpd) to reach a little over 9.78 mb/d for the week ending Dec. 8, the EIA data showed.
According to OPEC's data on Wednesday, OPEC's crude oil share of total global production dropped to 33.3 percent in November. The cartel's crude oil production decreased by 133 thousand bpd to 32.45 mb/d in November.
Also in November, output in non-OPEC countries rose to 57.82 mb/d, an increase of 810 thousand b/d from October.
By Gulsen Cagatay
Anadolu Agency
energy@aa.com.tr