International benchmark Brent crude fell slightly to $66.97 at 1400 GMT on Friday, while American benchmark West Texas Intermediate (WTI) saw prices of $59.24.
Brent crude traded $67.22 at 0639 GMT on Monday, and WTI registered as $58.52 at the same time.
On Thursday, oil prices fell nearly 1 percent from the previous day's peak of 2019, supported by tightening of global stocks.
OPEC production cuts and U.S. sanctions on key producers Venezuela and Iran also affected prices during the day.
According to Baker Hughes data, last week U.S. energy firms reduced the number of oil rigs operating for a fourth consecutive week with drilling slowing to its lowest in nearly a year.
Furthermore, Iranian oil shipments slumped this week as part of the U.S.' strategy to cut Iran’s oil exports by around 20 percent to below 1 million barrels per day from May by requiring importing countries to reduce purchases to avoid U.S. sanctions.
By Muhsin Baris Tiryakioglu
Anadolu Agency
energy@aa.com.tr