Both oil benchmarks showed relative gains during the week ending August 13, although concerns over future demand and the global increase in COVID-19 cases kept price rises limited.
Brent crude traded at $71.13 at 1248 GMT on Friday, posting a 1.23% gain from Monday when the benchmark began to trade at $70.26 per barrel.
American benchmark West Texas Intermediate (WTI) traded at $68.89 at the same time on Friday, indicating a rise of around 1.48% relative to $67.88 a barrel early Monday.
On Friday, however, Brent slumped by 0.25% compared to Thursday's closing at $71.31, and WTI also dropped by 0.29% compared to Thursday's closing at $69.09.
The spread of the COVID-19 Delta variant is instilling fears of lower demand and continuing to suppress oil prices, particularly with the spread of the Delta across 100 countries so far, resulting in new restrictions in Asia.
Oil prices also dropped after the International Energy Agency in its monthly report on Thursday revised its estimates to reflect lower global oil demand for the remainder of 2021 and for 2022.
By Zeynep Beyza Kilic