Oil prices slumped 3% on Monday.
Surging cases of the Omicron coronavirus variant raised fears new curbs may hit fuel demand.
Commercial oil stocks in the United States last week decreased by 4.5 million barrels.
Oil prices fell for a third day straight on Wednesday on growing expectations that supply growth will outpace demand growth next year.
Governments around the world, including most recently Britain and Norway, have tightened restrictions to stop the spread of the Omicron variant.
Both benchmarks posted gains of about 8% last week.
Kosatka.Media has compared the volume of fossil fuels reserves with well-known Ukrainian reservoirs.