A four-month low on Thursday, caused by concerns about global demand, sent oil prices plummeting to a four-week low on Friday, marking their fourth consecutive week of losses.

Brent crude futures advanced by 0.1%, to $77.49 per barrel meanwhile U.S. West Texas Intermediate crude added 0.1% to $72.960 per barrel. Over the past four weeks, both have experienced a value loss of about 6%.

For both futures, prompt monthly spreads have switched to contango, a market tendency in which prompt prices are less than those in subsequent months, indicating a solid supply.

This week's sharp increase in U.S. crude stocks and production, which have remained at record highs, are mostly to blame for the oil market's slump. Analysts say this has raised concerns about poor demand in the world's top oil consumer despite high output.

According to ING, a rollover of further Saudi supply cuts into early 2024 should help eliminate the anticipated excess and offer some market support.