Oil futures fell for a sixth straight session on Friday, with the U.S. benchmark settling below $60 a barrel for the first time in 2018 to notch its biggest weekly loss in more than a year.
Data released Friday revealed the biggest weekly jump in the number of U.S. oil-drilling rigs since January 2017, contributing to concerns about a surge in U.S. production.
March West Texas Intermediate crude CLH8, -3.43% dropped $1.95, or 3.2%, to settle at $59.20 a barrel on the New York Mercantile Exchange. Prices saw their lowest finish since Dec. 22. For the week, it was down roughly 9.6%, which was the biggest such decline since January 2016.
April Brent crude LCOJ8, -3.24% the global oil benchmark, fell $2.02, or 3.1% to end at $62.79 a barrel on London’s ICE Futures exchange. Brent, which settled at its lowest since Dec. 13, retreated roughly 8.4% this week.
Baker Hughes BHGE, -3.64% on Friday reported that the number of active U.S. rigs drilling for oil jumped by 26 to 791 this week. That marked a third straight week of increases and the largest weekly rise in more than a year.
This offers a “path for much more than a million barrels a day U.S. production increase this year, but prices will need to remain above $50,” said James Williams, energy economist at WTRG Economics. “Not a good Friday for OPEC.”
Until recently, oil prices have been buoyed by production cuts from the Organization of the Petroleum Exporting Countries and other large producers among other threats to supply.
However, OPEC member Iran also plans to raise its oil production in the next four years, according to a report from Reuters.
That has “added to market fears of an increase in global supplies,” said Mihir Kapadia, chief executive officer and founder of Sun Global Investments. “With reports suggesting China could be launching its crude oil futures contract next month, traders could be looking to the Far East to see how such a move could affect global prices.”
Oil-market fundamentals are also changing as recent increases in prices provided incentive for the U.S. to crank up output.
In a monthly report this week, the Energy Information Administration forecast record U.S. crude production of 10.59 million barrels a day this and 11.18 million barrels a day next year. A separate report from the agency also revealed that daily domestic output topped 10 million barrels a day last week—the highest such figure based on EIA records dating back to 1983.
Meanwhile, the downturn in the oil market has come amid a recent selloff in the equity markets, as investors there fret about the potential for higher inflation and central bank action. Stocks in Europe and Asia were on pace on Friday for their worst week in two years after a late slump Thursday pushed the Dow Jones Industrial Average DJIA, +1.38% and S&P 500 SPX, +1.49% into correction territory. U.S. stocks saw volatile Friday, with the Dow was set for a weekly loss of nearly 6%.
In other energy dealings, March gasoline RBH8, -3.66% dropped 3.7% to $1.70 a gallon, with prices suffering a weekly loss of 9.2%, while March heating oil HOH8, -3.66% lost 3.5% to $1.855 a gallon—down about 9.7% on the week.
March natural gas NGH18, -3.41% fell 4.2% to $2.584 per million British thermal units, its lowest finish since late February 2017, for a weekly decline of 9.2%.
—Sara Sjolin contributed to this article