Brent crude oil futures were at $60.86 a barrel at 1215 GMT, down $0.23 or 0.38%.
An unexpected rise in US crude inventories offset fears of potential risk to Venezuelan crude supply because of possible sanctions.
"The oil market is partially pricing in the risk to Venezuela's crude production, which has been plummeting in recent years and now languishes just above 1 million barrels per day", Vandana Hari of Vanda Insights said in a note on Friday.
"This would deal a further blow to US refiners that rely on whatever Venezuelan oil is still available and as such would be short-term bullish".
Those deliveries are being made largely through oil-for-debt repayment structures as output from Petróleos de Venezuela, S.A., known as PDVSA, has slumped to near 70-year lows during a nationwide economic crisis. Production of heavy crude in Mexico has been declining, and although there is a strong supply in Canada, there are challenges to getting that crude to the Gulf Coast refineries.
Both Brent and WTI are both backed by light, sweet crudes, and are not directly linked to Venezuelan oil. The leading USA heavy-oil benchmark, Mars, rose US$1.10 to US$60.98 in spot markets on Friday, Bloomberg reported. That mood faltered in recent days as data showed rising production in the US and weaker economic growth around the globe.
Global oil markets are still well supplied, however, thanks in part to surging output in the U.S.
"There's not enough pipes to ship all the oil that companies have been producing", said Jim Burkhard, vice president of oil markets research at IHS Markit. The primary importers of Venezuelan crude are Citgo, Valero Energy, and Chevron.
"The crude market is now focusing on global growth concerns primarily ..." OPEC's latest production cuts tightened the supply of heavy crude from Saudi Arabia.
In the previous week ending January 18, oil prices extended increases.
EIA reported a almost 8M barrel build during last week.
Other industries that rely heavily on oil may feel impacts.
Consumers probably won't feel much pain at the pump.
"It's a function of people keeping an eye on supply concerns out of Venezuela", said Marshall Steeves, energy markets analyst at Informa Economics IG in NY.
"With the US now clearly taking sides with the opposition, changes might be in the making", said Tamas Varga, an analyst at PVM Oil Associates Ltd.in London. One proposal would see Washington declare that any payment to Venezuela in return for oil must go to the new government, or perhaps some form of humanitarian account to help feed the country's starving people.
"Most of the cash that the Venezuelan government gets comes from the USA market, so that means they will have to figure out how to ask the Chinese to get some cash back, because otherwise they will be starved for cash", Monaldi said.