Geneva-based Petro-Logistics said on its website that Iranian crude and condensate exports in December "fell steeply" from November to less than 1 million barrels per day (bpd) due to USA sanctions - lower than some other estimates.
US crude inventories sharply rose by 8 million barrels last week, the Energy Information Administration said, versus forecasts of a decline of 42,000 barrels. Venezuela's crude is so heavy it must be blended with naphtha, a liquid hydrocarbon mixture used to dilute oil so that it can be transported.
Oil prices rose by 1 percent on Friday as turmoil in Venezuela triggered concerns that its oil exports could soon be disrupted, Trend reports citing Reuters.
"The chances for another down-day are not bad at all if you believe the confirmation of last night's (U.S. inventory) stats by the EIA this afternoon will actually put further downward pressure on prices". The global benchmark crude has dropped 1.9 percent so far this week.
Though the United States produces almost 12 million barrels of oil a day, complex Gulf Coast refineries need heavier crude grades to produce diesel and other high-margin products, and can not simply sub in light crude.
"It's really the first quarter that's the big concern among investors right now", Matthew Blair, an analyst at Tudor Pickering Holt & Co., said Thursday in a phone interview.
Venezuela is very reliant on the USA for its oil revenue.
Stop-gap measure brings temporary end to government shutdown — IN Focus
However, Scalise said the president could deliver the State of the Union early next week, and that it should be done in the House. Some Republicans, however, cautioned against forcing another government shutdown over the border wall.
The oil executive also underscored "difficult access to water, and electricity" in Venezuela. That gentle approach left the oil market oversupplied, helping to send prices tumbling.
But supply is tighter for heavy crude oil, which is what the US imports from Venezuela.
Maduro responded by breaking relations with the United States. Francisco Monaldi, fellow in Latin American energy policy at Rice University's Baker Institute, noted that in the event of oil sanctions, the USA would also have to import oil from Organisation of the Petroleum Exporting Countries (OPEC) that are tightening their supply. Those sanctions faced opposition from Republican lawmakers representing Gulf Coast states, where refineries process heavy crude into fuels.
U.S. crude oil refinery inputs decreased during the week ending January 18, the U.S. Energy Information Administration (EIA) said on Thursday.
The biggest U.S. importers of Venezuelan crude past year were Citgo, Valero and Chevron, according to Rystad Energy. That's because light oil yields more gasoline than diesel, so as fuel producers seek to ramp up diesel production, they are piling up on excess gasoline.
Other industries that rely heavily on oil may feel impacts.
The No Oil Producing and Exporting Cartels Act, or NOPEC, is a congressional bill that seeks to apply US antitrust laws to OPEC to prevent the group from coordinating production to influence oil prices. Even if Maduro's government is replaced, "the road back for Venezuela will be extremely arduous given the depths of the economic and humanitarian crisis", Tran and fellow RBC analyst Helima Croft wrote in a note.