One trader said up to four cargoes with Saharan left the region. Venezuela has said it is looking to increase imports of light grades including from Algeria to blend with its heavy crude grades to optimise refining operations.
US refiner Valero was also believed to have brought some Saharan into its US Gulf refinery.
One trader said he estimated Saharan has strengthened to around parity with Dated Brent from as low as minus $1 per barrel previously. Azeri has also strengthened but values were difficult to establish yet, a trader said.
In the Platts window, Russia's main export grade Urals weakened further in the Mediterranean but held steady in northwest Europe, with oversupply keeping many buyers on the sidelines despite stronger refining margins.
ENI offered a Urals cargo in the Baltic at dated Brent minus $1.70 a barrel, some 20 cents above offers in the previous session, but found no buyers, traders said. Unipec bid for a cargo at dated Brent minus $1.95, some 5 cents stronger than bids earlier in the week.
In the Mediterranean, ENI offered an 80,000-tonne cargo at dated Brent minus $1.75 a barrel, some 40 cents weaker than a deal on Thursday but found no buyers.
Refining margins for Urals were at their best for several months because of a decline in Brent prices to a two-year low, with simple plants standing to make over $5 a barrel, according to Reuters models.
The United States announced more sanctions against Russia on Friday, affecting oil and defence industries and further limiting the access of major Russian banks to US debt and equity markets.
Any further Western sanctions which may aim at technology for Russia's modernising oil refineries could lead to gasoline shortages, an energy ministry official said.
Russian state-owned oil firm Zarubezhneft plans to sell 300,000 tonnes of Urals crude blend, offering the first cargoes for export from a local exchange.
A trader said that activity from the Ras Lanuf oil terminal in Libya after around a month of no vessels departing indicated that exports would likely soon increase further.
Tanker Aegean Pride left Ras Lanuf on Sept 11 with destination Genoa in Italy. Tracking showed the Aframax tanker draft loading was 85 percent full and last seen positioned off the coast of Sicily.