Russia has been heavily relying on India and China as main buyers of its crude after European embargo and price cap policies were imposed in December last year after Russia's action in Ukraine that Moscow calls a special military operation.
Brazil is part of the BRICs alliance together with India and China which have been the most active buyers of Russian oil heavily discounted because of sanctions.
Unlike India and China, Brazil is a major oil producer and exporter, but it does occasionally import crude for domestic refining needs.
Russia's Lukoil is shipping 80,000 metric tons of its Varandey crude oil on the Stratos Aurora vessel from Murmansk port to the terminal of Madre de Deus port in Brazil, operated by Transpetro, a subsidiary of Petrobras, according to sources and shipping data.
Varandey Blend is a light sweet crude oil grade, as other Russian oil grades have mostly been shipped to India and China in recent months.
Lukoil, Petrobras and Brazil's Ministry of mines and energy did not immediately respond to requests from Reuters for comment.
Information on the buyer of the cargo was not available.