The independent Centre For Research on Energy and Clean Air (CREA), oil revenues have been falling since March.
Despite many countries refusing Russian energy supplies, her revenues from energy is still high. Among these countries are the US, UK and EU.
Overall, energy sales has also declined from a peak of well over $1bn a day in March.
However, CREA report claimed that Russia still earned $97bn in revenue from 24 February to 3 June.
The EU plans to reduce gas imports from Russia by two-thirds within a year and ban Russian oil imports arriving by sea by the end of 2022.