Repsol said it made the discoveries in the Western Siberian oil field, Ouriyinskoye. Discoveries from wells Gabi-1 and Gabi-3 are estimated by Russian authorities to hold a combined 240 million barrels of oil equivalent.
The Russian Ministry of Natural Reserves says this is the largest find made in Russia in the last two years, the company said in a statement Monday.
"The use of modern seismic techniques to detect these potential resources has allowed Repsol to make these significant finds in a relatively unexplored area of West Siberia," it said.
The Kremlin last week said it expected major investments in oil operations in the eastern part of Russia will boost export potential by 2035.
Russia is one of the world's leading oil producers, producing more than 10 million barrels of oil per day on average. Most of the country's oil fields are in the western region of Siberia.