Many companies were in the hunt for the Russian Arctic oil, including BP PLC (NYSE ADR: BP), Royal Dutch Shell PLC (NYSE ADR: RDS.A), Chevron Corp. (NYSE: CVX), Total SA (NYSE ADR: TOT) and Statoil ASA (NYSE ADR: STO), but it was Exxon that walked away with the prize.
The arrangement with state-controlled Rosneft (PINK: RNFTF) gives Exxon a significant advantage over its major rivals -- all of which have struggled in recent years to replace the oil they're extracting with new sources.
Rosneft, in which the Russian government has a 75% stake, estimates the three Kara Sea blocks where Exxon will be exploring contain about 36 billion barrels of recoverable oil.
"If that figure is correct and Exxon is able to produce the fields, we are talking about one of the world's largest oil discoveries in the last 50 years," Fadel Gheit, an energy analyst at Oppenheimer & Co., told MarketWatch. "But it remains to be seen how much of that oil is economically recoverable."
Rosneft estimates total reserves in the area at about 110 billion barrels of oil equivalent - an amount four times the size of Exxon's proven global reserves.
Quid Pro QuoHaving access to reserves of that size will help Exxon rectify its replacement ratio for oil. Earlier this year Exxon reported that for every 100 barrels of oil it produced, it found just 95 barrels of new oil.
Exxon has been more successful in replacing natural gas resources - it finds 158 cubic feet of gas for every 100 it extracts. But with natural gas prices slumping, the company would much rather find more oil.