China Petrochemical Corp., known as Sinopec Group, said Monday that it would gain 100 million barrels of "recoverable resources" from the purchase of French major Total SA's (FB.FR) stake in a Nigerian offshore oil project.

A Sinopec subsidiary, Sinopec International Petroleum Exploration & Production Corp., or SIPC, paid $2.46 billion for Total's 20% stake and operating rights in offshore block OML 138, which is located in the Usan field in the Niger Delta basin, it said in a statement.

Recoverable resources refers to the total oil and gas that can be produced with current technology.

The Usan field began crude-oil production in February, and Total's current share in the project is 24,000 barrels a day, Sinopec said. At peak output, Sinopec's share is expected to reach 26,000 barrels a day, the state-owned Chinese company added. 

Meanwhile, SIPC is expected to gain 27 million metric tons, or 542,000 barrels a day, of crude in 2012, its parent company said in January. SIPC owned 47 overseas projects in 23 countries at the end of 2011, it said.

SIPC plans to more than double its share of oil output from overseas projects to more than 50 million metric tons a year by 2015 from 22.88 million tons in 2011, it said.