BP Plc and China National Petroleum Corp. will drill and upgrade wells to raise output from Iraq's largest oil field of Rumaila, Dhia al-Musawi, director general of Iraq's state-owned South Oil Co., said today.

They will drill new wells and upgrade existing ones over five years at the southern field of Rumaila, al-Musawi said in an interview. Production at Rumaila was about 1 million barrels a day as of the end of last year.

Than plan involves 1,250 wells, al-Musawi said, without being specific about the number of wells that will be drilled.

BP and CNPC signed a 20-year service contract with South Oil in November to triple output from Rumaila to 2.85 million barrels a day.

Rumaila may then become the second-biggest oil field by production in the world after Saudi Arabia's Ghawar, the London- based company said at the time. Once production is raised by 10 percent by the end of 2010 as planned, the two companies will start to recover development costs, BP, Europe's second-biggest oil company said. They will get a fee of $2 a barrel on incremental output, it said.

CNPC and partner BP Plc will take over full management of the oil field by June 30, China National Petroleum said in its online newsletter April 20.

BP has a 38 percent stake in the project, CNPC 37 percent and Iraq's State Oil Marketing Organization 25 percent.

Rumaila was the only oil field contract awarded by Iraq in June in the first bidding round since the U.S.-led invasion in 2003. Iraq signed 10 oil field development contracts last year. Iraq plans to raise oil production by about 60 percent to 6 million barrels a day by 2015 to upgrade its war-ravaged economy.