CNOOC Ltd and its partners may spend about 200 billion yuan to develop fuel deposits in the South China Sea in the nation's biggest push to tap reserves off the coast.

The investments between next year and 2020 include an estimated 15 billion yuan by parent China National Offshore Oil Corp to build deepwater drilling equipment, Luo Donghong, chief development engineer at CNOOC's Shenzhen unit, told reporters and analysts on Nov 22.

He didn't name the companies that will partner China's biggest offshore oil producer.