China National Petroleum Corp, the country's largest oil producer, has discovered four oil blocks with proven reserves of 250 million tons, a company publication said yesterday.

These discoveries, made by its Daqing Petroleum unit, are in Taidong, Talaha and Zhaoyuan in northeastern Heilongjiang Province and Hailar in neighboring Inner Mongolia Autonomous Region, the China Oil News reported.

"In the first half, the Daqing exploration team has placed nearly 20 wildcat wells in these areas and most of them show good reserve result," the report said.

China, which turned into a net oil importer, is also pumping efforts to explore domestic oil and gas fields to fuel an economy which expanded 10.9 percent in the first half.

China now has proven oil reserves of some 2.4 billion tons.

Basins in the Xinjiang Uygur Autonomous Region in the remote northwest and the aging Daqing oilfield, China's biggest, in the northeast are among the main oil producing regions in the country.

The Daqing field can maintain production for at least another 50 years using more advanced extraction techniques, Daqing Mayor Han Xuejian was reported as saying last month.

Production from the oilfield will be maintained at last year's level of 45 million tons for the next five years, Han noted.

A lucrative upstream oil and gas production business is expected to give PetroChina Co, the Hong Kong-listed unit of CNPC, another record first-half profit as it reports interim results tomorrow.

Meanwhile, a China Securities Journal report said yesterday that PetroChina and Royal Dutch Shell Plc are bidding for a stake in Beijing Tongyi Petroleum Chemical Co, a leading domestic private lubricant producer.

Editor: Yan