The output of PetroChina's Changqing oilfield has reached 40,000 tonnes a day, a source with PetroChina said Monday.

The field in the Ordos Basin took 18 years to accomplish a daily output of 10,000 tonnes, while it took less than two years to rise from 30,000 to 40,000 tonnes, said the source.

Changqing oilfield features low permeability, low pressure and low production in oil reserves.

Chinese experts, however, had discovered two 200 million tonne oil reserves -- Ansai and Jing'an -- in the field.

Changqing's crude output increased 1.542 million tonnes in 2007 over a year earlier.

In the first quarter, the field pumped out 3.304 million tones of crude, up 9.53 percent from the January to March period a year earlier, marking a 37-year high in oil output, according to the website of CNPC, parent of PetroChina.

As one of CNPC's heavyweight oilfields, Changqing had targeted an annual oil and gas equivalent output of 30 million tonnes by 2009, said the website.

(Xinhua News Agency June 24, 2008)