HARBIN, Nov. 28 (Xinhua) -- Daqing Oilfield Co., Ltd, a subsidiary of China's largest oil producer PetroChina, produced 30.87 million tonnes of oil equivalent at home and aboard in the first three quarters this year.

Its domestic facilities churned out 23.89 million tonnes of crude oil and 3.1 billion cubic meters of natural gas, while its overseas operations contributed 4.5 million tonnes of oil equivalent.

Its revenues and profit grew 15.4 percent and 184.6 percent year on year, according to the oil and gas producer.

In recent years, the firm has been seeking to increase its natural gas output with rising difficulties in extracting crude oil at its main production base, Daqing Oilfield.

Daqing Oilfield, the largest oilfield run by PetroChina in northeast China's Heilongjiang Province, was discovered in 1959. For many years, the oilfield had an annual output exceeding 50 million tonnes of crude oil, but output has shrunk due to dwindling reserves.