HARBIN, Jan. 2 (Xinhua) -- Daqing Oilfield Co. Ltd., a subsidiary of China's largest oil producer PetroChina, produced around 41.67 million tonnes of oil equivalent in 2018.

The oilfield's domestic facilities churned out 32.04 million tonnes of crude oil and 4.34 billion cubic meters of natural gas last year.

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.

Thanks to the effort, its natural gas output has recorded continuous growth over the past eight years. Daqing Oilfield, the largest oilfield run by PetroChina in northeast China's Heilongjiang Province, was discovered in 1959.