Changqing oilfield, China's largest oil-and-gas field, saw its production exceed 60 million tons of oil - equivalent to crude oil and natural gas in 2020 - to hit a record high.

Located in Northwest China's Erdos basin, Changqing oilfield, with 50 years of history, has produced 24.5 million tons of crude oil and 44.5 billion cubic meters of natural gas (equivalent to about 35.5 million tons of crude oil) as of Sunday, according to China National Petroleum Corp, the operator of the oilfield.

It became the first oilfield in China to pass the 60 million ton mark in annual oil and gas output, a landmark in China's energy history, said the State-owned energy giant.

Having played an important role ensuring the country's energy security, supplying gas to more than 50 cities in north and northwest China, the oilfield's oil-and-gas production areas cover Northwest China's Shaanxi and Gansu, and North China's Shanxi provinces, as well as the Northwest China's Ningxia Hui and North China's Inner Mongolia autonomous regions.

Against globally depressed oil prices, the oilfield has been developing alternative energy sources, such as tight gas and shale oil, pushing up its annual output, China National Petroleum said.

As the largest natural gas producer in China, the oilfield is contributing to China's ongoing efforts to replace coal with clean energy, such as natural gas and hydropower. China has promised to peak carbon dioxide emissions by 2030 and achieve carbon neutrality by 2060.

"Changqing Oilfield has so far produced 468.6 billion cubic meters of natural gas. This is equivalent to replacing 562 million tons of standard coal and reducing carbon emissions by 1.53 billion tons," said Wu Zheng, manager of the oilfield's gas development division.

The oilfield plans to raise its annual output to 68 million tons of oil equivalent by 2025.