DAQING, Dec. 5 (Xinhua) -- Daqing Oilfield, one of China's largest energy production bases, announced on Friday that its Gulong shale oil block in northeast China has surpassed one million tonnes in annual output this year, marking the site's successful transition to scaled production.

Shale oil, defined as liquid hydrocarbons trapped within shale rock formations and extractable for refining, represents a widely distributed energy resource with reserves significantly exceeding conventional oil sources. It is vital to China's stable oil production and energy security.

In 2021, Daqing Oilfield established China's national demonstration zone for lacustrine shale oil at the Gulong block. Through five years of dedicated research and development, the operator has successfully developed five core technologies specifically designed for large-scale shale oil production, achieving a multiplied increase in output for five consecutive years.

As a subsidiary of China National Petroleum Corporation (CNPC), Daqing Oilfield has played a pivotal role in shaping China's modern petroleum industry. Since its discovery in 1959 in the northeastern province of Heilongjiang, it has produced over 2.5 billion tonnes of crude oil, accounting for 36 percent of the country's total onshore output.