[Voiceover] China's largest oil-and-gas field in the country's northwest Ordos Basin has just celebrated a milestone recently - the production of more than 10,000 tons of shale oil in just one day. The Changqing oilfield produced 3.2 million tons of shale oil in 2024, which accounted for more than 52 percent of the country's total. A manager at the oilfield said the 10,000 per day production rate will play a significant role in the country's energy security. [Soundbite] Lei Qihong, Changqing oilfield manager: "The daily output of shale oil at Changqing oilfield exceeds 10,000 tons, making an annual production capacity of 3.65 million tons, comparable to that of a medium-sized oilfield. We plan to further enhance shale oil drilling efforts, aiming to reach an annual production of 4.5 million tons by 2030." [Voiceover] Currently, Changqing's cumulative shale oil output is more than 18.5 million tons. Since the 1970s, the oilfield's accumulated proven oil and gas reserves have accounted for about one-third of the country's total. [Restrictions: No access Chinese mainland]