Aerial view of Daqing, northeast China's Heilongjiang

Aerial photo taken on May 25, 2021 shows the statue of "Iron Man" Wang Jinxi, an oil worker who devoted his life to the development of the petroleum industry, in Daqing, northeast China's Heilongjiang Province. China's Daqing Oilfield announced on Aug. 25 the discovery of a major shale oil field with predicted geological reserves of about 1.27 billion tonnes. Discovered in 1959, Daqing Oilfield has made a significant contribution to China's modern petroleum industry system. It also steps up efforts to improve its ecological environment in recent years. (Xinhua/Wang Jianwei)

Aerial photo taken on Sept. 8, 2021 shows a residential area in Daqing, northeast China's Heilongjiang Province. China's Daqing Oilfield announced on Aug. 25 the discovery of a major shale oil field with predicted geological reserves of about 1.27 billion tonnes. Discovered in 1959, Daqing Oilfield has made a significant contribution to China's modern petroleum industry system. It also steps up efforts to improve its ecological environment in recent years. (Xinhua/Wang Jianwei)

Aerial photo taken on Sept. 9, 2021 shows the PetroChina Daqing Petrochemical Company in Daqing, northeast China's Heilongjiang Province. China's Daqing Oilfield announced on Aug. 25 the discovery of a major shale oil field with predicted geological reserves of about 1.27 billion tonnes. Discovered in 1959, Daqing Oilfield has made a significant contribution to China's modern petroleum industry system. It also steps up efforts to improve its ecological environment in recent years. (Xinhua/Wang Jianwei)

Aerial photo taken on Sept. 8, 2021 shows a demonstration zone of Daqing Oilfield in Daqing, northeast China's Heilongjiang Province. China's Daqing Oilfield announced on Aug. 25 the discovery of a major shale oil field with predicted geological reserves of about 1.27 billion tonnes. Discovered in 1959, Daqing Oilfield has made a significant contribution to China's modern petroleum industry system. It also steps up efforts to improve its ecological environment in recent years. (Xinhua/Wang Jianwei)

Aerial photo shows the sunset view of Daqing Oilfield in Daqing, northeast China's Heilongjiang Province, May 24, 2021. China's Daqing Oilfield announced on Aug. 25 the discovery of a major shale oil field with predicted geological reserves of about 1.27 billion tonnes. Discovered in 1959, Daqing Oilfield has made a significant contribution to China's modern petroleum industry system. It also steps up efforts to improve its ecological environment in recent years. (Xinhua/Wang Jianwei)

Aerial photo taken on May 26, 2021 shows oil storage tanks at Daqing Oilfield in Daqing, northeast China's Heilongjiang Province. China's Daqing Oilfield announced on Aug. 25 the discovery of a major shale oil field with predicted geological reserves of about 1.27 billion tonnes. Discovered in 1959, Daqing Oilfield has made a significant contribution to China's modern petroleum industry system. It also steps up efforts to improve its ecological environment in recent years. (Xinhua/Wang Jianwei)