Oil worker Wang Yicheng takes crude oil samples at Shunbei oil-gas field of China Petrochemical Corporation (Sinopec Group) in Xayar County, northwest China's Xinjiang Uygur Autonomous Region, Sept. 25, 2019. Located in the northern margin of the Taklimakan Desert, Shunbei oil-gas field is one of the deepest oil and gas reservoirs in the world with an average depth of 7300 meters and a maximum depth of 8600 meters. Due to the remote location and inconvenient transportation, the oil workers could have some days off after they had worked continuously for two to four months. (Xinhua/Cai Yang)