A worker conducts machinery check on the Crust 1 land-based drilling rig system in the Songliao Basin in northeast China, June 1, 2018. Crust 1, a land-based drilling rig, concluded its first mission on Saturday, putting China among the frontrunners in onshore drilling, along with Germany and Russia. Jointly developed by Jilin University and Sichuan-based Honghua Group, Crust 1 can dig as deep as 10,000 meters and is China's most advanced land-based drilling rig. (Xinhua/Xu Chang)