S Fu, J Fu, X Niu, S Li, Z Wu, X Zhou, J Liu - Acta Petrolei Sinica, 2020 - syxb-cps.com.cn
In 2019, PetroChina Changqing Oilfield Company discovered the Qingcheng oilfield,
China's largest shale oilfield, in the source beds of Chang 7 oil layer of Mesozoic Yanchang …