Geothermal hot dry rock (HDRs) reserves in Shandong and Hebei, China https://www.thinkgeoenergy.com/studies-confirm-geothermal-hot-dry-rock-reserves-in-shandong-and-hebei-china/
Equivalent to 18.8 billion tons of standard coal. By comparing to 2019 figures, the reserves are 50 times the size of global oil.
https://journals.sagepub.com/doi/full/10.1177/0144598719895820