**Acknowledgements**

This work was supported by National Key R&D Program of China (Grant No. 2016YFE0202200), the Fundamental Research Funds for the Central Universities (Grant No. 2652017070), Research Foundation of Key Laboratory of Deep Geodrilling Technology, Ministry of Land and Resources (Grant No. PY201805), International S&T Cooperation Program of China (Grant No. 2012DFR70160), and the National Natural Science Foundation of China (No. 41672365).
