Institute of Mining, Far Eastern Branch, Russian Academy of Sciences, Khabarovsk, Russia

A. N. Shulyupin, Director, Doctor of Engineering Sciences, ans714@mail.ru

The shortcomings of the interpretations of basic concepts in the domestic practice of development of geothermal resources are highlighted. Based on the analysis of the conceptual apparatus of mining sciences and classical thermophysics, geothermal resources are defined as a geothermal energy that can be extracted for effective use at the existing level of technology. Correct definitions of geothermal energy, geothermal fields and geothermal technologies are also proposed. It is shown that in the classification of georesources according to M. I. Agoshkov, geothermal resources can be classified as both the special fifth group and the first group (mineral deposits), taking into account the required presence of carriers of geothermal energy, which can be media in various physical states, and the presence of solid carriers is mandatory. The possibility of considering geothermal technologies as a branch of geotechnology is substantiated. The presence of both renewable and non-renewable types geothermal resources is noticed. Taking into account the main global trends in the use of geothermal resources, two most actively developing trends are identified: extraction of energy from shallow levels at a low but relatively stable temperature, using heat pumps and borehole (ground) heat exchangers; creation and operation of enhanced geothermal systems involving multidisciplinary collaborative research teams. It is emphasized that domestic R&D lags significantly behind the world level in both trends mentioned above.

1. Bulba E. E., Kuznetsov G. V., Shvaybovich M. I. Assessment of the prospects for using unconventional renewable energy sources in the next twenty years. Izvestiya Tomskogo politekhnicheskogo universiteta. Inzhiniring georesursov. 2022. Vol. 333, No. 2. pp. 164–172.
2. Lund J. W., Huttrer G. W., Toth A. N. Characteristics and trends in geothermal development and use, 1995 to 2020. Geothermics. 2022. Vol. 105. ID 102522.
3. Ghavidel A., Gracie R., Dusseault M. B. Design parameters impacting electricity generation from horizontal multilateral closed-loop geothermal systems in Hot Dry Rock. Geothermics. 2022. Vol. 105. ID 102469.
4. Huang G., Hu X., Ma H., Liu L., Yang J. et al. Optimized geothermal energy extraction from hot dry rocks using a horizontal well with different exploitation schemes. Geothermal Energy. 2023. Vol. 11. DOI: 10.1186/s40517-023-00248-4
5. Agoshkov M. I. Development of ideas and practice of c omplex mastering of soils. Moscow : IPKON AN SSSR, 1982. 25 p.
6. Trubetskoy K. N. Development of new ways in integrated mastering of subsoils. Moscow : IPKON AN SSSR, 1990. 11 p.
7. Kaplunov D. R., Rylnikova M. V. Renewable energy sources as a georesource in the system of technology-induced transformation in the Earth’s interior. Gornyi Zhurnal. 2015. No. 9. pp. 72–75.
8. Kiryukhin A. V. Geothermal fluid mechanics of hydrothermal, volcanic and hydrocarbon systems. Saint-Petersburg : Eko-Vektor, 2020. 431 p.
9. Boguslavskiy E. I. The use of subsoil heat energy. Saint-Petersburg : Naukoemkie tekhnologii, 2020. 435 p.
10. Kirillin V. A., Sychev V. V., Sheyndlin A. E. Technical thermodynamics : Textbook. Moscow : MEI, 2016. 495 p.
11. Arens V. Zh., Babichev N. I., Bashkatov A. D., Gridin O. M., Khrulev A. S. et al. Hydraulic borehole mining of minerals : Tutorial. 2^nd ed. Moscow : Gornaya kniga, 2011. 295 p.
12. Litvinenko V. S., Petrov E. I., Vasilevskaya D. V., Yakovenko A. V., Naumov I. A. et al. Assessment of the role of the state in the management of mineral resources. Journal of Mining Institute. 2023. Vol. 259. pp. 95–111.
13. Reinisch E. C., Ali S. T., Cardiff M., Kaven J. O., Feigl K. L. Geodetic measurements and numerical models of deformation at Coso Geothermal Field, California, USA, 2004–2016. Remote Sensing. 2020. Vol. 12, Iss. 2. ID 225.
14. Aryanfar Y., Alcaraz J. L. G. Exergy and exergoenvironmental assessment of a geothermal heat pump and a wind power turbine hybrid system in Shanghai, China. Geothermal Energy. 2023. Vol. 11. DOI: 10.1186/s40517-023-00250-w
15. Moghanni R., Hakkaki-Fard A., Hannani S. K. A comprehensive study on the performance of vertical ground-coupled heat pumps. Geothermics. 2023. Vol. 110. ID 102674.
16. Chong Q., Wang J., Gates I. D. Evaluation of closed-loop U-Tube deep borehole heat exchanger in the Basal Cambrian Sandstone formation, Alberta, Canada. Geothermal Energy. 2022. Vol. 10. DOI: 10.1186/s40517-022-00229-z
17. Luo Y., Yan T., Yu J. Integrated analytical modeling of transient heat transfer inside and outside U-tube ground heat exchanger: A new angle from composite-medium method. International Journal of Heat and Mass Transfer. 2020. Vol. 162. ID 120373.
18. Shulyupin A. N., Varlamova N. N. Current trends in the development of geothermal resources. Georesursy. 2020. Vol. 22, No. 4. pp. 113–122.
19. Zhang J., Xie J., Liu X. Numerical evaluation of heat extr action for EGS with tree-shaped wells. International Journal of Heat and Mass Transfer. 2019. Vol. 134. pp. 296–310.
20. Osgouei Y. T., Akin S. Experimental and numerical study of flow and thermal transport in fractured rock. Heat and Mass Transfer. 2021. Vol. 57, Iss. 6. pp. 1053–1068.
21. Chen Y., Huang L., Ajo-Frankli J., Bauer S. J., Baumgartner T. et al. Optimal design of 3D borehole seismic arrays for microearthquake monitoring in anisotropic media during stimulations in the EGS collab project. Geothermics. 2019. Vol. 79. pp. 61–66.
22. Butuzov V. A., Tomarov G. V., Alkhasov A. B., Aliev R. M., Badavov G. B. Geothermal energy of Russia: Resources, electric power generation, and heat supply. A review. Thermal Engineering. 2022. Vol. 69, No. 1. pp. 1–13.
23. Shulyupin A. N. Steam-lift production of geothermal fluid. Gornyi Zhurnal. 2019. No. 1. pp. 51–55.
24. Dyadkin Yu. D. Development of geothermal deposits. Moscow : Nedra, 1989. 229 p.