Characteristics and potential evaluation of geothermal resources in Guangxi

This paper is the result of geothermal resources survey engineering.

Objective In Guangxi, the geothermal resource is extensively distributed, and is a competitive low-carbon, renewable and clean energy. Up to now, the systematic research on the occurrence regulation, distribution characteristics and potential of geothermal resources is relatively weak, to a certain extent, which restricts the comprehensive development and utilization in Guangxi.

Methods In this paper, we systematically analyzed the structure of the crust and mantle layer, the present characteristics of the geothermal field and the distribution pattern of geothermal resources, based on the latest results of the survey and evaluation of shallow geothermal, hydrothermal and hot dry rock geothermal resources in Guangxi since the "Twelfth Five-Year Plan". And we chose different methods to evaluate the development and utilization potential of shallow geothermal energy resources, hydrothermal geothermal resources and hot dry rock geothermal resources.

Results The research shows that the geothermal resources are rich in Guangxi, with obvious occurrence rules and zoning characteristics. In 13 major cities, the shallow and hydrothermal geothermal resources are mainly developed through direct utilization, and the shallow geothermal resources are 1.23×10¹⁵ kJ/℃, the annual exploitable resources are 1.36×10¹² kJ/a, equivalent to 1.67×10⁸ t standard coal. And 24 warm(hot) springs points and 28 geothermal mining wells locating in Guangxi, the total amount of geothermal energy resources is 2.56×10¹⁷ kJ, which is equivalent to 87.58×10⁸ t of standard coal. On the other hand, the annual recoverable heat of geothermal fluid is 28.89×10¹² kJ/a, which is equivalent to 315.65×10⁴ t of standard coal. Finally, the potential of dry hot geothermal resources is great in Guangxi, within 3-10 km of the land area, the total amount of hot dry rock resources is 55.42×10⁴ EJ, which is equivalent to 18.91×10¹² t of standard coal, at a recoverable rate of 2% which is 75.94 times the 2020 Chinese primary energy consumption(4.98 billion tons). Therefore, it is becoming the most ideal replacement carrier for traditional fossil energy.

Conclusions Guangxi is lack of coal, oil and gas in the traditional energy field, and has rich wind, water and heat in the new energy field. The rational development and utilization of geothermal resources will contribute to the optimization of energy structure and the strategic adjustment of industrial structure in Guangxi, and help to achieve the "dual carbon goal".