Occurrence rules and resource estimation of shallow geothermal energy in Guanzhong Basin
ZHOU Yang1,2, HONG Zenglin1,3, ZHANG Hui1,2, CAO Xiaofan4, MU Genxu1,2
1.Shaanxi Institute of Geological Survey, Xi’an 710054,China; 2.Shaanxi Hydrogeology Engineering Geology and Environmental Geology Survey Center,Xi’an 710068, China; 3.School of Automation, Northwestern Polytechnical University,Xi’an 710072, China; 4.School of Geology and Environment Engineering, Xi’an University of Science and Technology, Xi’an 710054, China
Abstract：This paper analyzes the exploitation and utilization as well as the occurrence and formation pattern of geothermal energy in Guanzhong Basin through field investigation and indoor analysis. The resources were also estimated, and different geomorphic units and the characteristics of thermal properties of rocks and soils with different lithology were also summarized, with the calculation of the depth of the constant temperature layer and the earth heat flow values in the shallow layers. The formation patterns of geothermal energy in Guanzhong Basin are mainly thermal conduction type and thermal convection type. The thermal conductivity geothermal resources are mainly distributed in intact geological blocks such as Xi’an sag and Gushi sag, while the thermal convection geothermal resources are mainly distributed in areas where deep faults directly communicate with the surface and in the vicinity of the fault zone. In this paper, the analytic hierarchy process was applied in the suitability division of shallow geothermal energy in Guanzhong Basin. It is considered that Guanzhong Basin is basically suitable or less suitable for buried tube ground-source heat pump system. While the suitable and less suitable area of groundwater ground-source heat pump system is mainly distributed in the central floodplain and the terrace area of the basin. According to heat storage method, the heat capacity of shallow geothermal energy in Guanzhong Basin is 1.38×1016 kJ/℃. The results show that the shallow geothermal reserves in Guanzhong Basin are huge and the development prospects are excellent.
2020, Vol. 7 
