Potential analysis of middle-deep geothermal resources in Xixian New Area

Abstract

The middle-deep sandstone in Guanzhong Basin is the main rich layer of geothermal resources. In recent years, the exploration and development of geothermal resources are mainly concentrated in Xianyang City, and the potential of geothermal resources in Xixian New Area is not clear. With focus on the basic geology conditions, tectonic and hydrogeology survey?the results show that the Xixian New Area is located in the central part of the Guanzhong Basin? the main thermal reservoirs include the Neogene Zhangjiapo Formation, Lantian-Bahe Formation and Miocene Gaoling Group, which are all sandstone pore-type thermal reservoirs with thick layered distribution. In particular, the Lantian-Bahe Formation and Gaoling Group have moderate burial depth with high thermal storage temperature and large water-yield capacity, which form the dominant thermal reservoirs for geothermal development and utilization in this area.
Combined with the structural location and geological characteristics of thermal storage in Xixian New Area, Monte Carlo method is used to simulate and estimate the expected annual recoverable geothermal resources in the middle and deep layers of the area, which is 3.70 × 1016J, equivalent to 126 million tons of standard coal.
It is estimated that the geothermal resources in this area can be used for heating in winter for about 1.76 × 108m2 energy-saving buildings according to the converted heat consumption of 0.21GJ /m2a. According to the new district planning, the total urban and rural construction land in Xixian New Area is 360km2, of which the urban construction land is 272km2. The new district has a population capacity of 2.72 million, which requires a building area of 1.36 × 108 m2 per capita of 50m2. Therefore, through reasonable planning, the medium-deep geothermal resources can theoretically fully meet the thermal energy demand of building heating in the planning area. Geothermal energy utilization is an important part of carbon dioxide emission reduction in the region, which is conducive to achieving regional carbon neutrality goals.