Investigation and evaluation of shallow geothermal energy resources in key areas of Chengdu

In order to achieve carbon peaking and carbon neutrality, shallow geothermal energy as an energy-saving and environmental-friendly energy, its exploration and utilization should be strengthened urgently. Based on the field thermal response test and the pumping and recharging tests, hydrogeological and thermal physical parameters were obtained, and the suitability evaluation of shallow geothermal energy in Chengdu was carried out by using the analytic hierarchy process. The estimated evaluation of shallow geothermal energy heat capacity, heat exchange power and resource potential were obtained. The measured average formation temperature above 200 m in the study area of Chengdu is 18.59-19.76℃, and the average thermal conductivity of the formation is between 1.89-3.12 W/m·℃. The shallow geothermal energy in Chengdu is suitable for the development of groundwater and ground source heat pump system. The area of suitable area accounts for 16.36%, the relatively suitable area accounts for 19.72%, and the unsuitable area accounts for 63.92. Except for the abandoned Mangniu Mine area, all areas are suitable and relatively suitable for the development of ground source heat pump system. The total cooling power of shallow geothermal energy in summer is 1.19×10⁷ kW, and the cooling area is 1.98×10⁸ m². The total heating power in winter is 1.48×10⁷ kW, and the heating area is 1.57×10⁸ m². It is estimated that the development of shallow geothermal energy in Chengdu can save 1.69 million tons of standard coal per year, and reduce the emission of various types of waste gas pollution by about 4.25 million tons. The effect of energy saving and emission reduction is remarkable.