Ru County is rich in hot dry rock geothermal resources with a 98℃ hot spring distributed. However, research on the resources is scarce. This study evaluated the hot dry rock geothermal resource in Ru County on the basis of borehole temperature measurement and terrestrial heat flow survey. The results show that the average geothermal gradient was 18.7℃/100 m with a max of 35.2℃/100 m and the heat flow changed between 60 and 170 MW/m². Heat came from the deep magma in the geothermal field. The geothermal reservoir was composed of dense fractures produced by sub-faults in the upper part of F1 fault and F3 fault. The cover of the geothermal reservoir contained exposed granite on the east side of the Reshui River and Sinian slate on the west side. According to our model, the temperature was 260℃ on the lower site and 255℃ on the upper site. The stratum thickness is about 3500-4000 m above the geothermal reservoir. In Ru County, the geothermal reservoir has a shallow burial depth and a high temperature belonging to a suitable destination area of hot dry rock development.

hot dry rock  /  geothermal resource  /  heat flow  /  Ru County