An analysis of the occurrence of the geothermal resources in Lanzhou

The first geothermal well was drilled by The Second Geology and Minerals Prospecting Institution of Geology and Minerals Bureau of Gansu Provice in the Qilihe area of Lanzhou.Comprehensive geophysical prospecting methods play a very important role in the geothermal resources exploration and the location selection of the exploitation well.Based on the analysis of the exploration data,the geothermal resources of the Lanzhou Basin is of low temperature and of the sedimentary basin type,and the occurrence of the geothermal resources is controlled by two large-scale NS-trending faults near the basin.The caprock of the geologic field consists of the Tertiary mudstone,and the reservoir,of the Tertiary sandstone and the Cretaceous conglomerate.The distribution of geothermal temperature is related to the lithology and depth.Higher thermal gradient appears in fine-grain strata.Temperature increases with depth.