The well determination for geothermal resource explorationin typical islands in Xiaoguan Island, Qingdao

The geological environment conditions in island area are relatively complex, with large topographical fluctuations, various types of landforms, and special geothermal geological conditions. Choosing appropriate methods for geothermal resource exploration and well location is of great significance for the exploration and development of geothermal resources. Taking the geothermal resource exploration on Xiaoguan Island in Qingdao City as an example, we comprehensively analyzed the geothermal condition and compared the advantages and disadvantages of geophysical prospecting methods for geothermal resource exploration. Besides, by combining audio magnetotelluric (AMT) sounding method with high precision electromagnetic spectrum (MES) method, we interpreted the results of the two geophysical prospecting methods, obtained a conceptual model of thermal storage in the island area, identified the location of geothermal wells, and successfully constructed a 1500 m-deep geothermal well with a daily water output of 121.2 m³ and a 39.2 ℃ of bottom hole temperature. This study justified the feasibility and effectiveness of applying AMT and MES methods to explore geothermal resources in the island area.