Multi-electrode resistivity method and CSAMT method in geothermal exploration of Babei area in Huichang County, Jiangxi Province

Geothermal resources are a kind of green, low carbon and highly competitive renewable energy. The Babei area of Huichang County in Jiangxi Province is characterized by dense faults. In order to find out the characteristics of the attitude, scale and deep change of the fault structure in the exploration area so as to provide a basis for finding the layout of geothermal water drilling, the authors arranged three multi-electrode resistivity method test lines at the location of the known hot springs, and determined the validity of the geophysical method and the water guide fault in the survey area according to the principle of the shallow to deep exploration from the known to the unknown. On the basis of the preliminary interpretation results of multielectrode resistivity method, the controllable source audio magnetotelluric sounding method (CSAMT) was constructed according to the preliminary interpretation of multi-electrode resistivity method. It is concluded that two of the deep faults are the main thermal conductive structures in hot springs, that the faults cut deeply into the basement interface, and that the basement interface undulates obviously. At the same time, four low resistivity anomalous zones were delineated, of which the largest one is about 1000m in length, 240m in width and 200 m in height. It is the most advantageous water-bearing area and the direct basis in the search for geothermal water. It is suggested that drilling holes should be laid directly above the anomalous zones for verification. The hole depth is about 800m, which meets the depth control of deep and large faults and the base for low resistivity zones.