Application Of CSAMT In Geothermal Exploration Of Yishu Fault Zone

Energy is an important material basis for the survival and development of human society,and plays an important role in the development of national economy,industry and military.With the rapid development of the country's economy and the improvement of environmental requirements,the demand for new and green energy is increasing.As a new green environmental resource in the deep underground,geothermal has been paid more and more attention.The formation mechanism of geothermal resources determines the depth of its buried depth,and it is very difficult to explore,develop and utilize the geothermal resources.By analyzing the formation mechanism of geothermal energy,we can know that the geothermal system can be divided into sedimentary basin geothermal system and uplift mountain convection type.In the uplift mountain convective geothermal system,the fault structure is the main thermal reservoir and the channel for conducting water conduction,so in the early geophysical exploration,the geothermal resources are found mainly through the discrimination of the fracture structure,and the fault structure is also a hydrothermal enrichment area in the conductive geothermal system of the sedimentary basin.The success rate of geothermal resources exploration can be greatly improved by determining the occurrence,scale and burial depth of fractures.The controlled source audio magnetotelluric sounding method,as a geophysical method with greater depth of exploration,has high accuracy in searching for deep fracture structure,and has been applied in geothermal resources exploration.First of all,the theory of controlled source audio frequency magnetotelluric method is expounded in the light of the present situation of geothermal resources in Yishu Fault Zone.By setting different background resistivity geoelectric models,the corresponding characteristics of two,three and four low resistance fault zones are studied in depth.Secondly,the spatial distribution of geological structure,formation,fracture distribution and geothermal characteristics of the Yishu Fault Zone are analyzed in depth,and the four elements of geothermal resources in this area,namely heat source,thermal storage,cover layer and channel,are summarized.Finally,on the basis of the field survey,the measured data are retrieved and geological interpretation based on the regional geological data,and the geophysical well location and thermal storage range are determined by geophysical exploration.The conclusion of this paper shows that the controlled source audio magnetotelluric sounding method and its inversion interpretation results have a strong application in the field of geothermal exploration,and provide useful experience for the future exploration of geothermal resources in other areas.