Spatial carrier of geothermal system in eastern Sichuan fold zone——interconnected fault system： A case study of geothermal well in Moujia Town, Guang'an, Sichuan

Under the background of "Carbon peak and Carbon neutral", it is imperative to develop low carbon energy. As an important clean energy source, the exploration and utilization of geothermal resources need to be intensified. In the eastern Sichuan fold belt, which is rich in geothermal resources, the limestone stratum of Triassic Jialingjiang Formation is considered as a favorable thermal reservoir and the main target of geothermal exploration. However, the fact that many drilling in Jialingjiang Formation did not produce geothermal water and the geothermal water from other Formation calls into question the above statement. In this paper, in the geothermal exploration area of Mujia Town, it is found that there are interconnected fault systems in the deep part of the exploration area through the audio-frequency magnetotelluric sounding. Using this as the target body for drilling verification, geothermal water with daily water inflow >12000m³ and 42°C was obtained. Based on this, it is speculated that the interconnected fault system may be the spatial carrier of the geothermal system in the eastern Sichuan fold belt. By detecting the deep structural features of two natural hot springs in Huayingshan and Tongluoshan and one waterless borehole, the universality of water control by faults in the eastern Sichuan fold belt is confirmed. Combined with the seepage analysis, it is considered that taking the interconnected fault system as the exploration target body is expected to realize the sustainable development of geothermal resources in the eastern Sichuan fold belt. This study will provide some reference for the research on the ubiquitous geothermal genetic mechanism, exploration practice and sustainable development and utilization in the belt.