Application of integrated geophysical techniques in geothermal exploration in Binhai County, Jiangsu Province

Abstract

Integrated geophysical technology is a necessary and effective means for geothermal exploration. However, integration of geophysical technology for large-scale surveys with those for geothermal reservoir localization is still in development. This study used the controlled source audio-frequency magnetotelluric method technology for large-scale exploration to obtain underground electrical structure information and micromotion detection technology to obtain underground wave velocity structure information. The combination of two detection technologies was used for local identification of geothermal reservoirs. Further, auxiliary correction and inversion constraint were implemented through the audio magnetotelluric sounding technology for maximum authenticity restoration of the near- and transition-field data. Through these technology improvements, a geothermal geological model was established for the Binhai County of Jiangsu Province in China and potential geothermal well locations were identified. On this basis, a geothermal well was drilled nearly 3000 m deep, with a daily water volume of over 2000 m³/day and a geothermal water temperature of 51°C at the well head. It is found that predictions using the above integrated geophysical exploration technology are in good agreement with the well geological formation data. This integrated geophysical technology can be effectively applied for geothermal exploration with high precision and reliability.