Test and effect of time-frequency electromagnetic method in geothermal exploration in urban interference area

Abstract

The mid-deep geothermal resource is one of the important clean energy sources for winter heating in northern cities. Geophysical methods play an important role in geothermal exploration, but the effect of geophysical methods is not good because of various types of serious interference in urban areas. This paper introduces a new high-power time-frequency electromagnetic technology and its geothermal exploration test in Dongli District of Tianjin. The test proves that this method has the characteristics of strong anti-interference ability, high signal-to-noise ratio and high construction efficiency. It can collect objective and real data in geothermal exploration in urban areas with stratigraphic physical properties. Through fine data processing, the stratigraphic structure and karst development in the test area have been ascertained, the location, trend and nature of Cangdong fault and its secondary faults have been ascertained, and five favorable geothermal areas have been delineated, which provides geological basis for deep geothermal resource evaluation and drilling.