Application of integrated geophysical exploration technology in the geothermal exploration of northern Jinan
Ji'nan possesses highly abundant geothermal resources,which are hosted by Ordovician-Cambrian karst-fissured geothermal reservoirs and Neogene-Paleogene clastic pore-fissure geothermal reservoirs.The geothermal exploration in this study focuses on the Or-dovician-Cambrian karst fissured geothermal reservoirs in Daqiao Town in northern Ji'nan.Through geophysical profile measurements,this study aims to identify the distributions of strata and fault structures and the burial depths of geothermal reservoirs,infer the atti-tudes and spatial morphologies of fault structures associated with heat control and conduction,delineate the target area for geothermal well construction,and conduct drilling verification in the favorable underground water-rich position.Building on the collected data,this study interpreted and inferred the fault structures in the study area and comparatively analyzed the water-bearing properties by emplo-ying direct-current sounding,controlled source audio magnetotellurics,and magnetotelluric survey.A geothermal exploration and pro-duction combined well was constructed in a favorable position of the geothermal target area,manifesting a completion depth of 1 532.06 m,a static-water burial depth of 13.03 m,a wellhead water temperature of 50.1℃,a water yield of 132.998 m3/h,and a dropdown depth of 18.27 m.