综合物探技术在济南北部地热勘查中的应用

Application of integrated geophysical exploration technology in the geothermal exploration of northern Jinan

济南地热资源极为丰富,热储类型包括奥陶—寒武系岩溶裂隙热储、新近系—古近系碎屑岩类孔隙裂隙热储两种。本次地热勘查工作在济南北部大桥镇开展,热储类型为奥陶—寒武系岩溶裂隙热储,旨在通过物探剖面测量工作,查明地层、断裂构造分布情况和热储层的埋深,推断与控热、导热有关的断裂构造的产状及空间形态,圈定地热井施工靶区,优选地下水富水有利部位开展钻探验证。在资料搜集基础上,通过开展直流电测深、可控源音频大地电磁测量及大地电磁测量工作,对工作区断裂构造进行解释推断并对含水情况进行对比分析,优选地热靶区有利部位施工一口地热探采结合井,完井深度1532.06 m,静水位埋深13.03 m,孔口水温50.1℃,涌水量132.998 m^(3)/h,降深18.27 m。

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 1532.06 m,a static-water burial depth of 13.03 m,a wellhead water temperature of 50.1℃,a water yield of 132.998 m^(3)/h,and a dropdown depth of 18.27 m.