摘要
地热能凭借其稳定性、经济性等优势已成为新型清洁能源体系构建的关键方向。电磁法作为解析地热系统电性结构的核心地球物理手段,其方法体系呈现显著互补特征:大地电磁法(magnetotelluric,简称MT)利用天然交变电磁场,具有探测深度大、对深部低阻异常体灵敏等特点,但极易受到电磁环境噪声的影响;广域电磁法(wide-field electromagnetic method,简称WFEM)采用人工场源,抗干扰性能强、对浅部异常体及细小断裂分辨率较高。为充分发挥MT和WFEM的优势互补效应,采用二维联合反演方法,探讨了MT与WFEM联合反演在地热勘探过程中的可行性和有效性。理论模型合成数据测试表明,相比于单独反演结果,MT与WFEM二维联合反演能够更为清晰地刻画地热系统的盖层及热储层分布特征。最后,对山西大同地热区实测MT及WFEM数据分别单独反演和联合反演,并进行了对比分析。研究结果显示联合反演结果要显著优于MT或WFEM单独反演结果,有助于圈定出地热系统的重要组成部分。根据联合反演所得的电阻率分布结构,结合测区地质及其他资料,推断出了该地区地热系统的概念模型。
[Objective]Geothermal energy,owing to its stability and economic advantages,has become a crucial direction in the construction of new clean energy systems.[Methods]Electromagnetic methods are core geophysical techniques for resolving the electrical structure of geothermal systems and exhibit distinct complementary features.The magnetotelluric(MT)method uses natural alternating electromagnetic fields with the advantages of high detection depth and sensitivity to deep low resistance bodies,but it is susceptible to the influence of electromagnetic environmental noise.Wide-field electromagnetic method(WFEM)utilizes artificial field sources,exhibiting strong anti-interference capabilities and showing higher resolution for shallow anomalous bodies and small fractures.This study explores the complementarity and effectiveness of MT and WFEM in geothermal exploration through a twodimensional joint inversion method.[Results]Theoretical models and synthetic data tests have shown that twodimensional joint inversion combines the respective advantages of MT and WFEM,and can more clearly characterize the cap rock and thermal reservoir structure of geothermal systems.This paper conducted a joint inversion study on the measured data of MT and WFEM in a geothermal area in Datong,Shanxi,China.The results showed that the resistivity distribution obtained from the joint inversion clearly characterized shallow fault channels and deep thermal reservoirs.[Conclusion]Based on the resistivity structure model obtained from joint inversion and other geological data,a conceptual model of the geothermal system in the region was constructued,providing a reference basis for the precise exploration of geothermal resources in the future.
作者
谢子豪
陈宇峰
刘磊
周文龙
廖卫阳
杨鑫
XIE Zihao;CHEN Yufeng;LIU Lei;ZHOU Wenlong;LIAO Weiyang;YANG Xin(School of Geophysics and Geomatics,China University of Geosciences(Wuhan),Wuhan 430074,China;First Hydrogeological Engineering Geological Exploration Institute,Anhui Provincial Geological Exploration Bureau,Bengbu Anhui 233000,China;Hubei Provincial Key Laboratory of Resources and Ecological Environment Geology,Wuhan 430034,China;Geophysical Exploration Brigade of Hubei Geological Bureau,Wuhan 430056,China)
出处
《地质科技通报》
北大核心
2025年第4期368-378,共11页
Bulletin of Geological Science and Technology
基金
湖北省地质局地质科研项目“地下空间地质结构与资源探测技术应用研究”(KJ2023-37)
资源与生态环境地质湖北省重点实验室开放基金资助项目(HBREGKFJJ-202310)。
关键词
地热勘探
地热系统
大地电磁法
广域电磁法
二维联合反演
山西大同
geothermal exploration
geothermal system
magnetotellurics(MT)
wide-field electromagnetic method(WFEM)
two-dimensional joint inversion
Datong,Shanxi Province
