Methodology and Application of Deep Geothermal Sounding in Low-Resistance Cover Areas  

低阻覆盖区深层地热探测方法及应用实例

作　　者：Qiao Yong Zhang Hui 乔勇;张慧(长江大学地球科学学院,武汉430100;华北水利水电大学地球科学与工程学院,郑州450000;水利水电规划设计总院,北京100120)

机构地区：[1]College of Geosciences,Yangtze University,Wuhan,430100,China [2]College of Geosciences and Engineering,North China University of Water Resources and Electric Power,Zhengzhou 450000,China [3]China Renewable Energy Engineering Institute,Beijing,100120,China

出　　处：《Applied Geophysics》2025年第1期99-109,233,234,共13页应用地球物理(英文版)

基　　金：National Natural Science Foundation of China(No 52174048).

摘　　要：Taking the Qihe area as an example,this paper compared various geophysical exploration methods in view of the problems of urban construction,deep thermal reservoir burial,and vast overlying low-resistance shield layer in deep karst geothermal exploration.A Controlledsource audio magnetotelluric(CSAMT)method was taken to overcome the problems and detect deep stratigraphic structures in the study area.The acquisition parameters of CSAMT were optimized to take into account the exploration depth and signal-to-noise ratio.The distortion of data in the near and transition zone was eliminated by the inversion of equivalent whole-region apparent resistivity,so as to achieve the purpose of deep sounding.Based on the resistivity profi le resulting from the proposed CSAMT method,three faults were inferred and one low-resistance anomaly zone in the area was traced.The results of the profile interpretation were verified by drilling.The inferred stratigraphic boundaries and low-resistance anomaly zone were basically in agreement with the drilling results,thereby proving the eff ectiveness of the CSAMT method for deep geothermal exploration in low-resistance coverage areas.This method could provide technical support for deep geothermal exploration in similar areas.本文以齐河地区为例,针对深层岩溶地热探测面临的城区施工、热储埋藏深、上覆巨厚“低阻屏蔽”层等问题,综合对比多种地球物理测深方法后,在研究区实施了可控源音频大地电磁法对深部地层结构进行探测。根据可控源音频大地电磁法的电阻率剖面,推测出3条断裂并圈定了区内1个低阻异常区。通过钻探验证,剖面解释成果与钻探揭露的地层界线吻合较好,低阻异常区与钻探结果基本吻合,证明了可控源音频大地电磁方法对低阻覆盖区下的深层地热勘探的有效性,可为类似地区的深部地热探测提供技术支持。

关 键 词：CSAMT low-resistivity shielding Ordovician karst geothermal reservoir fracture zone whole region apparent resistivity 

分 类 号：P31[天文地球—固体地球物理学]