中国地质2025，Vol.52Issue(2)：438-451,14.DOI:10.12029/gc20231115001
青海共和盆地恰卜恰深部花岗岩热储时频电磁法探测及干热岩体预测
Deep-seated granite thermal reservoir exploration and hot dry rock potential assessment in the Qiabuqia Area,Gonghe Basin,Qinghai:A time-frequency electromagnetic method approach
摘要
Abstract
This paper is the result of geothermal geological survey engineering. [Objective]The Qiabuqia area within China's Gonghe Basin represents a key research zone for granite-hosted hot dry rock(HDR)systems.This study systematically investigates the caprock thickness variation and granite basement topography while elucidating the spatial configuration of granitic bodies to establish predictive models for HDR reservoir distribution.[Methods]Innovatively applying the Time-Frequency Electromagnetic(TFEM)method-traditionally employed in deep hydrocarbon exploration-to HDR characterization,we implemented a comprehensive workflow encompassing advanced data preprocessing,electrical parameter optimization,and constrained inversion modeling.Integrated interpretation of resistivity profiles with multi-source datasets(geological mapping,borehole logs,and auxiliary geophysical surveys)enabled three-dimensional reconstruction of stratigraphic architecture,granitic intrusion geometry,and HDR reservoir characteristics.[Results](1)TFEM demonstrates exceptional capability in resolving electrical stratigraphy within 10 km depth.Resistivity profiles reveal a tripartite H-type structure comprising a sub-high-resistivity superficial layer(900-1400 m thickness,eastward-thinning),an intermediate conductive zone,and a high-resistivity basement.Granitic bodies exhibit A-type resistivity progression with depth,featuring westward-deepening top surfaces(-900 to-2900 m elevation).(2)Thermal logging-constrained models delineate distinct spatial configurations of the Qiabuqia and Dalianhai HDR reservoirs,demonstrating strong correlation with structural highs.[Conclusions](1)Thermo-structural analysis identifies competent batholiths and stocks as preferential heat flow conduits,serving as prime HDR exploration targets.(2)This leads to the distribution characteristics of granitic bodies,which are deep rock bases,middle rock strains and shallow rock beds.(3)Resistivity anomalies within granitic masses reflect structural integrity gradients,with batholiths and stocks exhibiting superior mechanical continuity compared to fractured sill complexes.关键词
地热发电/时频电磁法/花岗岩/干热岩/恰卜恰地区/共和盆地/青海省/地热地质调查工程Key words
geothermal power generation/time-frequency electromagnetic method/granite/hot dry rock/Qiabuqia area/Gonghe basin/Qinghai Province/geothermal geological survey engineering分类
地质学引用本文复制引用
程正璞,魏强,连晟,张海江,胡文广,米晓利,雷鸣,李戍,于蕾..青海共和盆地恰卜恰深部花岗岩热储时频电磁法探测及干热岩体预测[J].中国地质,2025,52(2):438-451,14.基金项目
中国地质调查局项目(DD20190131、DD20211336、DD20230018)资助. Supported by the projects of China Geological Survey(No.DD20190131,No.DD20211336,No.DD20230018). （DD20190131、DD20211336、DD20230018）
