干热岩勘查评价指标与形成条件  

Evaluation indexes and formation conditions of hot dry rock exploration

作　　者：刘德民[1] 张昌生 孙明行 韦梅华[2] 关俊朋[4] 康志强 熊爱民 周天禹 Liu Demin;Zhang Changsheng;Sun Minghang;Wei Meihua;Guan Junpeng;Kang Zhiqiang;Xiong Aimin;Zhou Tianyu(School of Earth Sciences,China University of Geosciences(Wuhan),Wuhan 430074,China;The First Hydrogeology Engineering Geology Team of Shanxi Province,Taiyuan 030024,China;Guangxi Institute of Geological Survey,Nanning 530023,China;Geological Survey Institute of Jiangsu Province,Nanjing 210018,China;China-Asean Geosciences Cooperation Center,Nanning 530023,China)

机构地区：[1]中国地质大学(武汉)地球科学学院,武汉430074 [2]山西省第一水文地质工程地质队,太原030024 [3]广西壮族自治区地质调查院,南宁530023 [4]江苏省地质调查研究院,南京210018 [5]中国-东盟地学中心(南宁),南宁530023

出　　处：《地质科技通报》2021年第3期1-11,共11页Bulletin of Geological Science and Technology

基　　金：中国地质大学(武汉)2019年第二批本科教学工程项目(ZL201925);广西干热岩选区预测与分级评价(2019016207);苏北盆地干热岩控热构造背景研究(2018016417)。

摘　　要：干热岩具有利用率高、无污染、储量巨大、分布较广、持续稳定、安全性好等特点,被全球公认为在21世纪能够取代化石能源的一种最优质的、可再生的新型清洁能源。目前对于干热岩的成因机理还没有定论,而对于干热岩的勘探寻找、远景区的圈定以及资源评价也有不同的观点,为了有利于干热岩勘探开发,本文在综述前人研究工作基础上,总结归纳了干热岩勘查评价指标,几个重要的指标及其特征如下。第一个指标是岩石圈厚度和莫霍面埋深,岩石圈厚度较小并且莫霍面埋深比较浅,是评价干热岩远景区的一个重要指标。莫霍面埋深较浅指示深部热源(幔源热)更加接近地表,故埋深较浅(较薄的厚度)并具有上隆的特征有利于深部的热量向上传导,为干热岩的孕热环境提供良好的条件。第二个指标是居里等温面,埋深较浅的居里等温面是干热岩远景区一个重要的评价指标。居里等温面是地球内部一个非常特殊的温度(热物质)界面,它不仅能指示地下温度场的分布特征,还可指示地壳深部热能分布特征,对干热岩及地震的成因研究具有十分重要的意义;如果居里面埋深较浅,则热量传导到地表的距离比较短,深部的热流活动更容易向地表传送,不仅是有利的高温干热岩孕热环境,也有利于储存的热能快速向上传导。第三个指标为地温梯度,地温梯度较大是寻找干热岩远景区的一个重要指标;如果一个地区具有较高的地温梯度(≥35℃/km),则随着深度的增加深部的地温增加较快,在相对较浅的地方就可以获得温度较高的岩石体。第四个指标是大地热流,大地热流值较大(≥75 mW/m 2)就指示地球深部有存在高温岩石体的可能;大地热流是地温场的综合性热参数,能够准确地反映区域内的地温场特征。第五个指标是新构造运动,这也是人们寻找干热岩时容易忽略的一个重要指标Hot Dry Rock has the characteristics of high utilization rate,pollution-free,huge reserves,wide distribution,sustained stability,good security,and so on.It is recognized globally as a new type of high-quality,renewable and clean energy that can replace fossil energy in the 21st century.At present,the genetic mechanism of Hot Dry Rock has not yet been concluded,and different opinions emerge on the exploration and search of Hot Dry Rock,the delineation of the prospective area,and the evaluation of resources.To facilitate the exploration and development of Hot Dry Rock,this paper summarizes the evaluation indexes of Hot Dry Rock exploration based on previous researches.Several important indexes and their characteristics are described as follows.The first index is the thickness of the Lithosphere and the depth of the Moho.The thickness of the Lithosphere is small and the depth of the Moho is shallow,which is an important index to evaluate the Hot Dry Rock prospect.The shallow buried depth of the Moho indicates that the deep heat source(mantle heat)is closer to the surface,so the shallow buried depth(thin thickness)and uplifting feature are conducive to the upward conduction of deep heat and provide advantageous conditions for the thermal environment of Hot Dry Rock.The second index is the Curie isotherm surface.The shallower buried Curie isotherm surface is an important evaluation index for the Hot Dry Rock prospective area.The Curie isotherm surface is a very special temperature(thermal material)interface inside the earth.It can not only reflect the distribution characteristics of the underground temperature field,but also the heat energy in the deep crust,which is of great significance to the study of Hot Dry Rock and earthquake genesis.If the Curie isotherm surface is buried shallowly,the distance of heat conduction to the surface is relatively short.The deep heat flow is easier to transfer to the surface,which is not only a favorable environment for heat generation of high-temperature Hot Dry Rock thermal environ

关 键 词：干热岩 评价指标 形成条件 勘查 

分 类 号：P314[天文地球—固体地球物理学]