地热地球物理勘探新进展

地热作为一种清洁能源具有巨大的开发潜力,将在我国的经济发展中起到巨大的作用.在传统的热水型地热开发的基础上,国际上非常重视热干岩(Enhanced Geothermal)型地热的勘探开发.在这两类地热勘查和开发中,地球物理方法具有非常重要的作用.本文从地热系统的目标体岩石的地球物理性质出发,分析岩石的地球物理性质与温度、压力和含水量等影响因素的关系.例如随着温度的升高,岩石会出现去磁、电阻率降低、密度降低、弹性波速度也现明显降低等现象.进而分析地球物理方法应用到具体的地热勘查地质-地球物理异常模型.结合国际上21世纪以后的新方法技术,分析了重磁、电、地震方法在利用由于岩石温度的升高而出现的特殊地球物理现象,并应用于地热勘探.通过国内外实例介绍了各种地球物理勘探方法在地热勘查中成功应用,为进一步提高我国地热勘查水平,提供一些参考.

Advancement of geothermal geophysics exploration

Geothermal energy is a clean energy with great development potential and it will play a tremendous role in China’s economic development.Base on the traditional hot-water geothermal development,Enhanced Geothermal are paid much attention to exploration and development in many countries.Geophysical methods play important rule in the two types of geothermal exploration and development.In this paper,we discuss the petrophysical properties of geothermal system,and analyze the rock physical properties such as temperature,pressure and moisture content of the target rock or geological body.Especially there are great changes of rock properties while increasing with temperature,such as the demagnetization,lower resistivity,lower density and low elastic wave velocity.The geophysical properties can be applied in geophysical exploration,and help to analyze the geological-geophysical anomaly model in geothermal exploration.We introduce the advanced geophysical methods and technologies developed in the last few years,analyze application of magnetic and gravity,electrical and electromagnetic method,seismic methods due to rock properties changed with temperature.We introduce the cases in the geothermal exploration and directly applied to geothermal exploration.We hope the new methods can be used as important references in geothermal exploration.