高温作用下干热岩岩石物理实验及岩石物理建模研究  

Rock physics experiment and rock physical modeling of hot dry rock under high temperature

作　　者：高万里 赵惊涛 王化伟 Gao Wanli;Zhao Jingtao;Wang Huawei(College of Geoscience and Surveying Engineering,China University of Mining and Technology-Beijing,Beijing 100083,China)

机构地区：[1]中国矿业大学(北京)地球科学与测绘工程学院,北京100083

出　　处：《矿业科学学报》2023年第6期758-767,共10页Journal of Mining Science and Technology

基　　金：国家重点研发计划(2020YFE0201300)。

摘　　要：为探究干热岩储层物性参数随温度变化的规律,本文对青海共和盆地29块干热岩样品进行高温岩石物理实验,分析了样品速度、磁场强度、电阻率等物性参数随温度变化的规律。研究结果表明:①岩石样品随着温度升高,密度逐渐减小,但衰减幅度不足1%;②样品纵横波速度受温度变化的影响较大,在120~180℃之间大幅衰减,纵波速度下降约1500 m/s,横波速度下降约800 m/s;③在120℃时,磁场强度达到峰值,数值为室温下的7倍;④电阻率随温度升高呈现波动性变化,数值在10~25Ω·m范围内变化。基于实验结果,结合经典的Gassmann方程和流体替换模型,定量分析了孔隙度和温度对纵波速度的影响:当孔隙度为0.025时,样品纵波速度随着温度的升高下降约600 m/s,当孔隙度为0.1时,样品纵波速度随着温度的升高下降约1000 m/s。Currently,the investigation and monitoring of geothermal energy face significant challenges,and a lack of understanding regarding the variations in physical parameters of hot dry rock reservoirs with temperature is a crucial factor.In this study,29 hot dry rock samples from the Gonghe Basin in Qinghai Province were subjected to high-temperature petrophysical experiments to analyze the changing patterns of physical parameters with temperature.Results show that:①The density of rock samples grad-ually decreases with temperature,albeit with an attenuation range of less than 1%.②The temperature change exerts a substantial influence on the P-wave velocity and S-wave velocity of the samples,resul-ting in significant attenuation between 120℃and 180℃,with respective reductions of approximately 1500 m/s and 800 m/s.③A peak magnetic field intensity,seven times greater than at room temperature,is reached at 120℃.④The resistivity fluctuates with increasing temperature,whose values ranges from 10 to 25Ω·m.Based on these experimental results and with the combination of the classical Gassmann equation and fluid substitution models,this study made a quantitative analysis on the impacts of porosity and temperature variations on longitudinal wave velocity.The outcomes indicate that a porosity of 0.025 resulted in a decrease of approximately 600 m/s in the longitudinal wave velocity with increasing tem-perature,whereas a porosity of 0.1 caused a decrease of approximately 1000 m/s under the same con-ditions.

关 键 词：岩石物理 干热岩 青海共和盆地 高温 岩石物理建模 

分 类 号：P631[天文地球—地质矿产勘探]