含随机分布裂隙岩石饱和状态下电阻率数值计算研究  

Numerical calculation of electrical resistivity of rocks with randomly distributed fractures in saturated state

作　　者：王祖坤 宋雷[1] 王启睿 任建威 李海鹏[1] 何亚梦 WANG ZuKun;SONG Lei;WANG QiRui;REN JianWei;LI HaiPeng;HE YaMeng(State Key Laboratory for Geomechanics and Deep Underground Engineering,China University of Mining and Technology,Xuzhou 221000,China;Institute of Defense Engineering,AMS,PLA,Luoyang 471023,China)

机构地区：[1]中国矿业大学深部岩土力学与地下工程国家重点实验室,徐州221000 [2]军事科学院国防工程研究院,洛阳471023

出　　处：《地球物理学进展》2024年第3期1141-1151,共11页Progress in Geophysics

基　　金：江苏省重点研发计划项目(BE2022709);国家自然科学基金项目(41974164);中央高校基本科研业务费资金资助(2021GJZPY15)联合资助。

摘　　要：由于岩石损伤状态的变化会导致其电阻率的改变,故而解析岩石损伤与其电阻率间的定量关系,有助于采用电阻率法辅助损伤岩石分级评价.针对饱和盐水地层条件,为确定含随机分布裂隙岩石电阻率与其自身损伤状态参数间的关系.本文以裂隙数量标度岩石损伤程度,构建了损伤岩石模型,并基于有限差分法提出了损伤岩石电阻率的数值计算方法,进行了不同基体电阻率和盐水电阻率水平、不同损伤程度的岩石电阻率数值计算.结果表明,基体电阻率和盐水电阻率以及岩石损伤程度对岩石电阻率均有影响,相同地层条件下,损伤岩石的电阻率是表征岩石损伤程度的可靠参数.采用岩石电阻率推算岩体的工程参数有一定随机性,但仍能在统计均值上反映岩体的损伤程度.本文所获得的回归关系式运用及对其随机性的讨论对岩石损伤程度分级评价具有积极意义.Due to the changes in rock damage state leading to changes in its electrical resistivity,analyzing the quantitative relationship between rock damage and its electrical resistivity can help to use the electrical resistivity method to assist in the grading evaluation of damaged rocks.For saturated saline formation conditions,in order to understand the quantitative relationship between the resistivity of rocks with randomly distributed fractures and their own parameters,this paper constructed a damaged rock model,proposed a numerical calculation method for the resistivity of damaged rock,and performed numerical calculations for rock resistivity with different matrix resistivity,salt water resistivity levels,and different damage degrees.The results show that all of the matrix resistivity,salt water resistivity,and the degree of rock damage have an impact on the rock resistivity,and the degree of damage has the greatest impact on the rock resistivity.Through regression analysis of the numerical calculation results,a mathematical relationship between the resistivity of rock with randomly distributed fracture damage and the internal parameters of the rock was obtained,the relationship can better characterize the true resistivity of damaged rocks to a certain extent.The use of rock resistivity to calculate the engineering parameters of rock mass has certain randomness,but it can still reflect the degree of damage to the rock mass on the statistical mean.The application of the regression relationship obtained in this article and the discussion of its randomness have positive significance for the grading evaluation of rockdamage degree.

关 键 词：电阻率 随机分布 裂隙岩石 回归分析 

分 类 号：P631[天文地球—地质矿产勘探]