【作者】 王鹏；

【导师】 钱家忠； 刘冬节；

【作者基本信息】 合肥工业大学 ， 地质工程（专业学位）， 2021， 硕士

【摘要】 井中磁测是地面磁测在地下钻孔中的延伸,是一种基于研究各种岩矿石的磁性差异及由此引起的地磁场变化的井中物探方法,相比于地面磁测,其探头更靠近深部矿产,同时远离地表的各种电磁干扰,克服了地面磁测对来自深部磁性体的磁异常信息反应比较弱、反演解释的纵向分辨率比较差的问题。近年来,近地表勘探程度在不断增加,矿床在近地表被发现的概率在减小,矿产勘探工作也在逐步向深部转移,井中磁测在深部含磁性矿床的勘探中的作用也越来越重要。本文从井中磁测的基础理论入手,研究了球体和厚板状体模型的磁场解析模型,分析了球体和厚板状体模型在不同模型参数的条件下的磁场分布及其变化规律,并结合庐江县黄寅冲矿区井中磁测项目实际进行研究,得到主要成果与结论如下:(1)基于井中磁测的基础理论,推导了球体和厚板状体在地下半空间内的磁场解析解;(2)利用解析式分析了球体模型在不同距离、方位的钻孔中和球体不同磁化方向时的磁场分布特征;分析了厚板状体模型在不同距离、方位的钻孔中,厚板状体不同磁化方向、倾斜方向时,钻孔穿过厚板状体时和钻孔有底部异常时的磁场特征,总结了其变化规律。(3)应用总结的规律并结合磁场的水平分量模差对黄寅冲矿区的3个钻孔分别详细进行反演解释,同时结合地面磁测资料进行综合分析,确定了磁性体的空间展布状态。更多还原

【Abstract】 Magnetic well-logging is an extension of surface magnetic survey in underground boreholes.It is a borehole geophysical method based on the study of magnetic differences of various rocks and ores and the resulting changes of geomagnetic field.Compared with surface magnetic survey,its probe is closer to deep minerals,and at the same time,it is far away from the surface of various electromagnetic interference,which overcomes the problems of weak response of surface magnetic survey to magnetic anomaly information from deep magnetic body and poor vertical resolution of inversion interpretation.In recent years,the degree of near surface exploration is increasing,the probability of deposits being found near the surface is decreasing,mineral exploration work is gradually transferring to the deep,and the role of borehole magnetic survey in the exploration of deep magnetic deposits is becoming more and more important.Starting from the basic theory of borehole magnetic survey,this paper studies the analytical model of magnetic field of sphere and thick plate model,analyzes the magnetic field distribution and variation law of sphere and thick plate model under the condition of different model parameters,and studies the actual borehole magnetic survey project in Huangyinchong mining area of Lujiang County(1)Based on the basic theory of borehole magnetic survey,the analytical solution of magnetic field of sphere and thick plate in underground half space is derived;(2)The magnetic field distribution characteristics of the sphere model in different distances and directions of drilling and the sphere in different magnetization directions are analyzed by using the analytical formula;the magnetic field characteristics of the thick plate model in different distances and directions of drilling,when the thick plate has different magnetization directions and inclination directions,when the drilling passes through the thick plate and when the drilling has bottom anomaly are analyzed,and the variation rules are summarized.(3)The three boreholes in Huangyinchong mining area are inversed and interpreted in detail by using the summarized rules and combined with the difference of the modulus of the horizontal component.At the same time,the spatial distribution state of the magnetic body is determined by comprehensive analysis of the surface magnetic survey data.更多还原