摘要
金属矿物、硫化物和油气资源等探测目标常呈现较强的激发极化特性,使得瞬变电磁信号出现畸变,若忽略激发极化效应往往导致瞬变电磁数据难以拟合甚至出现错误解释。文中基于时域有限体积法,采用Padé级数对Cole-Cole模型进行逼近,实现了含激发极化效应的瞬变电磁三维正演模拟。传统Padé级数中心频率的选取采用定性分析方法,正演结果对频率相关系数的变化较为敏感,限制了其在频率相关系数变化较大区域的应用。文中定量计算了Padé级数逼近过程产生的误差,并基于误差信息提出了中心频率自适应选取算法,解决了这一问题。通过多个模型数值实验,验证了文中算法的计算精度及有效性。最后,分析了极化介质模型与非极化介质模型瞬变电磁响应的特征差异,并对实例模型模拟了瞬变电磁场极化异常体的充放电过程。
The exploration targets such as metallic minerals,sulfides,and oil and gas resources often exhibit a strong induced polarization(IP)effect,which causes distortion of transient electromagnetic(TEM)signals.Neglecting the IP effect frequently leads to difficulties in fitting TEM data and even results in erroneous interpretations.This study employs the time-domain finite volume method(FVM)and approximates the Cole-Cole model by using a Padéseries to achieve 3D forward modeling of the TEM method considering the IP effect.Traditional methods for selecting the central frequency in the Padéseries rely on qualitative analysis,which makes the forward modeling results highly sensitive to changes in the frequency-dependent parameter.This sensitivity limits the application of Padéapproximation in regions with significant variability in the frequency-dependent parameter.To address this limitation,this study quantitatively evaluates the errors introduced during the Padéapproximation process and proposes an adaptive selection algorithm based on error information.Multiple numerical experiments demonstrate the accuracy and effectiveness of the proposed algorithm.Finally,the differences in TEM responses between polarized and non-polarized media models are analyzed,and the charging and discharging processes of polarization anomaly bodies in TEM fields are simulated using an instance model.
作者
杨威
蔡盼盼
李清坤
刘礼煌
胡祥云
刘亚军
YANG Wei;CAI Panpan;LI Qingkun;LIU Lihuang;HU Xiangyun;LIU Yajun(Research Institute of Exploration and Development,SINOPEC Northwest Oilfield Company,Urumqi,Xinjiang 830011,China;School of Geophysics and Geomatics,China University of Geosciences,Wuhan,Hubei 430074,China;Badong National Observation and Research Station of Geohazards,China University of Geosciences,Wuhan,Hubei 430074,China;Hubei Key Laboratory of Resources and Eco-Environment Geology,Hubei Geological Bureau,Wuhan,Hubei 430034,China)
出处
《石油地球物理勘探》
北大核心
2025年第3期794-805,共12页
Oil Geophysical Prospecting
基金
中石化科研项目“超深碳酸盐岩油气藏地震—电磁联合描述技术研究”(P22875)
国家自然科学基金项目“含激电效应的时间域电磁法三维各向异性正反演研究”(42104077)
资源与生态环境地质湖北省重点实验室开放基金资助项目“广域电磁三维反演技术及其在铜绿山矿集区深部找矿中的应用研究”(HBREGKFJJ-202310)
国家自然科学基金项目“冰岛地区综合地球物理研究”(42220104002)
湖北省自然科学基金项目“基于三维探地雷达高速探测的道路病害智能反演方法”(2024AFD417)联合资助。
作者简介
杨威,副研究员,1984年生,2007年获成都理工大学信息工程专业学士学位,2011年获成都理工大学地球探测与信息技术专业硕士学位,2024年获成都理工大学地球探测与信息技术专业博士学位,现就职于中石化西北油田分公司勘探开发研究院,主要从事地震资料处理及地震和电磁方法应用研究;刘亚军,湖北省武汉市洪山区鲁磨路388号中国地质大学(武汉)湖北巴东地质灾害国家野外科学观测研究站,430074。Email:liuyajun@cug.edu.cn。
