三维张量CSAMT响应特征研究

doi:10.19657/j.geoscience.1000-8527.2022.038

现代地质 ›› 2023, Vol. 37 ›› Issue (01): 84-89.DOI: 10.19657/j.geoscience.1000-8527.2022.038

三维张量CSAMT响应特征研究

刘晓¹(), 宋双林², 谭捍东³, 俞飞洋¹, 王莞辉¹, 鄢禹军¹, 雷祥¹

1.南昌工程学院水利与生态工程学院,江西南昌 330099
2.中煤科工集团沈阳研究院有限公司,辽宁抚顺 113122
3.中国地质大学(北京)地球物理与信息技术学院,北京 100083

收稿日期:2021-10-07 修回日期:2022-12-12 出版日期:2023-02-10 发布日期:2023-03-20
作者简介:刘晓,男,讲师,1987年出生,地质工程专业,主要从事电磁法数值模拟教学与研究工作。Email:friendat2010@163.com。
基金资助:
江西省自然科学基金资助项目(20212BAB213023);2020年江西省大学生创新创业训练计划项目(S202011319012)

Response Characteristics of 3D Tensor CSAMT

LIU Xiao¹(), SONG Shuanglin², TAN Handong³, YU Feiyang¹, WANG Wanhui¹, YAN Yujun¹, LEI Xiang¹

1. School of Water conservancy and ecological engineering, Nanchang Institute of Technology, Nanchang, Jiangxi 330099, China
2. Shenyang Research Institute CCTEG, Fushun, Liaoning 113122, China
3. School of Geophysics and Information Technology, China University of Geosciences, Beijing 100083, China

Received:2021-10-07 Revised:2022-12-12 Online:2023-02-10 Published:2023-03-20

摘要/Abstract

摘要：

张量CSAMT(可控源音频大地电磁法)能完整地描述三维的地电信息,更适应复杂地质条件下的地质勘探。采用将总场分解为一次场和二次场的策略,用差分近似微分形成大型线性方程组,通过解方程组得到张量CSAMT三维正演结果。通过计算低阻和高阻目标体的响应,发现卡尼亚视电阻率和视阻抗相位对低阻体表现为低值异常,对高阻体表现为高值异常,视阻抗相位达到极值时的频率比视电阻率达到极值时的频率要高。张量CSAMT对低阻体比高阻体更灵敏,在同样条件下,高阻体的异常区位置相比于低阻体会上移。某工区的勘察案例表明,根据卡尼亚视电阻率异常能定性地判断地下异常体的存在,为解决地质类问题提供了依据。本研究为张量CSAMT三维反演提供了基础。

关键词: 有限差分法, 张量CSAMT, 正演响应

Abstract:

Tensor CSAMT can fully describe three-dimensional (3D) geoelectric information, and is more suitable for geological exploration under complex geological conditions. Strategy of decomposing the total field into primary and secondary field is adopted here, and the large-scale linear equations are formed by different approximate differentiation. The 3D forward modeling results of tensor CSAMT are obtained according to these equations. By calculating the response of low-resistivity and high-resistivity targets, the Kania apparent resistivity and apparent impedance phase show low and high anomaly for low-resistivity and high-resistivity body, respectively. The frequency of which the apparent impedance phase reaches the extreme value is higher than that when the apparent resistivity reaches the extreme value. Tensor CSAMT is more sensitive to low-resistivity body than to high-resistivity body. Under the same condition, the abnormal area position of high-resistivity body moves upward compared with low-resistivity body. A survey case in the study area shows that the underground abnormal body can be qualitatively judged via the Kania apparent resistivity anomaly, which facilitates geological problem solving. This study provides a basis for tensor CSAMT 3D inversion.

Key words: finite difference method, tensor CSAMT, forward response

中图分类号:

P631.3

刘晓, 宋双林, 谭捍东, 俞飞洋, 王莞辉, 鄢禹军, 雷祥. 三维张量CSAMT响应特征研究[J]. 现代地质, 2023, 37(01): 84-89.

LIU Xiao, SONG Shuanglin, TAN Handong, YU Feiyang, WANG Wanhui, YAN Yujun, LEI Xiang. Response Characteristics of 3D Tensor CSAMT[J]. Geoscience, 2023, 37(01): 84-89.

图/表 8

图1 Yee氏网格空间采样

Fig.1 Spatial sampling of Yee’s grid

图2 源的激发和接收示意图

Fig.2 Sketch diagram of the source excitation and reception

图3 组合体模型示意图

Fig.3 Schematic diagram of the combined model

图4 组合体的卡尼亚视电阻率变化曲线和拟等值线图

Fig.4 Variation curve and pseudo contour map of Kania apparent resistivity for the combined model

图5 组合体的视阻抗相位变化曲线和拟等值线图

Fig.5 Variation curve and pseudo contour map of impedance phase for the combined model

图6 实测数据的卡尼亚视电阻率拟等值线图

Fig.6 Pseudo contour map of Kania apparent resistivity for the measured data

图7 实测地质剖面图[14]

Fig.7 Surveyed geological cross-section [14]

图8 实测地质剖面的卡尼亚视电阻率拟等值线图

Fig.8 Pseudo contour map of Kania apparent resistivity for the surveyed geological cross-section

参考文献 18

[1]	杨震, 周美霞. 可控源音频大地电磁法在个旧西区深部地质结构探测中的应用[J]. 科学技术与工程, 2020, 20(26): 10605-10610.
[2]	柯柏林. 北京市平原区北部孙河断裂的地热地质特征[J]. 现代地质, 2009, 23(1):43-48.
[3]	何柯, 赵远程, 李建华, 等. 砂岩型铀矿地浸开采过程中电法勘查技术的应用[J]. 现代地质, 2018, 32(4):851-862.
[4]	CALDWELL G T, BIBBY M H, BROWN C. Controlled source apparent resistivity tensors and their relationship to the magnetotelluric impedance tensor[J]. Geophysical Journal International, 2002, 151: 755-770. DOI URL
[5]	LI X B, PEDERSEN L B. Controlled source tensor magnetotellurics[J]. Geophysics, 1991, 56(9): 1456-1461. DOI URL
[6]	BOERNER D E, WRIGHT J A, THURLOW J G, et al. Tensor CSAMT studies at the Buchans Mine in Central Newfoundland[J]. Geophysics, 1993, 58(1): 12-19. DOI URL
[7]	胡英才, 李桐林, 范翠松, 等. 基于矢量有限元法的三维张量CSAMT正演模拟[J]. 应用地球物理, 2015, 12(1):35-46.
[8]	谢茂笔, 谭捍东, 王堃鹏, 等. 可控源音频大地电磁法三维张量阻抗响应特征研究[J]. 地球物理学进展, 2017, 32(2): 522-530.
[9]	张超, 陈大磊, 王阳, 等. 层状介质下张量CSAMT最小收发距研究[J]. 物探与化探, 2020, 44(1):156-164.
[10]	王一鸣, 张国鸿, 尤淼, 等. 用正演方法模拟张量CSAMT法的场源效应[J]. 物探化探计算技术, 2018, 40(1):82-88.
[11]	刘志新, 薛国强, 张林波. 张量CSAMT有效观测区域模拟对比分析[J]. 地球物理学报, 2017, 60(8):3278-3287.
[12]	邱长凯, 殷长春, 刘云鹤, 等. 任意各向异性介质中三维可控源音频大地电磁正演模拟[J]. 地球物理学报, 2018, 61(8):3488-3498.
[13]	WANG T, WANG K P, TAN H D. Forward modeling and inversion of tensor CSAMT in 3D anisotropic media[J]. Applied Geophysics, 2017, 14(4): 590-605,623. DOI
[14]	WANG K P, TAN H D, LIN C H, et al. Three-dimensional tensor controlled-source audio-frequency magnetotelluric inversion using LBFGS[J]. Exploration Geophysics, 2018, 49(3):268-284. DOI URL
[15]	钟苏美, 林昌洪, 谢裕春. 起伏地形下可控源音频大地电磁三维数值模拟[J]. 现代地质, 2018, 32(2):398-405.
[16]	谭捍东, 魏文博, 邓明, 等. 大地电磁法张量阻抗通用计算公式[J]. 石油地球物理勘探, 2004, 39(1):113-116.
[17]	刘晓, 汪茂, 陈炳贵. 基于主轴各向异性介质的三维张量CSAMT正演模拟[J]. 地球物理学进展, 2021, 36(3):1095-1102.
[18]	李金铭. 地电场与电法勘探[M]. 北京: 地质出版社, 2007:320.

三维张量CSAMT响应特征研究

Response Characteristics of 3D Tensor CSAMT

RichHTML

PDF (PC)

可视化

摘要/Abstract

引用本文

使用本文

图/表 8

参考文献 18

相关文章 1

编辑推荐

Metrics

本文评价