井间电磁波层析成像中的高精度时间域正演计算

林树海; 赵立英

井间电磁波层析成像中的高精度时间域正演计算

林树海^{1, 2, 3,},
赵立英⁴

1.
地质过程与矿产资源国家重点实验室和地下信息探测技术与仪器教育部重点实验室, 北京 100083
2.
中国地质大学地球物理与信息技术学院, 北京 100083
3.
中国科学院地质与地球物理研究所, 北京 100029
4.
北京科技大学应用科学学院, 北京 100083

基金项目:

北京市重点学科“地球探测与信息技术” XK104910598

详细信息

作者简介:
林树海（1964-）,男,副研究员,主要从事地球物理测井、电磁法勘探研究．E-mail：lin_shuhai@163.com

中图分类号: P631.3
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出版历程
- 收稿日期: 2007-04-12
- 刊出日期: 2007-07-25

High Precision Time Domain Forward Modeling for Crosshole Electromagnetic Tomography

LIN Shu-hai^{1, 2, 3
,},
ZHAO Li-ying⁴

1.
State Key Laboratory of Geological Processes and Mineral Resources; Geo-detection Laboratory of the Ministry of Education, Beijing 100083, China
2.
School of Geophysics and Inf ormation Technology, China University of Geosciences, Beij ing 100083, China
3.
Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China
4.
School of Applied Science, University of Science and Technology Beijing, Beijing 100083, China

摘要

摘要: 为提高井间电磁波层析成像的分辨率, 正演计算中需保持较高的计算精度.本文正演计算中采用时间域伪谱(PSTD) 法模拟井间电磁波的传播.该算法在时间域有限差分(FDTD) 法的基础上采用快速傅立叶变换(FFT) 计算麦克斯韦方程中的空间导数.该算法除了具备时间域有限差分法的优点外, 在计算条件完全相同的情况下, 计算精度明显高于时间域有限差分法.时间域伪谱法的正演计算为井间电磁波高分辨率层析成像奠定了重要基础.
- 时间域有限差分 /
- 时间域伪谱法 /
- 正演计算 /
- 层析成像
Abstract: In order to improve the resolution of crosshole electromagnetic tomography, high precision of forward modeling is necessary. A pseudo-spectral time domain (PSTD) forward modeling was used to simulate electromagnetic wave propagation between two boreholes. The PSTD algorithm is based on finite difference time domain (FDTD) method and employs fast Fourier transform (FFT) to calculate spatial derivatives in Maxwell′s equations. Besides having the strongpoints of FDTD method, PSTD algorithm also demonstrates higher calculation precision than FDTD method under the same calculation condition. The PSTD forward modeling has laid important foundation of crosshole electromagnetic high-resolution tomography.
- finite difference time domain method /
- pseudo-spectral time domain algorithm /
- forward modeling /
- tomography

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图 1 模型

Fig. 1. Model

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图 2 发射器位于井中5 m位置时电场的快照

Fig. 2. Snapshot of electric field when transmitter is at 5 m in hole

a. PSTD, t=70 ns; b. PSTD, t=140 ns; c. PSTD, t=210 ns; d. FDTD, t=70 ns; e. FDTD, t=140 ns; f. FDTD, t=210 ns

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图 3 发射器位于井中5 m位置时阵列接受器的波形图

Fig. 3. Waveform of array receivers when transmitter is at 5 m in hole

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图 4 发射器位于井中12 m位置时电场的快照

Fig. 4. Snapshot of electric field when transmitter is at 12 m in hole

a. PSTD, t=70ns; b. PSTD, t=140ns; c. PSTD, t=210ns; d. FDTD, t=70ns; e. FDTD, t=140ns; f. FDTD, t= 210ns

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图 5 发射器位于井中12 m位置时阵列接受器的波形图

Fig. 5. Waveform of array receivers when transmitter is at 12 m in hole

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参考文献(13)

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