拟地震法电磁波场有限元法正演模型

来源期刊：中南大学学报(自然科学版)1992年第6期

论文作者：沈飚 何继善 鲍光淑

文章页码：633 - 638

关键词：有限元法; 电场视剖面; 地震学

Key words：finite element method; EM psudo-section; seismology

摘    要：在电法勘探正演模拟中,利用有限元法提出了电磁波在二维电阻率介质模型中的传播特征.我们将电磁波波动方程与声波波动方程类比,运用适当的近似,取等效方程中相同的主要项,利用适当的边界条件,则电磁波场问题可化为类似于地震波场问题,从而可用地震资料处理技术中的任何方法去完成.我们选用的是波动方程有限元方法.计算可在频域也可在时域进行去模拟二维电阻率分布的响应即电场视剖面.实例表明:正演结果所得到的二维电阻率成像剖面与实际的二维电阻率分布完全相吻合.结果表明利用有限元进行电阻率成像是切实可行的.

Abstract: In this paper, we show forward modeling propagation character of EM wavein 2-D resistivity media using finite element method. We draw a parallel betweenthe EM and acoustic wave equation, and use appropriate approximations andidentification terms that are equivalent and appropriate boundary condition.ThusEM wave can be simplified to seismic wave field, and EM data can be processedusing any of the methods originally developed for processing seismic data. Themethod we chosed here is finite element methord of wave equation. The algorithm is implemented in the frequency domain or time domain inorder to model EM responses of 2-D resistivity distributions that are pseudosection.The practical results show that imaging section in 2-D resistivity media using forward method coincides with actual 2-D resistivity distribuutions. The conception of imaging resistivity using finite element method is shown to be feasible.