3D controlled-source electromagnetic modeling in anisotropic medium using edge-based finite element method

TLDR: The method uses the edge-based vector basis functions, which automatically enforce the divergence free conditions for electric and magnetic fields, which is effective in modeling the seafloor bathymetry using hexahedral mesh.

About: This article is published in Computers & Geosciences.The article was published on 2014-12-01 and is currently open access. It has received 85 citations till now. The article focuses on the topics: Mixed finite element method & Extended finite element method.

Figures

Fig. 5. A comparison between the finite element result and the 1D semi-analytical solution for the secondary magnetic field with a frequency of 0.5 Hz on the seafloor. The upper panel shows a comparison for the x component of secondary magnetic field at = −y 50 m; the middle panel shows a comparison for the y component of secondary magnetic field at y¼0; the lower panel shows a comparison for the z component of secondary magnetic field at = −y 50 m.

Fig. 8. Plane view of the grid used for the model of the off-shore HC reservoir. The blue area indicates the reservoir and the red star represents the location of a dipole source. (For interpretation of the references to color in this figure caption, the reader is referred to the web version of this paper.)

Fig. 6. 3D view of a model of the off-shore HC reservoir. The resistivity is shown in logarithmic scale.

Fig. 7. Vertical section at y¼0 of the grid used for the model of the off-shore HC reservoir. The blue area indicates the reservoir and the red star represents the location of a dipole source. (For interpretation of the references to color in this figure caption, the reader is referred to the web version of this paper.)

Fig. 28. Bathymetry model with the HC reservoir. A comparison of the x component of the anomalous electric field computed using the finite element (red circles) and integral equation (blue line) methods at y¼0 along the sea floor for a frequency of 1 Hz. (For interpretation of the references to color in this figure caption, the reader is referred to the web version of this paper.)

Fig. 27. X–Z section of the hexahedral grid for bathymetry model with a reservoir. The red star indicates the location of the dipole source oriented in the x direction. (For interpretation of the references to color in this figure caption, the reader is referred to the web version of this paper.)

Frequently asked questions

Q1. What have the authors contributed in "3d controlled-source electromagnetic modeling in anisotropic medium using edge-based finite element method" ?

This paper presents a linear edge-based finite element method for numerical modeling of 3D controlledsource electromagnetic data in an anisotropic conductive medium. The authors use a nonuniform rectangular mesh in order to capture the rapid change of diffusive electromagnetic field within the regions of anomalous conductivity and close to the location of the source. 

Q2. What are the future works in "3d controlled-source electromagnetic modeling in anisotropic medium using edge-based finite element method" ?

Future work will be aimed at the implementation of the high order finite elements and at the use of the unstructured tetrahedral and hexahedron meshes to include seafloor bathymetry and complex geoelectrical structures in the modeling of the MCSEM data.