Body edge delineation in 2D DC resistivity imaging using differential method

Padjadjaran Earth Dialogues: International Symposium on Geophysical Issues

Susanto, Kusnahadi^1 ; Bahari, Mohammad Fitrah^2

Geophysics Program Study, Universitas Padjadjaran, Indonesia^1

Physics Program Study, Universitas Padjadjaran, Indonesia^2

关键词: Contour image;    Dc resistivity;    Differential methods;    First-order differentials;    Laplace operator;    Second orders;    Slicing process;    Wave numbers;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/29/1/012010/pdf
DOI  :  10.1088/1755-1315/29/1/012010

来源: IOP

【 摘 要 】

DC resistivity is widely used to identify the kind of rock and the lithology contact. However, the image resulting from resistivity processing is shown in a contour image. There is be a problem to interpret where the edge of body location is. This study uses differential method to delineate the edge of body in DC resistivity contour. This method was applied to the boundary between gravel and underlying clay layer. The first and the second order differential method is applied to the delineation of lithology contact. The profiling curve has to be sliced and extracted from the resistivity contour before the differential method can be used. The spectral analysis shows the frequency and wavenumber of the profiling curve used to make gridding. The slicing process was conducted horizontally and vertically in order to get the mesh size which will be used in the differential method. The second order differential, the Laplace operator, is able to show the edge of body more clearly than the first order differential and shows the contact between gravel and clay.