Research on Induced Polarization Effect of Frequency‐Domain Electromagnetic Sounding of Electric Dipole Source

Abstract

The induced polarization (IP) effect on Frequency-domain electromagnetic sounding with electric dipole source is studied in this paper. Firstly, the reasonability of extracting IP information from electrical field Ex is discussed by analyzing the resolution of the electromagnetic field components in frequency-domain electromagnetic sounding with electric dipole source. Then, corresponding theoretical calculation formula and algorithm of frequency electromagnetic sounding when Induced Polarization effect and electromagnetic effects coexist are introduced, and some typical earth models are calculated and corresponding results are analyzed. Finally, some possible methods to extract IP information are put forward. This study not only provides the theoretical basis for extracting IP information from field data, but also can be used to separate Induced Polarization effect from electromagnetic effect.

A time domain induced polarization relaxation time spectrum inversion method based on a damping factor and residual correction

“…When an external electric field is applied at both ends of the pore, ion concentration gradient and polarization potential emerge. After the electric field is removed, the gradient disappears gradually with ion diffusion and the ion concentration comes back to the initial state, forming the polarization potential decay curve (Vinegar and Waxman, 1984;Jiang et al, 1999;Tarasov and Titov, 2007;Guan et al, 2010;Li et al, 2011).…”

Research into the inversion of the induced polarization relaxation time spectrum based on the uniform amplitude sampling method

“…Compared with the NMR logging mode, the IP logging mode has greater probing depth, higher signal-tonoise ratio, and less cost, so it has wider and more favorable application prospects (Titov et al 2002(Titov et al , 2010Wang 2004). The IP logging instrument can obtain the polarization decay potential (Guan et al 2010;Li et al 2011) which contains very rich underground information. The RTS inverted from the IP decay potential can be used to analyze the pore size distribution of the strata, and then to make assessments on the rock permeability, the amount of oil or water storage, and so on (Liu et al 2014a, b;Rezaee et al 2006;Binley et al 2005;Zimmermann et al 2008;Gurin et al 2013;Beckett and Augarde 2013;Li et al 2010).…”