AFTEREFFECTS IN THE TRANSIENT ELECTROMAGNETIC METHOD: INDUCTIVELY INDUCED POLARIZATION
N.O. Kozhevnikov1,2, E.Yu. Antonov1
1Trofimuk Institute of Petroleum Geology and Geophysics, Siberian Branch of the Russian Academy of Sciences, pr. Akademika Koptyuga 3, Novosibirsk, 630090, Russia
2Novosibirsk State University, ul. Pirogova 1, Novosibirsk 630090, Russia
Keywords: Inductively induced polarization, transient electromagnetic method
Abstract
Inductively induced electric polarization (IIP) is one of the aftereffects inherent in the geologic materials and affecting results of the transient electromagnetic method. Its effect on the inductive transient response manifests itself as a nonmonotonic EMF decay, including the polarity reversal. The dependence of IIP on many conditions makes it difficult to study the basic regularities in its manifestation. One of the ways to address this problem is to present the simulation results as a normalized transient response. From the most general point of view, the intensity and time range of the IIP manifestation are controlled by the competition between induction and induced polarization phenomena. Induced polarization manifests itself differently, depending on the transmitter used for the excitation of the ground response. Therefore, when studying polarizable ground, the results of the conventional IP method and those of the TEM method do not always correlate.
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