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The article describes results of electromagnetic TEM and sTEM exploration in the settings of the Arctic zone of Western Siberia. The research consisted of a separate study of the upper and the lower parts of the section, which made it possible to obtain a detailed geoelectric model in the depth interval from the first meters to 5 km. As a result of the research, the latest data on the distribution and thickness of permafrost rocks, deep channels of hydrocarbon migration, and prospects for the oil and gas potential of the study area were obtained. The boundary of the cryolithozone distribution according to the sTEM is presumably located at a depth of about 450-470 m. In addition, for the first time, according to the data of the sTEM, the prerequisites for the presence of gas hydrate deposits in the shallow section are revealed. According to EM data, the geoelectric structure of the sedimentary rocks to a depth of 5 km was estimated by the method of deep 3D TEM, and promising oil and gas bearing objects in the sedimentary cover of the study area were identified.

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The article presents the results of studying the internal structures of platform fault zones with the use of a new tectonophysical approach to processing and interpretation of electrical exploration data obtained by the transient elec‐ tromagnetic method in the near field zone (TEM). In the study of the central part of the Kovykta gas condensate field (East Siberia, Russia), we applied the ideas of tectonophysics envisaging three stages of fault formation, which determine the three‐membered transverse zoning of a fully formed fault zone. Each subzone is characterized by a certain level of rock disturbance and corresponding electrical conductivity. Based on the analysis of electrical conductivity values, the boundaries can be determined between locations differing by the degrees of rock disturbance of the sedimentary stra‐ tum. Using a map of this parameter, it becomes possible to generally establish the boundaries of fault zones and specify internal subzones. The new approach was applied to assess the electrical conductivity of the reservoirs of the Kovykta field. It is established that there are several zones of faulting in the sedimentary stratum, which have not reached a final stage of development when a single fault plane is formed. Currently, these are zones of increased fracturing and dense occurrence of second‐order ruptures that are typical of platform settings due to their relatively weak tectonic activity. The zones are structurally non‐uniform, as evidenced by rheological layering of the sedimentary cover in the vertical cross‐section. A 3D electrical conductivity model of the largest fault zone in the study area shows alternating segments with more or less developed internal structures. Such segments are confined to layers that differ with respect to frac‐ turing. Exploration and development of hydrocarbon deposits can benefit from 3D modeling of large fault zones with the use of the tectonophysical approach for processing and interpretation of the TEM data. The models can provide addition‐ al arguments for improved decision making about locations for trouble‐free well drilling, as well as for selecting more effective methods for drilling sedimentary strata composed of complex horizontal layers.