The first experimental measurements of the cross-correlation function (CCF) of the Earth’s seismic and electrical noise were carried out in two areas of the Minusinskoe gas condensate field in 2014 and 2015 using a VPEMPZ-M1 (Shum-6) two-channel geophysical device developed at Siberian Federal University. The Earth’s seismic noise and electrical noise in the frequency range 0.1–20 Hz were received by a geophone and an electric dipole, respectively. In both cases, a productive pool at depths of 1800–2000 m had a maximum CCF value five to seven times higher than the normal background, indicating the occurrence of the seismoelectric effect in passive fields.

The paper deals with the physical fundamentals of the phase geoelectric method of induced polarization (IP) based on the extraction of information from the natural electromagnetic field of the Earth (NEMFE) in the frequency range 0.1–20.0 Hz. Scientific and technical justification is provided for the differential measurement circuit parameters of the NEMFE and the algorithm of processing of the received signals with the calculation of the IP coefficient, assuming the identity of the field characteristics in two receiving lines. The method consists in recording random noise signals from two adjacent receiving electrical dipoles with simultaneous memorizing of the amplitudes and their automatic equalization. Then the difference between the signals is calculated, with subsequent energy normalization. The presented theoretical fundamentals for the calculation of the IP coefficient of the NEMFE and the processing algorithm were tested in laboratory experiments. Under the assumption of the complete identity of the medium beneath the receiving dipoles, the IP coefficient was 0.01–0.03, due to the error in the elemental base of the analog input path. The paper also presents the results of field experiments on the Samson iron deposit in the Republic of Khakassia. The experimental work confirmed the effect of IP on the NEMFE in the anomalous area and showed that the results are consistent with theoretical and laboratory predictions and the data obtained using a KEP-M pulse system. It is concluded that this method can be used to detect productive anomalies and has an advantage of eliminating artificial sources of excitation of geologic sections.

The article considers the observational statistics analysis of seismoelectric effects of the second kind at the Bystryanskoye gas condensate reservoir in Krasnoyarsk Territory. The measurements were carried out by the passive method from 2014 to 2019 on one exploration profile. The authors obtained an averaged profiling curve. Its analysis showed that there exists the repeatability of measurement results, as well as the convergence with the results of mathematical modeling. The collected statistics on the observation points shows the possibility of this method application in carrying out industrial field work in conjunction with the standard seismic exploration.

This work analyzes repeated observations of seismoelectric effects at Novomikhailovskoe gas condensate deposit (Khakassia, Russia) with the occurrence depth more than 2,500 m and plotting of detailed profile with the distance between observation points of 200 m, as well as acquisition of statistic data and verification of the previous results obtained by the same method. The electromagnetic wave reflected from productive stratum has been quantitatively estimated in the frequency range of 0.1-20 Hz from the depth up to 2,500 m. It has been demonstrated that the field level at Earth surface corresponds to recorded values of the Earth's magnetotelluric field. The data are presented confirming that the deposit edge is marked by a maximum of cross-correlation function equaling to 0.4, whereas there are no maximums of cross-correlation function in the deposit center. Therefore, it is proved that the results obtained by passive seismoelectric method at one and the same deposit profile are repeated at various observation times.

The main objective of this work is the comparison of experimental observations by means of the passive seismoelectric method at Bystryanskaya gas condensate field (Krasnoyarsk krai) with the profile acquired by the conventional seismic survey as well as the analysis of the influence of atmospheric electricity on measurements. This article simulates and estimates the influence of atmospheric electricity on the natural Earth's electromagnetic field using calculated data. Measurements by the passive seismoelectric method were carried out in July 2018 using three-electrode facility comprised of a grounded electric dipole with the length of 200 m and a seismic receiver installed at the dipole center. Fields were recorded in the frequency range of 0.1-20 Hz. According to the data of exploratory drilling, the productive formation was at the depth of 2-2.5 km, which corresponded to the signal delay of 1.2-1.6 s. The boundaries of productive formation were detected by the seismoelectric method: 0.15-0.25 of a maximum of cross-correlation function at signal-to-noise ratio equaling to 4.