Analysis of Passive Seismoelectric Measurements in Earth's Noise Fields

Abstract

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.

Study of the Seismoelectric Effect of the Second Kind Using Molecular Sensors

“…As shown in Table 2 , obtained in 2019–2020, the experimental data confirmed the results of the measurements in 2014–2018 [ 27 , 28 , 44 , 45 , 46 , 47 ]. Figure 9 b also shows a curve obtained by solving Equations (1)–(8), according to which the values of the electric field strength E will correspond to the magnitude of the observed SE effect on the day surface.…”

“…Earlier [ 27 , 28 , 46 , 47 ], we have shown, both theoretically and empirically, that the SE effect of the second kind is most pronounced at the edges of the field. This is due to the distribution function of the electric charges along the boundaries of the field, which cause an EM field when exposed to microseismic disturbances.…”

“…This was the first attempt to process data obtained in different years of observation. Based on the experience of [ 27 , 28 , 44 , 45 , 46 , 47 ] on this profile, it can be concluded that the amplitude value of the observed cross-correlation coefficient on the Earth’s surface depends on many factors. Thus, the absolute value of this coefficient cannot be used for the assessment, and, therefore, the shape of the resulting curve is a more important factor.…”