Results of a marine controlled-source electromagnetic (CSEM) survey with the use of seafioor receivers are presented. The survey was carried out at the shelf of the Black Sea in 2011. The aim of these measurements was to detect geological objects containing hydrocarbons. The peculiarities of technology are the surface-towed source and the use of both frequency and time domains. Frequency-domain CSEM (geometrical sounding) allows for detecting zones of anomalous resistivity. With the help of the time-domain CSEM (transient electromagnetic sounding) it is possible to evaluate parameters of the induced polarization. Effectiveness of the technology at the sea depths from 100 to 300 m is demonstrated.......

A method for calculating the transient electromagnetic field induced by an isolated closed loop located in the conductive medium when exciting the primary field by an airborne circular transmitting loop is studied. This method is based on the connection of the magnetic flux passing through a closed loop and the current flowing in it. The calculation scheme and the results of comparison to the 3-D finite-element modeling are given. It is shown that the method proposed allows quick and precise calculation of EMF value in the receiver at any position of the field source relative to the closed loop and can be effective in testing for the aero-based and land-based electrical exploration equipment.......

Differential phase parameter (DPP) has been widely and for a long time used in Russian electric exploration for suppression of inductive coupling effect in the frequency domain while using induced polarization (IP) methods. However, its influence on the IP phase is usually ignored and the obtained DPP value is considered to be equal to the phase value, which is correct only in narrow frequency bands where the latter is almost frequency independent. In case of observing the IP phase behavior at a significant number of frequencies this condition is not usually satisfied and the applicability of the method is a subject of a separate discussion. In this paper the mathematical properties of the DPP operator and its distorting effect on the frequency-dependent functions are investigated. Several methods of IP phase curve recovery from DPP curve are proposed.......

This paper summarizes the results of petrophysical studies of the material composition of rocks of the Riphean-Vendian terrigenous deposits in Eastern Siberia. Shows the basic features of deposits: lithological heterogeneity, bedding, assorted, volatility of rocks on the mineralogical density by the inclusion dolomite, anhydrite and magnesite. Has been suggested zeolitization of sandstones deposited in the bottom of oskobinskoy suite. In the studied section the boundary values of the coefficients of porosity are determined to allocation granular reservoirs. The article describes the possibility of using the data density gamma-gamma method to estimate reservoir properties of rocks taking into account the on the separation of lithotypes.......

Based on a standard complex of well logs are calculated statistical parameters that identify epigenetically converted intervals terrigenous reservoirs, the nature and degree of their transformation, and locate low-resistance layers, lowering the resistivity which is due to conductive minerals. Comparison of statistical parameters with the concentration of minerals, identified by laboratory method, showed the correspondence of these parameters mineral composition of sandstone.......