Electroprospecting (electrometry) is a branch of exploratory geophysics. Methods of electrical exploration are based on measuring the parameters of artificially created and natural electromagnetic fields in rocks. Electrical exploration is used in the search and exploration of deposits of metal ores, groundwater, in engineering geology, ecology and archeology.
In electrical exploration, there are now more than fifty different methods and modifications designed both for in-depth research and for the study of the upper part of the incision. Depending on the principle of research, they can be divided into the following groups: resistance methods (DC methods) and electromagnetic methods.
Types of Electrical Survey
Methods of apparent resistances
Apparent resistance methods are based on passing a known direct current in the ground with a pair of electrodes and measuring the voltage caused by this current using another pair of electrodes. Knowing the current and voltage, it is possible to calculate the resistance, and taking into account the configuration of the electrodes, it is possible to establish to which part of the subsurface space this resistance belongs.
Induction methods
The group of methods includes a huge number of different modifications, the essence of which can be described as follows. Under the influence of an alternating electric or magnetic field in the ground due to the phenomenon of magnetic induction, an electromagnetic field arises. Knowing exactly the parameters of the field source, it is possible to measure various electric and magnetic components of the induced field, restoring the parameters of the medium according to them.
Downhole electrical exploration
Borehole electrical exploration is a method of volumetric study of interstitial space, based on the excitation and study of the field both inside the wells and on the surface of the earth, as well as on the electromagnetic transmission of the environment between wells, this includes all options for electrical profiling in wells, methods of induced polarization, natural electric field, including methods of electric charge.