A "SELF-CONSISTENT SOLUTION" METHOD FOR DETERMINING THE ELECTRICAL CONDUCTIVITY IN THE SUBSURFACE REGIONS OF THE EARTH

The assumptions on which the so-called magneto-telluric method to determine the subsurface conductivity of the earth is based are examined and it is shown how the method can be revised to get rid of those assumptions which are not necessarily legitimate. The principle of this revised or generalized magneto-telluric method is that the magnetic and telluric field components which observation can provide over the entire surface of the earth are more than sufficient viewed as boundary conditions to determine the electromagnetic field inside the earth with a prescribed conductivity distribution and, therefore, the extra boundary conditions can be consistent with each other only by the correctly prescribed (or chosen) distribution of electrical conductivity. The purely magnetic method to determine the conductivity, which relies on the assumption that the magnetic field in space above the surface of the earth, is a potential field, is also revised to free it of the assumption which, does not hold true unconditionally.

Download Full-text

On the differential system govering flows in magnetic field with data inLp

International Journal of Mathematics and Mathematical Sciences ◽

10.1155/s0161171298000416 ◽

1998 ◽

Vol 21 (2) ◽

pp. 299-305 ◽

Cited By ~ 3

Author(s):

Fengxin Chen ◽

Ping Wang ◽

Chaoshun Qu

Keyword(s):

Magnetic Field ◽

Initial Data ◽

Boundary Conditions ◽

Differential System ◽

Existence And Uniqueness ◽

Mhd Equations ◽

The Earth ◽

Initial And Boundary Conditions ◽

Time Existence ◽

The Magnetic Field

In this paper we study the system governing flows in the magnetic field within the earth. The system is similar to the magnetohydrodynamic (MHD) equations. For initial data in spaceLp, we obtained the local in time existence and uniqueness ofweak solutions of the system subject to appropriate initial and boundary conditions.

Download Full-text

Using the Carotazh Method to Determine the Electrical Characteristics of the Earth’s Subsoil

International Journal of Theoretical & Computational Physics ◽

10.47485/2767-3901.1006 ◽

2021 ◽

Keyword(s):

Magnetic Field ◽

Electrical Conductivity ◽

Electromagnetic Field ◽

Surface Impedance ◽

Electromagnetic Waves ◽

Dielectric Permeability ◽

Electrical Characteristics ◽

Measuring Systems ◽

The Earth ◽

The Magnetic Field

Logging is a detailed study of the structure of the well incision by descent and ascent of a geophysical probe. It is often used to determine the electrical conductivity of terrestrial depths. To do this, the sides of the well deepen the electrodes, and they are fed into the depths of a constant electric current. However, if you use natural or artificial electromagnetic waves, it becomes possible to determine the dielectric permeability of terrestrial rocks at depth. To do this, the surface impedance is first measured on the surface of the earth, and then by measuring at a certain frequency of the electromagnetic field in the well hole, the electrical conductivity and dielectric permeability of terrestrial rocks are calculated by fairly simple formulas. Such measurements can be carried out by standard measuring systems, adding only a narrow frame with wire winding to measure the magnetic field.

Download Full-text