Resistivity measurement method based on vertical components of electromagnetic field

Abstract

The present invention discloses a resistivity measurement method based on vertical components of an electromagnetic field, belonging to the fields of earth sciences and physical geography. According to the method, under the excitation of a vertical incident plane to the vertical components of the electromagnetic field, the upper and lower sides of the boundary have inductive charges to cause a discontinuous electric field and changed vertical components of the field, the change appears at the upper and lower sides of the boundary so as to accurately reflect the positions of the upper and lowerboundaries of an object. The [Rho]EH T-inverted definition equation provided by the invention improves the resolution capability for the upper and lower interfaces of an electricity anomalous body due to direct reference of the discontinuity of the electric field on the upper and lower interfaces, and the resolution capability is only related to the electricity contrast ratio and the burying of the anomalous body and is not related to the size of the anomalous body so as to have important meaning for accurate detection of a small anomalous body in a superficial layer and the depth fine detection of the mineral resources in the engineering geophysics. The resistivity measurement method based on vertical components of an electromagnetic field is not better sensitive to the noise response inthe impedance Z than a Cagniard resistivity formula.

Description

technical field [0001] The invention belongs to the fields of earth science and geophysics, and in particular relates to a resistivity measurement method based on the vertical component of an electromagnetic field. Background technique [0002] In the 1920s, French scholars C. Schlumberger and M. Schlumberger (C.&M.Schlumberger) brothers first studied and tested the DC resistivity method, and defined it through the device coefficient and the observed potential and current. Representation of apparent resistivity. The AC resistivity method in the modern sense—Magnetotelluric (MT), uses the observed horizontal electric field and the horizontal magnetic field orthogonal to it to define the resistivity expression, which is called "Carniard resistance". rate”, which laid the theoretical foundation of the magnetotelluric method; at the same time, due to the large detection depth of the magnetotelluric method, it has developed rapidly in practical applications and is widely used in...

AI Technical Summary

Problems solved by technology

It responds obviously to substances with large electrical contrast, large volume, and shallow burial, and it is difficult to identify objects with small electrical contrast or deep burial. This is determined by the inherent defects of the resistivity expression defined by the horizontal component of the electromagnetic field. In the method of observation, the observation area is mainly concentrated in the wave area. The electromagnetic field in the wave area is a plane electromagnetic wave that is approximately vertically incident. perfectly reflect the upper and lower interfaces of inhomogeneous bodies

Images