Frequency domain electromagnetic exploration method for acquiring resistivity based on horizontal electric field and magnetic field

Abstract

The invention discloses a frequency domain electromagnetic exploration method for acquiring resistivity based on a horizontal electric field and a magnetic field. The method comprises the following steps of S1, arranging an observation device, wherein the observation device comprises a transmitter, two power supply electrodes A and B, a measuring point provided with a measuring electrode, and a receiver capable of simultaneously observing the electric field and the magnetic field; S2, enabling the observation device to work normally, receiving an electromagnetic response signal fed back by the measuring point by the measuring equipment, and sending the electromagnetic response signal to a processing device; and S3, the processing device calculating apparent resistivity of different frequencies of the position where the measuring point is located according to the electromagnetic response signal, and the stratum information being obtained through qualitative analysis and quantitative calculation. As the method has no orientation limitation on an electric field and a magnetic field, wide-azimuth electromagnetic ground detection can be realized, and field construction efficiency is greatly improved; and secondly, the apparent resistivity is strictly defined based on an electric field and magnetic field component formula, so the geoelectric information can be accurately reflected, and the influence of the field source emission efficiency on electromagnetic sounding can be eliminated.

Description

technical field [0001] The invention relates to the technical field of electromagnetic prospecting in the field of prospecting geophysics, in particular to a frequency-domain electromagnetic prospecting method based on horizontal electric fields and magnetic fields to obtain resistivity. Background technique [0002] The traditional artificial source electromagnetic method (CSEM) either simplifies the electromagnetic field formula or uses a single component when defining the apparent resistivity. For the controlled source audio frequency magnetotelluric method (CSAMT), the Carnia formula is used to calculate the apparent resistivity, and the high-order term of the electromagnetic field component is discarded, which is only suitable for far-field observations; secondly, two orthogonal electric and magnetic fields need to be strictly measured The weight restricts the efficiency of field construction and causes unnecessary human errors. [0003] For the wide-field electromagne...

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Problems solved by technology

[0003] For wide-field electromagnetic method (WFEM), any single component can be used to obtain apparent resistivity parameters, and it can be measured in a wide area. Its measurement range and exploration depth have greater development than CSAMT, but it is also subject to the influence of field source emission efficiency.

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