Active source magnetization-time domain electromagnetic induction polarization multi-effect detection method

Abstract

The invention relates to a deep polymetallic ore accurate electromagnetic detection method, and provides an active source magnetization-time domain electromagnetic induction polarization multi-effect detection method by integrating the conductivity, the charging property and the magnetic complex physical property of polymetallic ore. Active source magnetization is carried out in a long conduction time period, and the magnetic characteristics of a geologic body are obtained by observing a static magnetic field; the induction and polarization magnetic field response are observed at the turn-off time, and geologic body electrical characteristics are obtained; and full-waveform response detection is carried out based on a superconducting electromagnetic observation system, so that the conductivity, polarizability and magnetic susceptibility of the deep polymetallic ore can be synchronously obtained.

Description

Technical Field

[0001] The present invention belongs to the technical field of geophysical exploration, and particularly relates to an active-source magnetization-time domain electromagnetic induction polarization multi-effect detection method. Background Art

[0002] Ferromagnetic minerals and surrounding rocks of polymetallic ores (such as copper and gold ores) contain magnetic particles and will generate a magnetic viscosity effect under the excitation of a magnetic field. During the exploration of polymetallic ores using the time domain electromagnetic method, the alternating electromagnetic field will excite the underground medium to generate induction response, polarization response, and magnetization response. Under the long-time window observation of a high-precision sensor, the receiving system usually collects an induction-polarization-magnetization multi-effect field.

[0003] In recent years, scholars at home and abroad have actively developed new electrical and magnetic detection methods on the basis of traditional methods. The active-source magnetic method induces the magnetization of underground magnetic substances through the magnetic field generated by an artificial source, thereby measuring magnetic anomalies, and has a higher signal-to-noise ratio and detection sensitivity compared with the traditional magnetic method.

[0004] The time domain electromagnetic induction-polarization detection method combines the detection advantages of the electromagnetic method and the induced polarization method, can synchronously obtain the induction and polarization dual responses, and has developed an observation method for the induction-polarization effect based on superconducting sensors, effectively realizing the dual-parameter observation of conductivity and polarization rate at a large depth of 1000-2000 meters, and improving the detection resolution of porous sulfide metal ores. Summary of the Invention

[0005] The purpose of the present invention is to provide an active-source magnetization-time domain electromagnetic induction polarization multi-effect detection method, which combines the active-source magnetic method and the induced polarization method, can effectively excite and detect the induction response, polarization response, and magnetization response, and realize the extraction of multi-parameters of conductivity, polarization rate, and magnetic susceptibility.

[0006] The present invention is implemented as follows:

[0007] An active-source magnetization-time domain electromagnetic induction polarization multi-effect detection method, the method comprising:

[0008] 1) Using an ungrounded loop source as the excitation source, and the transmitting system transmits a bipolar trapezoidal wave with a long conduction time;

[0009] 2) Using a superconducting sensing device to receive and collect the entire transmitting waveform period;

[0010] 3) Using the long conduction time period for active-source magnetization. Since the conduction time is long enough, it is considered that the induction field is completely dissipated in the late conduction period, reaching magnetic saturation and approximating a static magnetic field;

[0011] 4) Superposition of responses of bipolar emission waveforms to separate the residual magnetization effect from the total field, and obtain the magnetic characteristics of geological bodies during the conduction stage by observing the induced magnetization effect;

[0012] 5) Observe the induced and polarized magnetic field responses of transient electromagnetic fields during the off-time to obtain the conductivity and charge-discharge characteristics of geological bodies;

[0013] 6) Synchronously obtain the conductivity, polarizability, and magnetic susceptibility of deep polymetallic ores by processing and interpreting the magnetic field data collected in full waveforms.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: Aiming at the complex physical properties of conductivity, rechargeability, and magnetism of polymetallic ores, as well as the electromagnetic response characteristics of multiple effects of induction, polarization, and magnetization, it can effectively excite multiple effects and extract multiple parameters of conductivity, polarizability, and magnetic susceptibility. Compared with electromagnetic detection methods with single or dual effects, it improves the positioning accuracy of polymetallic ores and reduces the problem of non-uniqueness. Description of the Drawings

[0015] Figure 1 It is a schematic diagram of an active-source magnetization-time domain electromagnetic induction polarization multi-effect detection method Detailed Embodiments

[0016] In order to make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0017] Embodiment

[0018] Combined with Figure 1 As shown, an active-source magnetization-time domain electromagnetic induction polarization multi-effect detection method includes:

[0019] 1) Use an ungrounded loop source as the excitation source, and the emission system emits a bipolar trapezoidal wave with a long conduction time for the current;

[0020] 2) Use a superconducting sensing device to receive and collect the entire emission waveform period;

[0021] 3) Utilize the long conduction time period for active-source magnetization. Since the conduction time is long enough, it is considered that the induced field is completely dissipated in the late stage of conduction, reaching magnetic saturation, and approximating as a static magnetic field;

[0022] 4) Superposition of responses of bipolar emission waveforms to separate the residual magnetization effect from the total field, and obtain the magnetic characteristics of geological bodies during the conduction stage by observing the induced magnetization effect;

[0023] 5) Observe the induced and polarized magnetic field responses of transient electromagnetic fields during the off-time to obtain the conductivity and charge-discharge characteristics of geological bodies;

[0024] 6) By processing and interpreting the full-waveform acquired magnetic field data, synchronously obtain the conductivity, polarizability, and magnetic susceptibility of deep polymetallic ores.

[0025] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. An active source magnetization-time domain electromagnetic induction polarization multi-effect detection method, characterized in that: The method includes: 1) Using an ungrounded return line source as the excitation source, the transmitting system transmits a bipolar trapezoidal wave with a long conduction time; 2) Using superconducting sensor devices to receive and collect the entire transmission waveform period; 3) Use a long conduction period for active source magnetization. Since the conduction time is long enough, the induction field in the late conduction period is completely dissipated and reaches magnetic saturation, which is approximately a static magnetic field. 4) The response superposition of the bipolar transmission waveform separates the residual magnetization effect from the total field, and the magnetic characteristics of the geological body are obtained during the conduction stage by observing the induced magnetization effect; 5) Observe the induction and polarization magnetic field response of transient electromagnetic during the off time to obtain the conductivity and charge-discharge characteristics of the geological body; 6) By processing and interpreting the full-waveform magnetic field data, the electrical conductivity, polarizability and magnetic susceptibility of deep polymetallic ores can be acquired simultaneously.

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