Artificial source multi-polarization electromagnetic sounding method and system

Abstract

The invention discloses an artificial source multi-polarization electromagnetic sounding method. The method comprises the following steps: acquiring data information of a target detection area; arranging a long-polar-distance power supply field source and a short-polar-distance power supply field source, and setting parameters of the power supply field sources; setting the arrangement range of the measuring points; working models of the short-polar-distance power supply field source and the long-polar-distance power supply field source are set, and corresponding observation is carried out on set measuring points; electromagnetic sounding information is calculated, and artificial source multi-polarization electromagnetic sounding is completed. The invention also discloses a system for realizing the artificial source multi-polarization electromagnetic sounding method. According to the artificial source multi-polarization electromagnetic sounding method, the power supply field source with the long polar distance and the short polar distance is arranged, multiple parameters such as resistivity, magnetic conductivity and polarizability are observed and extracted, multi-parameter comprehensive analysis is carried out, artificial source multi-polarization electromagnetic sounding is achieved, and the artificial source multi-polarization electromagnetic sounding method is high in reliability, good in accuracy and wide in application range.

Description

Technical Field

[0001] The invention belongs to the field of geophysical exploration, and in particular relates to an artificial source multipolarization electromagnetic sounding method and system. Background Art

[0002] In the field of geophysical exploration, traditional artificial source electromagnetic methods include wide-area electromagnetic method, controlled source magnetotelluric method, transient electromagnetic method, etc. These methods mainly analyze the resistivity changes of the underground by observing the electromagnetic field, so as to achieve the purpose of target detection; moreover, such schemes generally do not consider the polarization effect and magnetization effect of the earth. Therefore, when the polarization effect and magnetization effect of the target are not obvious, such schemes have better application effects.

[0003] However, when searching for sulfide ores or water-rich anomalies, the polarization effect of the target is very obvious; similarly, when searching for magnetic minerals and magnetic rock bodies, the magnetization effect of the target is also very obvious. Therefore, in such cases, continuing to use existing solutions, such as wide-field electromagnetic method, controlled source magnetotelluric method, transient electromagnetic method, etc., will inevitably lead to problems of poor reliability and poor accuracy. Summary of the invention

[0004] One of the purposes of the present invention is to provide an artificial source multi-polarization electromagnetic sounding method with high reliability, good accuracy and wide application range.

[0005] A second object of the present invention is to provide a system for implementing the artificial source multi-polarization electromagnetic sounding method.

[0006] The artificial source multi-polarization electromagnetic sounding method provided by the present invention comprises the following steps:

[0007] S1. Obtain data information of the target detection area;

[0008] S2. Arrange the long-pole-distance power supply source and the short-pole-distance power supply source according to the data information obtained in step S1, and set the parameters of the power supply source;

[0009] S3. Set the layout range of the measuring points;

[0010] S4. Setting the working model of the short-distance power supply source and the long-distance power supply source, and performing corresponding observations at the set measuring points;

[0011] S5. Calculate electromagnetic sounding information based on the observation information obtained in step S4 to complete artificial source multi-polarization electromagnetic sounding.

[0012] The step S1 of acquiring data information of the target detection area specifically includes the following steps:

[0013] Acquire data information of the target detection area; the data information includes the distribution range of the measurement lines, the distribution range of the measurement points, the maximum depth to be measured and the data information of the object to be measured.

[0014] The step S2 of arranging the long-pole-distance power supply source and the short-pole-distance power supply source according to the data information obtained in the step S1 and setting the parameters of the power supply source specifically includes the following steps:

[0015] Arrange the long-pole-distance power supply source and the short-pole-distance power supply source according to the data information obtained in step S1;

[0016] Among them, the value of the short pole distance is 3 to 5 times the maximum detection depth; the value of the long pole distance is 2 times the short pole distance;

[0017] The current waveforms of the long-pole-distance power supply source and the short-pole-distance power supply source are both set to bipolar square waves;

[0018] During measurement, the power supply wire and the measuring wire must be separated and laid at a set distance. The set distance is at least

[0019] The step S3 of setting the arrangement range of the measuring points specifically includes the following steps:

[0020] Set the measurement point layout range to: the middle of the short pole distance range, and short pole distance in the middle Both sides of the range within the range.

[0021] The step S4 of setting the working model of the short-distance power supply source and the long-distance power supply source and performing corresponding observations at the set measuring points specifically includes the following steps:

[0022] The short-distance power supply source is turned on, while the long-distance power supply source is turned off. The receiver is synchronized with the transmitter, and the axial electric field E is observed at each measuring point in turn. x Equatorial magnetic field H y ;

[0023] The short-distance power supply source is turned off, while the long-distance power supply source is turned on. The receiver is synchronized with the transmitter, and the axial electric field E is observed at each measuring point in turn. x Equatorial magnetic field H y ;

[0024] The axial direction is parallel to the line source direction, and the equatorial direction is perpendicular to the line source direction.

[0025] The step S5 of calculating electromagnetic sounding information based on the observation information obtained in step S4 to complete artificial source multi-polarization electromagnetic sounding includes the following steps:

[0026] Based on the observed electromagnetic field, the apparent resistivity, polarizability and magnetic permeability corresponding to different times are calculated;

[0027] According to the apparent depth corresponding to different times, the resistivity, polarizability and magnetic permeability at different depths are obtained by inversion calculation.

[0028] The step S5 specifically includes the following steps:

[0029] (1) Assume that the earth resistivity is ρ and the conductivity is σ The polarizability is m; the electric field in the x direction and the magnetic field in the y direction are observed at the measuring point P(x,y);

[0030] (2) When the short-distance power supply source is working and the long-distance power supply source is turned off, the power supply current amplitude is I, then

[0031] The x-component of the electric field during the power supply platform period Expressed as

[0032] Y-component of magnetic field during power supply platform period Expressed as Where A and B are the grounding points of the short power supply electrode, the center point of AB is the coordinate origin O, L is half of the power supply electrode distance AB, P is the observation point with coordinates (x, y); θ is ∠PAB and is ∠PBA and AP is the distance between the observation point and the power supply point A, and BP is the distance between the observation point and the power supply point B, and

[0033] The power supply platform period excites the underground polarized geological body, and then the power is cut off, and the polarized electric field that decays over time is measured. and polarization magnetic field Then get

[0034] Electromagnetic television polarization

[0035] Magnetic Induction Television Polarization

[0036] Laser TV Depth where D is the maximum detectable depth associated with the short supply electrode spacing 2L and N is a positive integer and N∈[4,10], t is the delay corresponding to the moment when the shutdown starts to be 0, T on is the duration of the supply current;

[0037] (3) When the short-distance power supply source is turned off and the long-distance power supply source is working, the transient induced electric field e that decays with time is observed at the moment of power disconnection. x(t) and the transient induced magnetic field h that decays with time y (t), then

[0038] when When T t is the set threshold, then the calculation is

[0039] Magnetic permeability μ s for

[0040] Resistivity ρ s for

[0041] TEM depth of view for Where t is the delay corresponding to the time when the shutdown starts at 0;

[0042] (4) Based on the data obtained in steps (2) and (3), the resistivity, permeability and polarizability at different depths are inverted.

[0043] The present invention also provides a system for implementing the artificial source multi-polarization electromagnetic sounding method, comprising a data acquisition module, a field source arrangement module, a measuring point arrangement module, an observation module and an electromagnetic sounding module; the data acquisition module, the field source arrangement module, the measuring point arrangement module, the observation module and the electromagnetic sounding module are connected in series in sequence; the data acquisition module is used to acquire data information of the target detection area, and upload the data information to the field source arrangement module; the field source arrangement module is used to arrange long-pole-distance power supply field sources and short-pole-distance power supply field sources according to the received data information and the acquired data information, and set the parameters of the power supply field sources, and upload the data information to the measuring point arrangement module; the measuring point arrangement module is used to set the arrangement range of the measuring points according to the received data information, and upload the data information to the observation module; the observation module is used to set the working models of the short-pole-distance power supply field sources and the long-pole-distance power supply field sources according to the received data information, and perform corresponding observations at the set measuring points, and upload the data information to the electromagnetic sounding module; the electromagnetic sounding module is used to calculate the electromagnetic sounding information according to the received data information and the obtained observation information, and complete the artificial source multi-polarization electromagnetic sounding.

[0044] The artificial source multi-polarization electromagnetic sounding method and system provided by the present invention observes and extracts multiple parameters such as resistivity, permeability, polarizability, etc. through the arrangement of long and short pole-spacing power supply field sources, and performs multi-parameter comprehensive analysis, which not only realizes artificial source multi-polarization electromagnetic sounding, but also has high reliability, good accuracy and a wide range of applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 The figure is a schematic diagram of the method flow of the present invention.

[0046] Figure 2 This is the first schematic diagram of the distribution of long and short pole spacing power supply lines in the method of the present invention.

[0047] Figure 3 This is a second schematic diagram of the distribution of long and short pole spacing power supply lines in the method of the present invention.

[0048] Figure 4 Schematic diagram of the observed electromagnetic field distribution of the method of the present invention.

[0049] Figure 5 Schematic diagram of the functional modules of the system of the present invention. DETAILED DESCRIPTION

[0050] like Figure 1 The method flow chart of the method of the present invention is shown as follows: the artificial source multi-polarization electromagnetic sounding method disclosed in the present invention comprises the following steps:

[0051] S1. Acquire data information of the target detection area; specifically includes the following steps:

[0052] Acquire data information of the target detection area; the data information includes the distribution range of the measurement line, the distribution range of the measurement points, the maximum depth to be measured and the data information of the object to be measured;

[0053] S2. According to the data information obtained in step S1, arrange the long-pole-distance power supply source and the short-pole-distance power supply source, and set the parameters of the power supply source; specifically comprising the following steps:

[0054] Arrange the long-pole-distance power supply source and the short-pole-distance power supply source according to the data information obtained in step S1;

[0055] Among them, the value of the short pole distance is 3 to 5 times the maximum detection depth; the value of the long pole distance is 2 times the short pole distance;

[0056] The current waveforms of the long-pole-distance power supply source and the short-pole-distance power supply source are both set to bipolar square waves;

[0057] During measurement, the power supply wire and the measuring wire must be separated and laid at a set distance. The set distance is at least

[0058] In specific implementation, the wiring of the long and short pole distance power supply source can refer to Figure 2 and Figure 3 The manner shown;

[0059] Figure 2 In the middle, the long and short pole spacing power supply lines are arranged in a "one" shape, where A1 and B1 are grounded, and A2 and B2 are grounded;

[0060] Figure 3 In the middle, the long pole distance power supply line is rectangular, S 2≥2L, short pole distance power supply line is "U" shaped, S 1 It is half of the line distance, A1 and B1 are grounded, and A2 and B2 are not grounded;

[0061] S3. Set the layout range of the measuring points; specifically include the following steps:

[0062] Set the measurement point layout range to: the middle of the short pole distance range, and short pole distance in the middle Both sides of the range within the scope;

[0063] S4. Setting the working model of the short-distance power supply source and the long-distance power supply source, and performing corresponding observations at the set measuring points; specifically comprising the following steps:

[0064] The short-distance power supply source is turned on, while the long-distance power supply source is turned off. The receiver is synchronized with the transmitter, and the axial electric field E is observed at each measuring point in turn. x Equatorial magnetic field H y ;

[0065] The short-distance power supply source is turned off, while the long-distance power supply source is turned on. The receiver is synchronized with the transmitter, and the axial electric field E is observed at each measuring point in turn. x Equatorial magnetic field H y ;

[0066] The axial direction is parallel to the line source direction, and the equatorial direction is perpendicular to the line source direction; Figure 4 As shown;

[0067] S5. Calculate electromagnetic sounding information based on the observation information obtained in step S4 to complete artificial source multi-polarization electromagnetic sounding; comprising the following steps:

[0068] Based on the observed electromagnetic field, the apparent resistivity, polarizability and magnetic permeability corresponding to different times are calculated;

[0069] According to the apparent depth corresponding to different times, the resistivity, polarizability and magnetic permeability at different depths are obtained through inversion calculation;

[0070] When step S5 is specifically implemented, it includes the following steps:

[0071] (1) Assume that the earth resistivity is ρ and the conductivity is σ The polarizability is m; the electric field in the x direction and the magnetic field in the y direction are observed at the measuring point P(x,y);

[0072] (2) When the short-distance power supply source is working and the long-distance power supply source is turned off, the power supply current amplitude is I, then

[0073] The x-component of the electric field during the power supply platform period Expressed as

[0074] Y-component of magnetic field during power supply platform period Expressed as Where A and B are the grounding points of the short power supply electrode, the center point of AB is the coordinate origin O, L is half of the power supply electrode distance AB, P is the observation point with coordinates (x, y); θ is ∠PAB and is ∠PBA and AP is the distance between the observation point and the power supply point A, and BP is the distance between the observation point and the power supply point B, and

[0075] The power supply platform period excites the underground polarized geological body, and then the power is cut off, and the polarized electric field that decays over time is measured. and polarization magnetic field Then get

[0076] Electro-induced television polarization ratio m se (t) is

[0077] Magnetic television polarization ratio m sh (t) is

[0078] Laser TV Depth for where D is the maximum detectable depth associated with the short supply electrode spacing 2L and N is a positive integer and N∈[4,10], t is the delay corresponding to the moment when the shutdown starts to be 0, T on is the duration of the supply current;

[0079] (3) When the short-distance power supply source is turned off and the long-distance power supply source is working, the transient induced electric field e that decays with time is observed at the moment of power disconnection. x (t) and the transient induced magnetic field h that decays with time y (t), then

[0080] when When T t is the set threshold, then the calculation is

[0081] Magnetic permeability μ s for

[0082] Resistivity ρ s for

[0083] TEM depth of view for Where t is the delay corresponding to the time when the shutdown starts at 0;

[0084] (4) Based on the data obtained in steps (2) and (3), the resistivity, permeability and polarizability at different depths are inverted.

[0085] like Figure 5 The functional module schematic diagram of the system of the present invention is shown as follows: the system for realizing the artificial source multi-polarization electromagnetic sounding method disclosed in the present invention comprises a data acquisition module, a field source arrangement module, a measuring point arrangement module, an observation module and an electromagnetic sounding module; the data acquisition module, the field source arrangement module, the measuring point arrangement module, the observation module and the electromagnetic sounding module are connected in series in sequence; the data acquisition module is used to acquire data information of the target detection area, and upload the data information to the field source arrangement module; the field source arrangement module is used to arrange long-pole-distance power supply field sources and short-pole-distance power supply field sources according to the received data information and the acquired data information, and set the parameters of the power supply field sources, and upload the data information to the measuring point arrangement module; the measuring point arrangement module is used to set the arrangement range of the measuring points according to the received data information, and upload the data information to the observation module; the observation module is used to set the working model of the short-pole-distance power supply field source and the long-pole-distance power supply field source according to the received data information, and perform corresponding observations at the set measuring points, and upload the data information to the electromagnetic sounding module; the electromagnetic sounding module is used to calculate the electromagnetic sounding information according to the received data information and the obtained observation information, and complete the artificial source multi-polarization electromagnetic sounding.

Claims

1. An artificial source multipolarization electromagnetic sounding method, comprising the following steps: S1. Obtain data information of the target detection area; S2. Arrange the long-pole-distance power supply source and the short-pole-distance power supply source according to the data information obtained in step S1, and set the parameters of the power supply source; S3. Set the layout range of the measuring points; S4. Setting the working model of the short-distance power supply source and the long-distance power supply source, and performing corresponding observations at the set measuring points; S5. Calculate electromagnetic sounding information based on the observation information obtained in step S4 to complete artificial source multi-polarization electromagnetic sounding.

2. The artificial source multipolarization electromagnetic sounding method according to claim 1, characterized in that The step S1 of acquiring data information of the target detection area specifically includes the following steps: Acquire data information of the target detection area; the data information includes the distribution range of the measurement lines, the distribution range of the measurement points, the maximum depth to be measured and the data information of the object to be measured.

3. The artificial source multipolarization electromagnetic sounding method according to claim 2, characterized in that The step S2 of arranging the long-pole-distance power supply source and the short-pole-distance power supply source according to the data information obtained in the step S1 and setting the parameters of the power supply source specifically includes the following steps: Arrange the long-pole-distance power supply source and the short-pole-distance power supply source according to the data information obtained in step S1; Among them, the value of the short pole distance is 3 to 5 times the maximum detection depth; the value of the long pole distance is 2 times the short pole distance; The current waveforms of the long-pole-distance power supply source and the short-pole-distance power supply source are both set to bipolar square waves; During measurement, the power supply wire and the measuring wire must be separated and laid at a set distance. The set distance is at least 4. The artificial source multipolarization electromagnetic sounding method according to claim 3, characterized in that The step S3 of setting the arrangement range of the measuring points specifically includes the following steps: Set the measurement point layout range to: the middle of the short pole distance range, and short pole distance in the middle Both sides of the range within the range.

5. The artificial source multipolarization electromagnetic sounding method according to claim 4, characterized in that The step S4 of setting the working model of the short-distance power supply source and the long-distance power supply source and performing corresponding observations at the set measuring points specifically includes the following steps: The short-distance power supply source is turned on, while the long-distance power supply source is turned off. The receiver is synchronized with the transmitter, and the axial electric field E is observed at each measuring point in turn. x Equatorial magnetic field H y ; The short-distance power supply source is turned off, while the long-distance power supply source is turned on. The receiver is synchronized with the transmitter, and the axial electric field E is observed at each measuring point in turn. x Equatorial magnetic field H y ; The axial direction is parallel to the line source direction, and the equatorial direction is perpendicular to the line source direction.

6. The artificial source multipolarization electromagnetic sounding method according to claim 5, characterized in that The step S5 of calculating electromagnetic sounding information based on the observation information obtained in step S4 to complete artificial source multi-polarization electromagnetic sounding includes the following steps: Based on the observed electromagnetic field, the apparent resistivity, polarizability and magnetic permeability corresponding to different times are calculated; According to the apparent depth corresponding to different times, the resistivity, polarizability and permeability at different depths are obtained by inversion calculation.

7. The artificial source multipolarization electromagnetic sounding method according to claim 6, characterized in that The step S5 specifically includes the following steps: (1) Assume that the earth resistivity is ρ and the conductivity is σ The polarizability is m; the electric field in the x direction and the magnetic field in the y direction are observed at the measuring point P(x,y); (2) When the short-distance power supply source is working and the long-distance power supply source is turned off, the power supply current amplitude is I, then The x-component of the electric field during the power supply platform period Expressed as Y-component of magnetic field during power supply platform period Expressed as Where A and B are the grounding points of the short power supply electrode, the center point of AB is the coordinate origin O, L is half of the power supply electrode distance AB, P is the observation point with coordinates (x, y); θ is ∠PAB and is ∠PBA and AP is the distance between the observation point and the power supply point A, and BP is the distance between the observation point and the power supply point B, and The power supply platform period excites the underground polarized geological body, and then the power is cut off, and the polarized electric field that decays over time is measured. and polarization magnetic field Then get Electro-induced television polarization ratio m se (t) is Magnetic television polarization ratio m sh (t) is Laser TV Depth for where D is the maximum detectable depth associated with the short supply electrode spacing 2L and N is a positive integer and N∈[4,10], t is the delay corresponding to the moment when the shutdown starts to be 0, T on is the duration of the supply current; (3) When the short-distance power supply source is turned off and the long-distance power supply source is working, the transient induced electric field e that decays with time is observed at the moment of power disconnection. x (t) and the transient induced magnetic field h that decays with time y (t), then when When T t is the set threshold, then the calculation is Magnetic permeability μ s for Resistivity ρ s for TEM depth of view for Where t is the delay corresponding to the time when the shutdown starts at 0; (4) Based on the data obtained in steps (2) and (3), the resistivity, permeability and polarizability at different depths are inverted.

8. A system for implementing the artificial source multi-polarization electromagnetic sounding method according to any one of claims 1 to 7, characterized in that It includes a data acquisition module, a field source arrangement module, a measuring point arrangement module, an observation module and an electromagnetic sounding module; the data acquisition module, the field source arrangement module, the measuring point arrangement module, the observation module and the electromagnetic sounding module are connected in series in sequence; the data acquisition module is used to acquire data information of the target detection area, and upload the data information to the field source arrangement module; the field source arrangement module is used to arrange long-pole-distance power supply field sources and short-pole-distance power supply field sources according to the received data information and the acquired data information, and set the parameters of the power supply field sources, and upload the data information to the measuring point arrangement module; the measuring point arrangement module is used to set the arrangement range of the measuring points according to the received data information, and upload the data information to the observation module; The observation module is used to set the working model of the short-distance power supply source and the long-distance power supply source according to the received data information, and to perform corresponding observations at the set measuring points, and upload the data information to the electromagnetic sounding module; The electromagnetic sounding module is used to calculate the electromagnetic sounding information based on the received data information and the obtained observation information, and complete the artificial source multi-polarization electromagnetic sounding.

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