A magnetotelluric device using array electric field acquisition

Abstract

The present invention discloses a magnetotelluric device using array electric field acquisition, comprising: N first electrodes connected in series on an electric field cable, and one electric field collector corresponding to each of the first electrodes; one first magnetic field sensor connected to each electric field collector is provided every M electric field collectors, and one magnetic field collector corresponds to each of the first magnetic field sensors, wherein M is an odd number, M < N / 2, and (M - 1) / 2 electric field collectors in front of and behind each first magnetic field sensor share the first magnetic field sensor. The magnetotelluric device using array electric field acquisition not only saves electrodes and sensors in layout, but also can achieve the same detection effect principle.

Description

Technical Field

[0001] The present invention relates to the field of geological exploration technology, and in particular to a magnetotelluric device using array electric field acquisition. Background Art

[0002] Audio magnetotellurics (AMT) is a frequency domain electromagnetic exploration method based on Maxwell's electromagnetic induction principle and utilizing the differences in rock conductivity. It mainly uses the resistivity differences between different geological bodies to make judgments and infer the spatial morphology of deep geological bodies based on the resistivity variation pattern within a certain range.

[0003] Currently, there are two common methods for AMT field data collection. One is single-station data collection, where a single collection station uses independent electric and magnetic field sensors to simultaneously measure four electromagnetic field components: two electric field components (Ex, Ey) and two magnetic field components (Hx, Hy). For example, the EH4 instrument produced by Geometrics in the United States uses a single-station measurement method. This data collection method can only measure one point at a time. When using vector acquisition, four independent electrode wires and electrode sensors, and two magnetic bar wires and magnetic field sensors are used. Four electrodes must be arranged in a cross pattern, and obstacles in all four directions must be cleared. For an area measurement task, the measurement can only be performed by moving along a single point along the survey line. This results in high workload, low efficiency, and long data collection time.

[0004] The second method uses a single host computer paired with two or more data acquisition boxes. This data acquisition method is currently supported by the V8 system produced by Phoenix, a Canadian company. This method, based on the premise that magnetic field variations are minimal within a certain range, shares magnetic field data collected by the host computer, while the other data acquisition boxes only collect electric field data. This method utilizes GPS time synchronization and can simultaneously collect data from multiple measurement points. However, it still requires the deployment of cross-shaped electrodes at each measurement point and the removal of obstacles in four directions. This is labor-intensive and offers limited efficiency gains. For detailed area surveys, this method still requires a long time to collect field data.

[0005] Therefore, it is necessary to provide a magnetotelluric device that can be constructed efficiently and uses array electric field acquisition. Summary of the Invention

[0006] The main purpose of the present invention is to provide a new magnetotelluric device using array electric field acquisition to solve the above technical problems.

[0007] To achieve the above-mentioned object, the present invention provides a magnetotelluric device using array electric field acquisition, comprising:

[0008] N first electrodes connected in series on an electric field cable, and one electric field collector is correspondingly arranged for each of the first electrodes;

[0009] One first magnetic field sensor connected to the electric field collector is arranged every M electric field collectors, and one magnetic field collector is correspondingly arranged for each of the first magnetic field sensors. Wherein, M is an odd number, M < N / 2, and (M - 1) / 2 electric field collectors in front of and behind each first magnetic field sensor share the first magnetic field sensor.

[0010] Preferably, when the magnetotelluric device using array electric field collection is a unidirectional magnetotelluric device, the first electrode is a near electrode, and the near electrode is arranged along the point position direction of the measuring line; the first magnetic field sensor is arranged perpendicular to the direction of the measuring line.

[0011] Preferably, when the magnetotelluric device using array electric field collection is a vector bidirectional magnetotelluric device, the electric field collector is further connected with a second electrode, the distance between the second electrode and the electric field collector is greater than the distance between the first electrode and the electric field collector, and the arrangement direction of the second electrode is perpendicular to that of the first electrode; the magnetic field collector is further connected with a second magnetic field sensor, and the arrangement direction of the second magnetic field sensor is perpendicular to that of the first magnetic field sensor.

[0012] Preferably, the first electrode is a near electrode, and the near electrode is arranged along the point position direction of the measuring line; the second electrode is a far electrode, and the far electrode is arranged perpendicular to the direction of the measuring line; the first magnetic field sensor is arranged perpendicular to the direction of the measuring line, and the second magnetic field sensor is arranged parallel to the direction of the measuring line.

[0013] Preferably, the magnetic field collector includes one or two magnetic field collection circuits corresponding to the first magnetic field sensor and / or the second magnetic field sensor. The magnetic field collection circuit includes a magnetic field signal conditioning circuit, a magnetic field signal acquisition circuit, a magnetic field collection controller and a synchronous trigger circuit. The magnetic field signal conditioning circuit is connected to the first magnetic field sensor and / or the second magnetic field sensor. The magnetic field signal acquisition circuit receives the signal transmitted by the magnetic field signal conditioning circuit, acquires it and then sends it to the magnetic field collection controller. The synchronous trigger circuit is connected to the electric field signal acquisition circuit;

[0014] The electric field collector includes one or two circuit acquisition circuits corresponding to the first electrode and / or the second electrode. The circuit acquisition circuit includes an electric field signal conditioning circuit, a magnetic and electric field signal acquisition circuit, an electric acquisition controller, and a synchronous trigger circuit. The electric field signal conditioning circuit is connected to the first electrode and / or the second electrode. The electric field signal acquisition circuit receives the signal transmitted by the electric field signal conditioning circuit, acquires it, and then sends it to the electric acquisition controller. The synchronous trigger circuit is connected to the magnetic field signal acquisition circuit;

[0015] The electric acquisition controller and the magnetic acquisition controller are connected to a network communication circuit and send the acquired electric field signals and magnetic field signals out through the network communication circuit.

[0016] Preferably, the network communication circuit is connected to a network switch.

[0017] For the magnetotelluric device with array electric field acquisition provided by the present invention, N first electrodes are connected in series on one electric field cable, and one electric field collector is correspondingly arranged for each of the first electrodes; one first magnetic sensor connected to the electric field collector is arranged every M electric field collectors, and one magnetic field collector is correspondingly arranged for each of the first magnetic sensors, where M is an odd number and M < N / 2, and the (M - 1) / 2 electric field collectors in front of and behind each of the first magnetic sensors share the first magnetic sensor.

[0018] Compared with traditional devices, when collecting single-component measurement points, two electrodes and one magnetic sensor need to be arranged for each measurement point. For example, for scalar unidirectional magnetotelluric measurement, a survey line of 1 km needs to be arranged, 41 sets of equipment need to be arranged, 2 electrodes and 1 magnetic sensor are required each time, a total of 82 electrode arrangements and 41 magnetic sensor arrangements are needed. For the magnetotelluric device with array electric field acquisition of the present application, the survey line arrangement distance is 1 km, and a total of 41 near electrodes, 4 first magnetic sensors and magnetic field collectors are arranged.

[0019] For traditional magnetotelluric devices, when using vector bidirectional magnetotelluric measurement, the following arrangements need to be completed for each vector measurement point. Each arrangement requires 4 electrodes and 2 magnetic sensors, and a total of 41 sets of equipment need to be arranged. 4 electrodes (2 parallel directions, 2 vertical directions) and 2 magnetic sensors are required each time, a total of 164 electrode arrangements and 82 magnetic sensor arrangements are needed; for the magnetotelluric device with array electric field acquisition of the present application, the survey line arrangement distance is 1 km. On the basis of the unidirectional measurement device, a second electrode is connected to each electric field collector, and a second magnetic sensor is connected to each magnetic field collector. In this way, for the construction arrangement, a survey line of 1 km, 41 near electrodes, 41 vertical far electrodes, and 8 magnetic sensors need to be arranged.

[0020] The principle that the array device not only saves electrodes and sensors in layout but can also achieve the same detection effect. Brief Description of the Drawings

[0021] Figure 1 Schematic diagram of the module structure of a magnetotelluric device using array electric field acquisition in a one-way magnetotelluric measurement scenario in an embodiment of the present invention;

[0022] Figure 2 Schematic diagram of the module structure of a magnetotelluric device using array electric field acquisition in a vector two-way magnetotelluric measurement scenario in an embodiment of the present invention;

[0023] Figure 3 Schematic diagram of the module structure of a magnetic field collector in an embodiment of the present invention;

[0024] Figure 4 Schematic diagram of the module structure of an electric field collector in an embodiment of the present invention;

[0025] Figure 5 Schematic diagram of the network connection structure in an embodiment of the present invention.

[0026] The implementation, functional features and advantages of the present invention will be further described with reference to the embodiments and the accompanying drawings. Detailed Embodiments

[0027] 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.

[0028] In the following description, suffixes such as "module", "component" or "unit" used to represent elements are only for the convenience of describing the present invention and have no specific meaning in themselves. Therefore, "module", "component" or "unit" can be used interchangeably.

[0029] Please refer to Figure 1-4 , to achieve the above object, a magnetotelluric device using array electric field acquisition provided in an embodiment of the present invention includes:

[0030] N first electrodes connected in series on an electric field cable, and an electric field collector is correspondingly arranged for each of the first electrodes;

[0031] A first magnetic field sensor connected to the electric field collector is arranged every M electric field collectors, and a magnetic field collector is correspondingly arranged for each of the first magnetic field sensors, where M is an odd number, M < N / 2, and the (M - 1) / 2 electric field collectors in front of and behind each first magnetic field sensor share the first magnetic field sensor.

[0032] Specifically, a series electric field signal cable is used for electric field signal acquisition. One electric field cable is used to connect N first electrodes in series, and an electric field collector is arranged for each first electrode.

[0033] Every M (usually M < N / 2) electric field collectors are provided with a magnetic field sensor and a collector. The (M - 1) / 2 electric field collectors before and after the magnetic field sensor share this one magnetic field sensor.

[0034] Preferably, when the magnetotelluric device using array electric field acquisition is a unidirectional magnetotelluric device, the first electrode is a near electrode, and the near electrode is arranged along the point position direction of the survey line; the first magnetic field sensor is arranged perpendicular to the direction of the survey line.

[0035] At this time, the electrodes used, since they are directly clamped on the electric field sensor and the electrode arrangement is very close (usually closely arranged), are called near electrodes. The near electrodes are generally arranged along the point position of the survey line. The first magnetic field sensor is arranged perpendicular to the direction of the survey line.

[0036] In contrast, when traditional equipment acquires single-component measurement points, two electrodes and one magnetic field sensor need to be arranged for each measurement point. For example, for scalar unidirectional magnetotelluric measurement, a survey line of 1 km needs to be arranged, 41 sets of equipment need to be arranged, 2 electrodes and 1 magnetic field sensor are required each time, with a total of 82 electrode arrangements and 41 magnetic field sensor arrangements; the magnetotelluric device using array electric field acquisition only needs to arrange 41 near electrodes and 4 magnetic field sensors.

[0037] Preferably, when the magnetotelluric device using array electric field acquisition is a vector bidirectional magnetotelluric device, the electric field collector is further connected with a second electrode, and the distance between the second electrode and the electric field collector is greater than the distance between the first electrode and the electric field collector, and the arrangement direction of the second electrode is perpendicular to that of the first electrode; the magnetic field collector is further connected with a second magnetic field sensor, and the arrangement direction of the second magnetic field sensor is perpendicular to that of the first magnetic field sensor.

[0038] Preferably, the first electrode is a near electrode, and the near electrode is arranged along the point position direction of the survey line; the second electrode is a far electrode, and the far electrode is arranged perpendicular to the direction of the survey line; the first magnetic field sensor is arranged perpendicular to the direction of the survey line, and the second magnetic field sensor is arranged parallel to the direction of the survey line. The second electrode is arranged perpendicular to the survey line during construction, and the distance from the electric field collector is one electrode spacing (such as 25 m), which is called a vertical far electrode. The second magnetic field sensor is arranged parallel to the direction of the survey line.

[0039] Specifically, when using vector bidirectional magnetotelluric measurements, for traditional magnetotelluric equipment, the following layout must be completed for each vector measuring point: each layout requires the layout of 4 electrodes and 2 magnetic field sensors; the magnetotelluric device using array electric field acquisition only needs to arrange the equipment 41 times, each time requiring 4 electrodes (2 parallel directions, 2 vertical directions) and 2 magnetic field sensors, a total of 164 electrode arrangements and 82 magnetic field sensor arrangements; the magnetotelluric device using array electric field acquisition, based on the unidirectional measurement device, each electric field collector is connected to the second electrode, and each magnetic field collector is connected to the second magnetic field sensor. In this way, the construction layout only requires the layout of a 1-kilometer survey line, 41 near electrodes, 41 vertical far electrodes, and 8 magnetic field sensors.

[0040] The magnetotelluric device that uses array electric field acquisition not only saves on electrodes and sensors, but also can achieve the same detection effect.

[0041] Preferably, the magnetic field collector includes one or two magnetic field acquisition circuits corresponding to the first magnetic field sensor and / or the second magnetic field sensor, the magnetic field acquisition circuit includes a magnetic field signal conditioning circuit, a magnetic field signal acquisition circuit, a magnetic acquisition controller and a synchronous trigger circuit, the magnetic field signal conditioning circuit is connected to the first magnetic field sensor and / or the second magnetic field sensor, the magnetic field signal acquisition circuit receives the signal transmitted by the magnetic field signal conditioning circuit and sends it to the magnetic acquisition controller after acquisition, and the synchronous trigger circuit is connected to the electric field signal acquisition circuit;

[0042] The electric field collector includes one or two electric field acquisition circuits corresponding to the first electrode and / or the second electrode, and the electric field acquisition circuit includes an electric field signal conditioning circuit, a magnetic field signal acquisition circuit, an electric field acquisition controller, and a synchronous trigger circuit. The electric field signal conditioning circuit is connected to the first electrode and / or the second electrode. The electric field signal acquisition circuit receives the signal transmitted by the electric field signal conditioning circuit and collects and sends it to the electric field acquisition controller. The synchronous trigger circuit is connected to the magnetic field signal acquisition circuit.

[0043] The electric field acquisition controller and the magnetic field acquisition controller are connected to a network communication circuit and send out corresponding collected electric field signals and magnetic field signals through the network communication circuit.

[0044] Preferably, the network communication circuit is connected to a network switch. Figure 5Each network switch acts as a node, connecting to other nodes using an Ethernet network (wired or wireless). Nodes with a sequence number one less than the current node are called the left node, and nodes with a sequence number one greater than the current node are called the right node. For example, each node provides Wi-Fi, allowing users to set instrument parameters and view instrument data using a handheld terminal while roaming between nodes. The dense Wi-Fi network nodes are designed to accommodate field work environments where Wi-Fi signals are easily obstructed by terrain and trees and vegetation, ensuring that users can receive a valid Wi-Fi signal as long as they are near any node. The Wi-Fi network operates in AP mode, with user handheld terminals acting as stations to access the Wi-Fi network. The Wi-Fi network's SSID is set to a single name, and the wireless channel number is the modulo 16 of the node number.

[0045] The above are only preferred embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention description and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A magnetotelluric device using array electric field acquisition, characterized in that: Including: N first electrodes connected in series on an electric field cable, with an electric field collector corresponding to each of the first electrodes; A first magnetic field sensor connected to every Mth electric field collector is provided, and a magnetic field collector corresponds to each first magnetic field sensor. Here, M is an odd number, M < N / 2, and the (M - 1) / 2 electric field collectors before and after each first magnetic field sensor share this first magnetic field sensor.

2. The magnetotelluric device using array electric field acquisition according to claim 1, characterized in that: When the magnetotelluric device using array electric field collection is a unidirectional magnetotelluric device, the first electrode is a near electrode, and the near electrode is arranged along the point position direction of the survey line; the first magnetic field sensor is arranged perpendicular to the direction of the survey line.

3. The magnetotelluric device using array electric field acquisition according to claim 1, characterized in that: When the magnetotelluric device using array electric field collection is a vector bidirectional magnetotelluric device, the electric field collector is further connected to a second electrode, and the distance between the second electrode and the electric field collector is greater than the distance between the first electrode and the electric field collector, and the arrangement direction of the second electrode is perpendicular to that of the first electrode; the magnetic field collector is further connected to a second magnetic field sensor, and the arrangement direction of the second magnetic field sensor is perpendicular to that of the first magnetic field sensor.

4. The magnetotelluric device using array electric field acquisition according to claim 3, characterized in that: The first electrode is a near electrode, and the near electrode is arranged along the point position direction of the survey line; the second electrode is a far electrode, and the far electrode is arranged perpendicular to the direction of the survey line; the first magnetic field sensor is arranged perpendicular to the direction of the survey line, and the second magnetic field sensor is arranged parallel to the direction of the survey line.

5. The magnetotelluric device using array electric field acquisition according to claim 3, characterized in that: The magnetic field collector includes one or two magnetic field collection circuits corresponding to the first magnetic field sensor and / or the second magnetic field sensor. The magnetic field collection circuit includes a magnetic field signal conditioning circuit, a magnetic field signal acquisition circuit, a magnetic field acquisition controller, and a synchronous trigger circuit. The magnetic field signal conditioning circuit is connected to the first magnetic field sensor and / or the second magnetic field sensor. The magnetic field signal acquisition circuit receives the signal transmitted by the magnetic field signal conditioning circuit, acquires it, and then sends it to the magnetic field acquisition controller. The synchronous trigger circuit is connected to the electric field signal acquisition circuit; the electric field collector includes one or two circuit collection circuits corresponding to the first electrode and / or the second electrode. The circuit collection circuit includes an electric field signal conditioning circuit, an electric field signal acquisition circuit, an electric field acquisition controller, and a synchronous trigger circuit. The electric field signal conditioning circuit is connected to the first electrode and / or the second electrode. The electric field signal acquisition circuit receives the signal transmitted by the electric field signal conditioning circuit, acquires it, and then sends it to the electric field acquisition controller. The synchronous trigger circuit is connected to the magnetic field signal acquisition circuit; the electric field acquisition controller and the magnetic field acquisition controller are connected to a network communication circuit and send the corresponding acquired electric field signals and magnetic field signals through the network communication circuit.

6. The magnetotelluric device using array electric field acquisition according to claim 5, characterized in that: The network communication circuit is connected to a network switch.

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