A semi-submarine electromagnetic detection device and method

Abstract

The application discloses a kind of semi-submarine electromagnetic detection device and method, solve the technical problem that present technical cannot accurately characterize deep sulfide mine distribution.Its device includes seabed fixed transmitting device, underwater autonomous robot receiving system, the seabed fixed transmitting system includes seabed current source transmitting device and anchoring unit, sensor receiving array and data acquisition module are installed on the underwater autonomous robot receiving system;The seabed current source transmitting device includes transmitting source control bin, first watertight cable, transmitting end positive pole and transmitting end negative pole, the anchoring unit includes anchor body, acoustic positioning beacon, the sensor receiving array includes electric field collection bin, second watertight cable and several pairs of Ag / AgCl non-polarization electrode and three-component magnetometer.The application can more accurately detect the distribution characteristics of deep seabed sulfide, reduce drilling risk, improve the accuracy of exploration and the reliability of resource quantity evaluation.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of marine geophysics, and particularly relates to a semi-submarine electromagnetic detection device and method. BACKGROUND

[0002] Seafloor polymetallic sulfide is rich in copper, zinc, silver and gold, and is an important potential strategic metal source. The existing detection methods, such as seafloor transient electromagnetic method, have the transmitting loop located in the high-conductivity seawater, and the electromagnetic energy penetrating the seafloor is limited, so the detection depth is shallow, and it is difficult to accurately detect the sulfide deposit with a depth of more than 80 m. Therefore, it is urgent to develop an electromagnetic method with both detection depth and detection efficiency to improve the detection capability of the middle-deep sulfide in the seafloor. At the same time, the traditional inversion has a high requirement for the collection quality of the detection data, and it is necessary to propose a sulfide indicator based on data driving to realize the rapid identification and delineation of the sulfide distribution. Therefore, the application provides a semi-submarine electromagnetic device with a fixed transmitting source on the seafloor and underwater mobile collection, and provides the detection capability of the high-deep seafloor sulfide. SUMMARY

[0003] The application aims to provide a semi-submarine electromagnetic detection device and method to solve the technical problem that the existing technology cannot accurately characterize the middle-deep sulfide ore form in the seafloor.

[0004] To achieve the above-mentioned purpose, the application provides the following technical solutions.

[0005] In a first aspect, the application provides a semi-submarine electromagnetic detection device, which comprises a seafloor fixed transmitting device and an underwater autonomous robot receiving system, the seafloor fixed transmitting device comprises a seafloor current source transmitting device and an anchoring unit, and the underwater autonomous robot receiving system is provided with a sensor receiving array and a data acquisition module.

[0006] Further, the seafloor current source transmitting device comprises a transmitting source control bin, a first water-tight cable, a transmitting end positive electrode and a transmitting end negative electrode, the transmitting source control bin is connected with the transmitting end positive electrode and the transmitting end negative electrode through the first water-tight cable, and the current source transmitting device transmits a primary current field to the seafloor through the transmitting end.

[0007] Further, the sensor receiving array comprises an electric field collection bin, a second water-tight cable and a plurality of pairs of Ag / AgCl non-polarizable electrodes and a three-component magnetometer, the electric field collection bin and the three-component magnetometer are fixed on the shell of the underwater autonomous robot receiving system, the second water-tight cable is installed at the end of the underwater autonomous robot, the Ag / AgCl non-polarizable electrodes are distributed and arranged on the tail of the underwater autonomous robot receiving system and the second water-tight cable, and the sensor receiving array is used for receiving the secondary electromagnetic field data generated by the seafloor sulfide induction.

[0008] Further, the anchoring unit of the seabed fixed transmission system comprises an anchor body, a buoyancy adjusting assembly and an acoustic positioning beacon, the anchoring unit keeps the transmission coil posture stable in the environment with a sea current speed ≤ 3 m / s through load adjustment, the posture deviation is ≤ 5°, and the acoustic positioning beacon is sequentially arranged at the head end and tail end of the first water-tight cable and used for positioning the end point positions of the seabed fixed transmission source.

[0009] Further, the transmission source can generate an alternating electromagnetic field with a frequency range of 64 Hz-2048 Hz and support frequency multiplication step adjustment with a multiplication factor of 2; the distance between the positive pole of the transmission end and the negative pole of the transmission end is 200 meters, and the transmission waveform is a bipolar square wave.

[0010] Further, the receiving sensor array of the underwater mobile receiving system is a multi-component electric field sensor and a magnetic field sensor, the spatial arrangement distance between two adjacent Ag / AgCl non-polarized electrodes is 2-4 meters, so as to cover the main lobe area of the electromagnetic field radiated by the transmission system, and the receiving frequency of the receiving end Ag / AgCl non-polarized electrode and the multi-component magnetometer is set to 64 Hz-2048 Hz.

[0011] Further, the underwater autonomous robot receiving system carries out the collection of electric field and magnetic field signals according to the planned path, and in the collection process, the underwater autonomous robot receiving system is controlled to be 15 meters away from the seabed and the speed is controlled to be 1 m / s.

[0012] In the second aspect, the application provides a seabed polymetallic sulfide detection method based on the above device, comprising the following steps:

[0013] Deploying the transmission system: transporting the seabed fixed transmission system to the target area by the research ship, fixing the seabed fixed transmission system to the seabed by the anchoring unit, debugging the parameters of the transmission source and starting the electromagnetic field transmission;

[0014] Planning the receiving path: planning the cruise path and the survey line distribution of the underwater autonomous robot receiving system according to the position, direction and detection range of the seabed transmission system, planning the survey line to be parallel to the long axis direction of the transmission source, and ensuring that the underwater autonomous robot receiving system moves along the preset trajectory in the electromagnetic field coverage area, and the underwater mobile receiving system collects the secondary electromagnetic signals in real time during the movement, positions the data and records the synchronization time stamp of the transmission signal;

[0015] Data processing and analysis: based on the amplitude, phase characteristics and positioning information of the received signal, calculating the sulfide indicator factor of the electric field and the magnetic field, and identifying the spatial position and scale of the seabed polymetallic sulfide.

[0016] Further, the calculation formula of the sulfide indicator factor is as follows:

[0017]

[0018]

[0019] wherein, is the electric field sulfide indicator factor, represents the electric field component in the direction of the long axis of the fixed transmitter parallel to the seabed, the electric field component in the direction of the fixed transmitter parallel to the seabed above the sulfide, is the electric field component in the direction of the fixed transmitter parallel to the seabed, is the magnetic field sulfide indicator factor, represents the magnetic field component in the direction of the long axis of the fixed transmitter perpendicular to the seabed, the horizontal magnetic field component in the direction of the fixed transmitter perpendicular to the seabed above the sulfide, is the electric field component in the direction of the fixed transmitter perpendicular to the seabed.

[0020] Based on the above technical solution, the embodiments of the present application can at least produce the following technical effects:

[0021] (1) The semi-seabed electromagnetic detection device provided by the present application has a fixed transmitter on the seabed and directly contacts the seabed, can send a large power alternating current to the seabed, and can make the sulfide in the deep part of the seabed produce an induced secondary field, thereby improving the detection depth of the electromagnetic method. Through the underwater autonomous robot receiving system, the array sensor is moved to collect the induced electromagnetic secondary field parameters, combined with the multi-frequency transmission of the transmitter, the three-dimensional detection of the space and depth direction of the sulfide ore body at different depths is realized, and the exploration efficiency is improved.

[0022] (2) The semi-seabed electromagnetic detection method provided by the present application can more accurately explain the distribution characteristics of the seabed sulfide by obtaining the measured data of different regional backgrounds, through normalization analysis, and comprehensively analyzing the electric field and magnetic field data, thereby reducing the multi-solution and improving the accuracy and reliability of the exploration. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of the drawings shown.

[0024] Fig. 1 is a semi-seabed electromagnetic detection schematic diagram of the present application;

[0025] Fig. 2 is a typical semi-seabed electromagnetic detection electric field sulfide indicator factor distribution diagram;

[0026] Fig. 3 Typical semi-submarine electromagnetic exploration magnetic field sulfide indicator factor Distribution map

[0027] In the figure: 1, submarine fixed transmitter; 101, transmitter source control bin; 102, first water-tight cable; 103, positive emitter end; 104, negative emitter end; 105, anchor body; 106, acoustic positioning beacon; 2, underwater autonomous robot receiving system; 201, electric field collection bin; 202, second water-tight cable; 203, Ag / AgCl non-polarization electrode; 204, three-component magnetometer; 3, primary current field; 4, planned path DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present application will be described clearly and completely below. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the protection scope of the present application. In addition, the technical solutions of various embodiments can be combined with each other, but it must be based on that the combination of technical solutions can be realized by those skilled in the art. When the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, and is not within the protection scope of the present application.

[0029] The present embodiment provides a semi-submarine electromagnetic exploration device and method, which will be described below in combination with the accompanying drawings Figs. 1-3 .

[0030] Embodiment 1

[0031] Please refer to Fig. 1 , a semi-submarine electromagnetic exploration device, comprising a submarine fixed transmitter 1 and an underwater autonomous robot receiving system 2, the submarine fixed transmitter 1 comprises a submarine current source transmitter and an anchoring unit, the underwater autonomous robot receiving system 2 is provided with a sensor receiving array and a data acquisition module;

[0032] In the present embodiment, the submarine current source transmitter comprises a transmitter source control bin 101, a first water-tight cable 102, a positive emitter end 103 and a negative emitter end 104, the transmitter source control bin 101 is connected with the positive emitter end 103 and the negative emitter end 104 through the first water-tight cable 102, and the current source transmitter 1 emits a primary current field 3 to the seabed through the emitter end;

[0033] The sensor receiving array comprises an electric field collection bin 201, a second water-tight cable 202, a plurality of pairs of Ag / AgCl non-polarizable electrodes 203, and a three-component magnetometer 204, the electric field collection bin 201 and the three-component magnetometer 204 are fixed on the shell of the underwater autonomous robot receiving system 2, the second water-tight cable 202 is installed at the end of the underwater autonomous robot 2, the Ag / AgCl non-polarizable electrodes 203 are distributed on the tail of the underwater autonomous robot receiving system 2 and the second water-tight cable 202, and the sensor receiving array is used for receiving the secondary electromagnetic field data generated by the seabed sulfide induction, in the embodiment, the measured electric field component is the survey line component consistent with the direction of the robot.

[0034] In the embodiment, the anchoring unit of the seabed fixed transmitting system comprises an anchor body 105 and an acoustic positioning beacon 106, the anchoring unit keeps the transmitting coil posture stable through load adjustment, and the acoustic positioning beacon 106 is sequentially distributed at the head end and the tail end of the first water-tight cable 102, and is used for positioning the end point position of the seabed fixed transmitting source.

[0035] In the embodiment, the transmitting source 101 can generate alternating electromagnetic fields with frequencies of 256 Hz, 512 Hz, 1024 Hz and 2048 Hz, the spacing between the transmitting end positive pole 103 and the transmitting end negative pole 104 is 200 meters, the transmitting waveform is a bipolar square wave, and the transmitting current is 100 A.

[0036] In the embodiment, the receiving sensor array of the underwater mobile receiving system is a multi-component electric field sensor and a magnetic field sensor, the spatial arrangement spacing between two adjacent Ag / AgCl non-polarizable electrodes 203 is 2 meters, the electric field along the survey line direction and the electric field in the vertical direction are measured respectively, so as to cover the main lobe region of the electromagnetic field radiated by the transmitting system, and the receiving frequency of the receiving end Ag / AgCl non-polarizable electrode and the multi-component magnetometer is set to 256 Hz-2048 Hz.

[0037] In the embodiment, the underwater autonomous robot receiving system 2 collects electric field and magnetic field signals according to the planned path 4, the main survey line direction of the planned path 4 is parallel to the long axis direction of the transmitting source, in the collection process, the underwater autonomous robot receiving system 2 is controlled to be 15 meters away from the seabed, and the speed is controlled to be 1 m / s.

[0038] Embodiment 2

[0039] Please refer to Figs. 2-3 The embodiment provides a semi-seabed electromagnetic detection method, comprising the following steps:

[0040] Deploying the transmitting system: transporting the seabed fixed transmitting system to the target area by the research ship, fixing the transmitting system to the seabed by the anchoring unit, debugging the transmitting source parameters and starting the electromagnetic field transmission.

[0041] Planning receiving path: according to the position, direction and detection range of the submarine transmitting system, the cruise path and the line distribution of the underwater autonomous robot receiving system are planned, as shown in Fig. 2 and Fig. 3 As shown, the sulfide is located in the center of the detection area, the sulfide distribution is 50m*50m, so the line length is planned to be 400m, parallel to the long axis direction (Y direction) of the transmitting source, and the mobile underwater receiving system collects the secondary electromagnetic signals in real time during the movement;

[0042] Data processing and analysis: based on the amplitude, phase characteristics and positioning information of the received signals, the sulfide indicator factors of the electric field and the magnetic field are calculated, and the spatial position and scale of the submarine polymetallic sulfide are identified.

[0043] Specifically, the calculation formula of the sulfide indicator factor is as follows:

[0044]

[0045]

[0046] Among them, is the electric field sulfide indicator factor, represents the electric field component parallel to the long axis direction of the fixed transmitting source on the seabed, the electric field component parallel to the direction of the transmitting source above the sulfide, is the electric field component parallel to the direction of the transmitting source; is the magnetic field sulfide indicator factor, represents the magnetic field component perpendicular to the long axis direction of the fixed transmitting source on the seabed, the horizontal component of the magnetic field perpendicular to the direction of the transmitting source above the sulfide, is the electric field component perpendicular to the direction of the transmitting source. The calculated As shown in Fig. 2 As shown in As shown in Fig. 3 The electric field and magnetic field sulfide indicator factors can indicate the distribution of sulfide.

[0047] The present application provides a kind of semi-submarine electromagnetic detection device and method, by not being set fixed transmitting source on seabed realizes the identification and detection of seabed sulfide, detection device can obtain the fine structure of seabed sulfide, serve the accurate exploration and resource evaluation of southwest Indian Ocean sulfide contract area of our country.

[0048] The above shows and describes the basic principles and main features of the present application and the advantages of the present application. Those skilled in the art should understand that the present application is not limited to the above embodiments, and the above embodiments and descriptions in the specification are only to illustrate the principles of the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the claimed present application. The scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A semi-seabed electromagnetic detection device, characterized in that, It includes a fixed seabed launcher (1) and an underwater autonomous robot receiving system (2). The fixed seabed launcher (1) includes a seabed current source launcher and an anchoring unit. The underwater autonomous robot receiving system (2) is equipped with a sensor receiving array and a data acquisition module. The submarine current source transmitting device includes a transmitting source control chamber (101), a first watertight cable (102), a transmitting positive pole (103), and a transmitting negative pole (104). The transmitting source control chamber (101) is connected to the transmitting positive pole (103) and the transmitting negative pole (104) through the first watertight cable (102). The submarine fixed transmitting device (1) transmits a primary current field (3) to the seabed through the transmitting terminal. The sensor receiving array includes an electric field acquisition chamber (201), a second watertight cable (202), several pairs of Ag / AgCl non-polarizing electrodes (203), and a three-component magnetometer (204). The electric field acquisition chamber (201) and the three-component magnetometer (204) are fixed on the outer shell of the underwater autonomous robot receiving system (2). The second watertight cable (202) is installed at the end of the underwater autonomous robot receiving system (2). The Ag / AgCl non-polarizing electrodes (203) are distributed at the tail of the underwater autonomous robot receiving system (2) and on the second watertight cable (202). The sensor receiving array is used to receive secondary electromagnetic field data generated by seabed sulfide induction. The sensor receiving array of the underwater autonomous robot receiving system (2) is a multi-component electric field sensor and a magnetic field sensor. The anchoring unit of the fixed seabed launch system (1) includes an anchor body (105) and an acoustic positioning beacon (106). The anchoring unit adjusts the load to keep the launch coil attitude stable in an environment with a current speed ≤3m / s and an attitude deviation ≤5°. The acoustic positioning beacon (106) is distributed sequentially at the head and tail ends of the first watertight cable (102) and is used to locate the endpoint position of the fixed seabed launch source.

2. The semi-seabed electromagnetic detection device according to claim 1, characterized in that, The transmitter control chamber (101) can generate an alternating electromagnetic field with a frequency range of 64Hz-2048Hz and supports frequency doubling step adjustment with an adjustment factor of 2.

3. The semi-seabed electromagnetic detection device according to claim 1, characterized in that, The distance between the positive pole (103) and the negative pole (104) at the transmitting end is 200 meters, and the transmitted waveform is a bipolar square wave.

4. The semi-seabed electromagnetic detection device according to claim 1, characterized in that, The spatial spacing between two adjacent Ag / AgCl non-polarized electrodes (203) is 2-4 meters to cover the main lobe region of the electromagnetic field radiated by the transmitting system. The receiving frequency of the receiving end Ag / AgCl non-polarized electrode (203) and the three-component magnetometer (204) is set to 64Hz-2048Hz.

5. The semi-seabed electromagnetic detection device according to claim 1, characterized in that, The underwater autonomous robot receiving system (2) collects electric and magnetic field signals according to the planned path (4). During the collection process, the underwater autonomous robot receiving system (2) is controlled at a height of 15 meters above the seabed and at a speed of 1 m / s.

6. A semi-seabed electromagnetic detection method, using the device described in any one of claims 1-5 for detection, characterized in that, Includes the following steps: Deployment of the launch system: The seabed fixed launch system is transported to the target area by a research vessel, fixed to the seabed using anchoring units, and the launch source parameters are adjusted and electromagnetic field launch is initiated. Planning the receiving path: Based on the location, orientation, and detection range of the seabed transmitting system, plan the cruising path and survey line distribution of the underwater autonomous robot receiving system. The planned survey lines should be parallel to the long axis of the transmitting source and ensure that the underwater autonomous robot receiving system moves along a preset trajectory within the electromagnetic field coverage area. The underwater mobile receiving system collects secondary electromagnetic signals in real time during the movement, locates the data, and records the synchronization timestamp with the transmitted signal. Data processing and analysis: Based on the amplitude and phase characteristics of the received signal and the positioning information, calculate the sulfide indicator factors of the electric and magnetic fields to identify the spatial location and scale of polymetallic sulfides on the seabed.

7. The semi-seabed electromagnetic detection method according to claim 6, characterized in that, The formula for calculating the sulfide indicator factor is as follows: ; ; in, As an indicator factor for electric field sulfides, This represents the electric field component along the long axis of the fixed emission source parallel to the seabed. The electric field component above the sulfide, parallel to the direction of the emission source. The electric field component is parallel to the direction of the emission source; As a magnetic field sulfide indicator, This represents the magnetic field component perpendicular to the long axis of the fixed seabed source. The horizontal component of the magnetic field above the sulfide, perpendicular to the direction of the emission source. This represents the magnetic field component perpendicular to the direction of the emission source.

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