High-resolution natural source electromagnetic field acquisition equipment in the field

Abstract

The present disclosure relates to a high-resolution natural source electromagnetic field field acquisition device, which includes a host computer, a slave computer, and sensors; the host computer is connected to the slave computer for controlling the slave computer, capable of receiving natural electromagnetic field data from the slave computer, and generating survey data reflecting the underground electrical structure based on the natural electromagnetic field data; the slave computer is connected to the sensors and capable of generating natural electromagnetic field data based on the natural electromagnetic field signals from the sensors; the sensors include an electric field sensor and a magnetic field sensor, and are configured to: collect the natural electric field and / or magnetic field incident on the ground, and when it is reflected and refracted back to the ground by the underground impedance interface, meet the natural electric field and / or magnetic field incident on the ground at this moment at the sensor, and use the initial time series of the electric / magnetic field intensity after the two interfere and superpose as the sensing data. It can collect first-hand original natural electromagnetic field data with small zero drift, high precision, and high signal-to-noise ratio, which is one of the key links in the high-resolution natural source electromagnetic method exploration technology system.

Description

Technical Field

[0001] The present disclosure relates to the technical field of exploration equipment, and more particularly, to a high-resolution natural source electromagnetic field field acquisition device for fieldwork. Background Art

[0002] Conventional electromagnetic exploration methods are a type of geophysical exploration means that utilize the skin effect phenomenon existing in electromagnetic induction to study underground geological structures, formations, and other geological problems for engineering surveys. It is a volume exploration method. Electromagnetic exploration methods obtain data on the electrical property distribution characteristics of underground rocks and ores through ground measurement and analysis of electromagnetic field data, and combine data on the electromagnetic properties (resistivity, polarizability, magnetic susceptibility, etc.) of rocks and ores, geological, and other geophysical exploration data. Through comprehensive interpretation of various data, relevant problems in geological exploration and engineering surveys are solved.

[0003] The use of natural electromagnetic fields as excitation field sources for geological exploration and engineering surveys can be traced back to the magnetotelluric method (MT, Magnetotelluric) around 1950. Subsequent electromagnetic exploration methods are all results of optimization and improvement based on the principle of the magnetotelluric method, and their exploration accuracy has not been substantially improved.

[0004] Currently, when using natural electromagnetic fields as excitation field sources to carry out geological exploration and engineering survey activities, most efforts are focused on the study of the underground electrical property (resistivity, polarizability) distribution (structure) to solve the main research objectives of stratigraphic distribution and geological structure. However, due to the limited resolution ability of the skin effect volume exploration, only rough information on the underground electrical structure can be obtained, and underground pore media cannot be identified.

[0005] Therefore, there is an urgent need for a high-resolution natural source electromagnetic field field acquisition device based on natural field sources for, for example, the identification of underground pore media. Summary of the Invention

[0006] In view of the deficiencies in the prior art, the present application provides a high-resolution natural source electromagnetic field field acquisition device for fieldwork.

[0007] The high-resolution natural source electromagnetic field field acquisition device provided by the embodiments of the present disclosure includes a host computer, a slave computer, and sensors; wherein,

[0008] The host computer is connected to the slave computer and is used to control the slave computer; it can receive natural electromagnetic field data from the slave computer and generate survey data based on the natural electromagnetic field data;

[0009] The slave computer is connected to the sensors and can generate natural electromagnetic field data based on the sensing data from the sensors;

[0010] The sensor includes an electric field sensor and a magnetic field sensor, and is configured to: collect the natural electric field and / or magnetic field incident on the ground, and when they are reflected and refracted back to the ground at the moment of passing through the underground impedance interface, meet the natural electric field and / or magnetic field incident on the ground at this moment at the sensor, and the initial time series of the synthetic electric field and / or magnetic field intensity obtained by their interference - superposition is used as the sensing data.

[0011] Optionally, the lower computer includes a filtering module, where

[0012] The filtering module is used to suppress the preset power frequency and its harmonics in the sensing data, and also has a low - pass filtering function in a preset frequency band.

[0013] Optionally, the preset power frequency of the filtering module is 50 Hz.

[0014] Optionally, the filtering module can perform multi - level hardware notch filtering and low - pass filtering on the sensing data for no less than 3 levels.

[0015] Optionally, the lower computer includes a multi - channel A / D acquisition module, and a signal amplifier is configured between the multi - channel A / D acquisition module and the filtering module.

[0016] Optionally, the multi - channel A / D acquisition module has 4 to 8 acquisition channels; the multi - channel A / D acquisition module is a 24 - bit or 32 - bit acquisition module.

[0017] Optionally, the lower computer includes a calculation unit, which is used to:

[0018] Perform Fourier transform on the initial time series in the sensing data to obtain the initial spectrum of the initial time series;

[0019] Screen out the dominant frequency components in the initial spectrum; the dominant frequency components are related to the impedance interface and the burial depth of the top / bottom surface of the underground pore medium;

[0020] Based on the synchronous and equal - magnification change of the phase derivative and amplitude derivative of the dominant frequency components, obtain the corresponding relationship between the top or bottom surface of the underground pore medium and the frequency in the dominant frequency components;

[0021] Generate survey data including the corresponding relationship.

[0022] Optionally, the calculation unit can generate survey data including the liquid - containing information of the underground pore medium based on the phase delay of the electric field and / or magnetic field when the electromagnetic wave enters and exits the underground pore medium.

[0023] Optionally, the calculation unit is configured to:

[0024] When the change characteristic of the phase delay amount responds to the following relationship, generate survey data including that the liquid contained in the underground pore medium is formation water:

[0025] When the electromagnetic wave enters the porous medium, the phase delay increases, and when the electromagnetic wave leaves the porous medium, the phase delay decreases;

[0026] When the variation characteristics of the phase delay amount respond to the following relationship, survey data including that the liquid contained in the underground porous medium is crude oil and / or natural gas is generated:

[0027] When the electromagnetic wave enters the porous medium, the phase delay decreases, and when the electromagnetic wave leaves the porous medium, the phase delay increases.

[0028] Optionally, the lower computer includes:

[0029] Real-time time-frequency analysis module, used to output real-time survey data to the host computer;

[0030] The data storage unit is used to store the survey data from the calculation unit as historical survey data, and can output the historical survey data to the host computer in response to a request from the host computer.

[0031] Optional sampling rate is 5000 to 25000 samples / second.

[0032] Optionally, it also includes a power supply module, which can provide power to the lower computer and / or the upper computer; the power supply module includes a battery.

[0033] Optionally, the upper computer can remotely control the lower computer via wireless connection.

[0034] Optionally, the host computer includes a display device, an input device and a wifi module for wirelessly connecting to the slave computer; the display device is used to present the survey information to the user.

[0035] The high-resolution natural source electromagnetic field acquisition equipment provided in the embodiments of the present disclosure combines pseudo-logging processing with single-point wave logging processing; combines electric field data with magnetic field data; and integrates profile results with single-point results. Each method plays its own advantages, and the methods cooperate with each other with their own focus, which comprehensively pushes electromagnetic exploration technology to a new stage.

[0036] In addition, the high-resolution natural source electromagnetic method field acquisition equipment provided in the embodiments of the present disclosure can collect first-hand original natural electromagnetic field data with small zero drift, high precision and high signal-to-noise ratio. As one of the key links in the high-resolution natural source electromagnetic method exploration technology system, it is the basis for the subsequent data processing and interpretation links of the high-resolution natural source electromagnetic method exploration technology, and it is also the fundamental guarantee for whether the exploration results can be achieved in the application of this technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The accompanying drawings included are used to provide a further understanding of the present application and are incorporated into and constitute a part of this specification. The drawings illustrate embodiments of the present application and, together with the following description, are used to explain the principles of the present application.

[0038] Figure 1 Schematic diagram of the instrument module in an embodiment of the present application;

[0039] Figure 2 Schematic diagram of the working mode of each module of the instrument in an embodiment of the present application;

[0040] Figure 3 Schematic diagram of the basic physical principles followed when the electromagnetic field on which the embodiment of the present application relies moves in the underground medium;

[0041] Figure 4 Schematic diagram showing the average amplitude characteristics of the global electromagnetic field intensity;

[0042] Figure 5 Schematic diagram comparing the measured spectrum characteristics of the high-resolution electromagnetic method technology with the new natural electromagnetic field data spectrum characteristic chart board.

[0043] Figure 6 Schematic diagram showing the spectrum characteristics of the new natural electromagnetic field data.

[0044] In the figure, the reference numerals respectively represent:

[0045] 1. Host computer, 2. Slave computer, 3. Sensor, 4. Power supply module;

[0046] 21. Multistage 50 Hz power frequency and its multiple frequency filters;

[0047] 22. Signal amplifier;

[0048] 23. 4 to 8-channel 24-bit A / D converter;

[0049] 24. Calculation unit;

[0050] 25. Real-time time-frequency analysis quality monitoring unit;

[0051] 26. Data storage unit. Detailed implementation manners

[0052] In the description of the embodiments of the present application, those skilled in the art should understand that the embodiments of the present application can be implemented as methods, devices, electronic devices, and computer-readable storage media. Therefore, the embodiments of the present application can be specifically implemented in the following forms: complete hardware, complete software (including firmware, resident software, microcode, etc.), and a combination of hardware and software. In addition, in some embodiments, the embodiments of the present application can also be implemented in the form of a computer program product in one or more computer-readable storage media, and the computer-readable storage media contains computer program code.

[0053] The above-mentioned computer-readable storage media can adopt any combination of one or more computer-readable storage media. Computer-readable storage media include: electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices, or components, or any combination of the above. More specific examples of computer-readable storage media include: portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM), flash memory, optical fibers, compact disc read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any combination of the above. In the embodiments of the present application, the computer-readable storage media can be any tangible medium that contains or stores a program, and the program can be used by or in combination with an instruction execution system, device, or component.

[0054] The computer program code contained in the above-mentioned computer-readable storage media can be transmitted by any suitable medium, including: wireless, wire, optical cable, radio frequency (RF), or any suitable combination of the above.

[0055] The computer program code for performing the operations of the embodiments of the present application can be written in assembly instructions, instruction set architecture (ISA) instructions, machine instructions, machine-related instructions, microcode, firmware instructions, status setting data, integrated circuit configuration data, or in one or more programming languages or combinations thereof. The programming languages include object-oriented programming languages, such as: Java, Smalltalk, C++, and also include conventional procedural programming languages, such as: C language or similar programming languages. The computer program code can be executed entirely on the user's computer, partially on the user's computer, executed as an independent software package, partially on the user's computer and partially on a remote computer, and entirely on a remote computer or server. In the case of a remote computer, the remote computer can be connected to the user's computer through any type of network, including: local area network (LAN) or wide area network (WAN), and can also be connected to an external computer.

[0056] Embodiments of the present application describe the provided methods, apparatuses, and electronic devices through flowcharts and / or block diagrams.

[0057] It should be understood that each block of the flowchart and / or block diagram, and the combinations of blocks in the flowchart and / or block diagram, can be implemented by computer-readable program instructions. These computer-readable program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, thereby producing a machine. These computer-readable program instructions, when executed by a computer or other programmable data processing device, produce an apparatus that implements the functions / operations specified in the blocks of the flowchart and / or block diagram.

[0058] These computer-readable program instructions can also be stored in a computer-readable storage medium that can cause a computer or other programmable data processing device to work in a specific manner. In this way, the instructions stored in the computer-readable storage medium produce an instruction device product that includes the instructions for implementing the functions / operations specified in the blocks of the flowchart and / or block diagram.

[0059] The computer-readable program instructions can also be loaded onto a computer, other programmable data processing device, or other device, such that a series of operation steps are executed on the computer, other programmable data processing device, or other device to produce a computer-implemented process. Thus, the instructions executed on the computer or other programmable data processing device can provide a process for implementing the functions / operations specified in the blocks of the flowchart and / or block diagram.

[0060] The high-resolution natural source electromagnetic field survey technology is based on the correct understanding of the basic physical principles (such as Figure 3 shown) that the electromagnetic field follows when moving in the underground medium under the condition of σ / (ωε) >> 1. Taking the collected natural electromagnetic field data as the research object and based on the four basic characteristics of the natural electromagnetic field moving in the underground medium, starting from the most fundamental aspects of physics and mathematics such as the field data acquisition methods and equipment in the field - modern spectral analysis technology - basic physical principles - solution of partial differential equations, it completely revolutionizes the skin effect principle - short-time sequence analysis - power spectrum calculation - simple superposition denoising - impedance tensor synthesis and other methods of traditional (natural field source and artificial field source) electromagnetic methods. For the first time, it reveals and scientifically understands the new natural electromagnetic field spectral characteristics that are different from the traditional natural electromagnetic field spectral characteristics (such as Figure 4 shown), as well as the new natural electromagnetic field spectral characteristics (such as Figure 5As shown in the figure, a new electromagnetic exploration technology system consisting of five disruptive technologies, six components, and twelve main links has been established. This exploration technology system follows the path of "three combinations", namely: profile simulation. In other words, it is the combination of logging curve processing and single-point wave logging processing; the combination of electric field data and magnetic field data; the integration of profile results and single-point results. Each method gives full play to its own advantages, cooperates with each other, and has its own focus, pushing the electromagnetic exploration technology to a new stage in an all-round way.

[0061] In view of this, one of the keys to the above high-resolution natural source electromagnetic field exploration technology lies in "high-quality acquisition of natural electromagnetic field field data in the wild". Collecting the first-hand original natural electromagnetic field data with small zero drift, high precision, and high signal-to-noise ratio is the basis for the subsequent data processing and interpretation links of this technology, and is the fundamental guarantee for whether exploration results can be achieved in the application of this technology. Therefore, the present disclosure provides a high-resolution natural source electromagnetic method field acquisition device as described in the embodiments, which is used to collect the first-hand original natural electromagnetic field data with small zero drift, high precision, and high signal-to-noise ratio, which is the basis for the subsequent data processing and interpretation links of the above technology, and is the fundamental guarantee for whether exploration results can be achieved in the application of the above technology.

[0062] The high-resolution natural source electromagnetic method field acquisition device provided by the embodiments of the present disclosure includes the basic configuration shown in Figure 1 the figure: a host computer, a slave computer, and sensors; among them,

[0063] The host computer is connected to the slave computer for controlling the slave computer; it can receive the exploration data from the slave computer and generate exploration information based on the exploration data;

[0064] The slave computer is connected to the sensors and can generate exploration data based on the sensing data from the sensors;

[0065] The sensors include an electric field sensor and a magnetic field sensor, and are configured to: collect the natural electric field and / or magnetic field incident on the ground, and when it is reflected and refracted back to the ground by the underground impedance interface, meet the natural electric field and / or magnetic field incident on the ground at this moment at the sensor, and the initial time series of the combined electric field and / or magnetic field intensity obtained by the interference and superposition of the two is used as the sensing data.

[0066] In a preferred embodiment, as shown in Figure 1 the figure, the slave computer includes a filtering module, where

[0067] The filtering module is used to suppress the preset power frequency and the multiple frequencies of the preset power frequency in the sensing data, and also includes a low-pass filtering function for a preset frequency band. Typically, the preset power frequency of the filtering module is 50 Hz. That is Figure 1 the multi-stage 50 Hz power frequency and its multiple frequency filters 21 shown in the figure.

[0068] In a typical embodiment, the filtering module is capable of performing multi-level hardware notch filtering and low-pass filtering on the sensing data with no less than three levels.

[0069] Multi-level filtering of not less than three levels for 50 Hz power frequency and its harmonics: Through hardware notch filtering of more than three levels, the electrical and magnetic signals from the sensor are effectively suppressed for 50 Hz power frequency and its harmonic interference before entering the amplifier for amplification.

[0070] Furthermore, according to the highest frequency to be collected, the filtering module is capable of performing first comb filtering processing and low-pass filtering processing. Among them, the first comb filtering processing is to suppress the power frequency and its harmonics; the low-pass filtering is to filter out the frequency components higher than the highest frequency to be collected. The power frequency refers to the rated frequency adopted by the equipment of the power system, industrial electrical equipment, and civil electrical equipment. Exemplarily, the power frequency is 50 Hz. In some optional cases, regardless of the burial depth of the detection object and the sampling rate during data collection, it is necessary to pre-set the intensity of suppressing the power frequency and its harmonic components. In some optional cases, according to the highest frequency to be collected, it is necessary to pre-set low-pass filtering to suppress the frequency components higher than the highest frequency to be collected.

[0071] In addition, the high-resolution natural source electromagnetic method field acquisition equipment in the above embodiment is divided into upper and lower computer controls. Preferably, a commercial notebook computer can be used as the control terminal (upper computer) of the instrument, which is beneficial to the light weight of the instrument, and is also beneficial to the encapsulation of the instrument, and is beneficial to dust prevention, waterproofing, heat dissipation, etc.

[0072] In addition, the sensors in the equipment can be deployed in the field or at sea.

[0073] In a preferred embodiment, the lower computer includes a multi-channel A / D acquisition module, and a signal amplifier is provided between the multi-channel A / D acquisition module and the filtering module. Preferably, the multi-channel A / D acquisition module has 4 to 8 acquisition channels; the multi-channel A / D acquisition module is a 24-bit or 32-bit acquisition module. As Figure 1 shown is a 4 to 8-channel 24-bit A / D converter (acquisition card) 23.

[0074] In a preferred embodiment, the lower computer includes a calculation unit 24 for:

[0075] Performing a Fourier transform on the initial time series in the sensing data to obtain the initial spectrum of the initial time series;

[0076] Screening out the dominant frequency components in the initial spectrum; the dominant frequency components are related to the impedance interface and the burial depth of the top / bottom surface of the underground pore medium;

[0077] Based on the synchronous and equal magnification changes of the phase derivative and amplitude derivative of the dominant frequency component, the corresponding relationship between the top or bottom surface of the underground pore medium and the frequency in the dominant frequency component is obtained;

[0078] Generate survey data including the corresponding relationship.

[0079] In a preferred embodiment, the calculation unit can generate survey data including the liquid content information of the underground pore medium based on the phase delay amount of the electric field and / or magnetic field when the electromagnetic wave enters and exits the underground pore medium.

[0080] In a preferred embodiment, the calculation unit is configured as:

[0081] When the change characteristic of the phase delay amount responds to the following relationship, generate survey data including that the liquid content of the underground pore medium is formation water:

[0082] When the electromagnetic wave enters the pore medium, the phase delay amount increases, and when the electromagnetic wave exits the pore medium, the phase delay amount decreases;

[0083] When the change characteristic of the phase delay amount responds to the following relationship, generate survey data including that the liquid content of the underground pore medium is crude oil and / or natural gas:

[0084] When the electromagnetic wave enters the pore medium, the phase delay amount decreases, and when the electromagnetic wave exits the pore medium, the phase delay amount increases.

[0085] In addition, for the above phase delay amount, it at least satisfies:

[0086]

[0087] Wherein, is the phase delay amount when the electromagnetic wave enters / exits the underground pore medium; z is the propagation distance of the electromagnetic wave from the ground to the top or bottom surface of the underground pore medium; σ is the conductivity of the underground pore medium; μ is the relative magnetic permeability of the underground pore medium; ω is the angular frequency of the electromagnetic wave: ω = 2πf, and f is the frequency of the electromagnetic wave.

[0088] According to the embodiments of the present disclosure, the amplitude derivative of the dominant frequency component at least satisfies any one of the following expressions, that is:

[0089]

[0090]

[0091] Among them, a is an exponential function of σ and μ, and a is a linear function of z; b is an exponential function of f. z is the propagation distance of the electromagnetic wave from the ground to the top or bottom surface of the underground pore medium; σ is the conductivity of the underground pore medium; μ is the relative magnetic permeability of the underground pore medium; f is the electromagnetic wave frequency.

[0092] According to the embodiments of the present disclosure, the phase derivative of the dominant frequency component satisfies at least any one of the following expressions, that is:

[0093]

[0094]

[0095] Among them, a is an exponential function of σ and μ, and a is a linear function of z. z is the propagation distance of the electromagnetic wave from the ground to the top or bottom surface of the underground pore medium; σ is the conductivity of the underground pore medium; μ is the relative magnetic permeability of the underground pore medium; f is the electromagnetic wave frequency; t is the propagation time of the electromagnetic wave from the ground to the top or bottom surface of the underground pore medium.

[0096] According to the embodiments of the present disclosure, the initial spectrum includes the frequency, real part, imaginary part, amplitude, and phase of the electric field and / or magnetic field.

[0097] According to the embodiments of the present disclosure, the time length of the Fourier transform is positively correlated with the burial depth of the underground pore medium to be identified.

[0098] For the aforementioned sensor, the initially collected data may include the moment when the natural electric field and / or magnetic field incident on the ground is reflected and refracted back to the ground through the underground impedance interface and meets at the sensor, and the synthetic electric field intensity obtained by the interference and superposition of the two, or it may also be the synthetic magnetic field intensity, or it may simultaneously be the intensities of the electric field and the magnetic field. In the specific implementation process, the type of the initial signal can be freely selected according to the requirements of the survey task. It should be noted that when jointly collecting the intensities of the magnetic field and the electric field, the lowest frequency collected is the lower limit of the frequency that the magnetic sensor can receive, so as to calculate the Cagniard resistivity, so that when inverting the underground geoelectric structure, a larger survey depth can be achieved. When collecting the intensity of the magnetic field or the electric field alone, the lowest frequency collected can optionally take any value between 1 and 10 Hz for calculation. In an alternative embodiment, the frequency of the initial signal is greater than 0.1 Hz and less than or equal to 10,000 Hz.

[0099] It should be understood that the above phase delay amount is based on the dispersion phenomenon. The study of the dispersion phenomenon focuses on the relationships between parameters such as the phase shift, attenuation, and propagation speed of electromagnetic waves and the electromagnetic wave frequency and the liquid resistivity contained. As long as the corresponding harmonic index and higher-order harmonic index of the pore medium reach a recognizable level, we can identify the pore medium. Obviously, when judging the (oil-gas-water) in the reservoir based on the dispersion principle, its resolution ability is not limited by the 1 / 4 wavelength limit of electromagnetic waves. Due to the different liquids contained in the pore medium, there is a significantly characteristic response relationship between the amplitude derivative and the phase derivative when the electromagnetic wave enters and leaves the pore medium. The difference in the phase delay amount between the pore medium containing water and the pore medium containing crude oil (natural gas) "combination" can effectively predict the liquid contained in the pore medium. In practice, the frequency resolution during data collection and analysis can be used as a criterion for measuring the resolution ability of the technology of this application.

[0100] In a typical embodiment, the working mode and working process of the acquisition device are as Figure 2 shown:

[0101] The natural electric field or magnetic field, after entering the ground, reflects or refracts at the underground impedance interface (which is the position to be surveyed), and returns to the ground;

[0102] Meanwhile, other natural electric fields or magnetic fields that are about to enter the ground interfere and superpose with the aforementioned electric / magnetic field that returns to the ground on the ground, forming the natural electromagnetic field signal required in this application, and being received and collected by the sensor in the device.

[0103] The sensor transmits the collected data as sensing data to the lower computer.

[0104] The lower computer processes the sensing data, including but not limited to filtering, signal amplification, A / D conversion, calculation, time-frequency analysis, quality monitoring, or storage, etc. And it can respond to the request of the upper computer and transmit the immediate or previously stored natural electromagnetic field data to the upper computer.

[0105] Based on the received natural electromagnetic field data, the upper computer generates intuitive survey data for the user side, and this survey data is mainly used to reflect the underground electrical structure, such as formation water, oil, gas, etc.

[0106] In the preferred embodiment, as Figure 1 shown, the lower computer further includes:

[0107] A real-time time-frequency analysis module 25, which is used to output real-time survey data to the upper computer;

[0108] A data storage unit 26 is configured to store the survey data from the computing unit as historical survey data, and is capable of retrieving and outputting the historical survey data to the host computer in response to a request from the host computer. Typically, the data storage unit 26 may specifically be an electronic storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination thereof.

[0109] In a preferred embodiment, the sampling rate is from 5000 to 25000 samples per second.

[0110] In a preferred embodiment, it further includes a power supply module 4 capable of supplying power to the lower computer and / or the host computer; the power supply module includes a battery. Specifically, the power supply module may be a 24V power bank, a portable lithium battery, etc.

[0111] In a preferred embodiment, the host computer wirelessly connects to and remotely controls the lower computer.

[0112] In a preferred embodiment, the host computer includes a display device, an input device, and a Wi-Fi module for wirelessly connecting to the lower computer; the display device is used to present survey information to the user.

[0113] Illustratively, the survey information may include an exploration harmonic index curve and a phase delay curve, or similar charts, graphs, tables, text information, etc. that can directly or indirectly obtain the survey results.

[0114] In a typical embodiment, the host computer is a commercial portable computer. The computer wirelessly remotely controls the lower computer via Wi-Fi to control, monitor the quality of, and perform real-time data transmission and storage for the lower computer; a 24V commercial power bank is connected to the lower computer through a plug to supply power to the lower computer and the electric / magnetic sensors; the electric / magnetic sensors are connected to the instrument through a cable / plug.

[0115] Filtering of not less than three levels of multi-level 50 Hz power frequency and its multiples: Through hardware notch filtering of more than 3 levels, the electrical and magnetic signals from the sensors are suppressed for 50 Hz power frequency and its multiple interferences before entering the amplifier for amplification.

[0116] The lower computer is separated from the power supply. This facilitates their respective portability and management. A large-capacity 24V commercial power bank is configured to ensure the working time for field collection.

[0117] Controlled by upper and lower computers, with a commercial notebook computer serving as the control unit for the lower computer, which is beneficial for the instrument to be lightweight, and also beneficial for instrument encapsulation, dust prevention, waterproofing, heat dissipation, etc.

[0118] In a typical embodiment, the provided high-resolution natural source electromagnetic method field acquisition device has the following technical specifications:

[0119] 1. Frequency band range: 0.1-10K Hz;

[0120] 2. Instrument sampling rate: 5000-25K samples / second, the sampling rate is adjustable;

[0121] At a single sampling rate of 3.25k samples / second, it can continuously collect and record for 60 minutes;

[0122] 4. During the data collection period within one hour, the instrument zero drift is less than 20nv

[0123] And the following table:

[0124]

[0125]

[0126] Table 1 Main technical indicators of the instrument

[0127] In summary, the high-resolution natural source electromagnetic field acquisition equipment provided in the embodiment of the present application combines pseudo-logging processing with single-point wave logging processing; combines electric field data with magnetic field data; and integrates profile results with single-point results. Each method plays its own advantages, and the methods cooperate with each other and have their own focus, which comprehensively pushes electromagnetic exploration technology to a new stage.

[0128] In addition, the high-resolution natural source electromagnetic method field acquisition equipment provided in the embodiments of the present disclosure can collect first-hand original natural electromagnetic field data with small zero drift, high precision and high signal-to-noise ratio. As one of the key links in the high-resolution natural source electromagnetic method exploration technology system, it is the basis for the subsequent data processing and interpretation links of the high-resolution natural source electromagnetic method exploration technology, and it is also the fundamental guarantee for whether the exploration results can be achieved in the application of this technology.

[0129] The above is only a specific implementation of the embodiment of the present application, but the protection scope of the embodiment of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or replacements within the technical scope disclosed in the embodiment of the present application, which should be included in the protection scope of the embodiment of the present application. Therefore, the protection scope of the embodiment of the present application shall be based on the protection scope of the claims.

Claims

1. A high-resolution natural source electromagnetic method field acquisition device, characterized in that, It includes a host computer, a slave computer, and sensors; among them, The host computer is connected to the slave computer and is used to control the slave computer. It can receive the natural electromagnetic field data from the slave computer and generate survey data reflecting the underground electrical structure based on the natural electromagnetic field data; The slave computer is connected to the sensors and can generate natural electromagnetic field data based on the sensing data from the sensors; The sensors include electric field sensors and / or magnetic field sensors and are configured to: collect the natural electric field and / or magnetic field incident on the ground, and when they are reflected and refracted back to the ground at the moment of passing through the underground impedance interface, meet the natural electric field and / or magnetic field incident on the ground at this moment at the sensors. The initial time series of the combined electric field and / or magnetic field intensity obtained after their interference and superposition is used as the sensing data.

2. The high-resolution natural source electromagnetic method field acquisition device according to claim 1, characterized in that, The slave computer includes a pre-filtering module, where The filtering module is used to suppress the preset power frequency and its harmonics in the sensing data, and the filtering module also has a low-pass filtering function in a preset frequency band.

3. The high-resolution natural source electromagnetic method field acquisition device according to claim 2, wherein The preset power frequency of the filtering module is 50 Hz.

4. The high-resolution natural source electromagnetic method field acquisition device according to claim 2 or as described above, characterized in that, The filtering module can perform multi-stage hardware notch filtering and low-pass filtering on the sensing data for no less than 3 levels.

5. The high-resolution natural source electromagnetic method field acquisition device according to claim 2, wherein The slave computer includes a multi-channel A / D acquisition module, and a signal amplifier is configured between the multi-channel A / D acquisition module and the filtering module.

6. The high-resolution natural source electromagnetic method field acquisition device according to claim 5, characterized in that The multi-channel A / D acquisition module has 4 to 8 acquisition channels; the multi-channel A / D acquisition module is a 24-bit or 32-bit acquisition module.

7. The high-resolution natural source electromagnetic method field acquisition device according to any one of claims 1 to 6, characterized in that, The slave computer includes a calculation unit for: Performing Fourier transform on the initial time series in the sensing data to obtain the initial spectrum of the initial time series; Screening out the dominant frequency components in the initial spectrum; the dominant frequency components are related to the buried depth of the underground impedance interface, the top or bottom surface of the underground pore medium; Based on the synchronous and equal magnification changes of the phase derivative and amplitude derivative of the dominant frequency components, obtaining the corresponding relationship between the impedance interface, the top or bottom surface of the underground pore medium and the frequency in the dominant frequency components; Generating the survey data including the corresponding relationship.

8. The high-resolution natural source electromagnetic method field acquisition device according to claim 7, characterized in that, The calculation unit can generate survey data including the liquid content information of the underground pore medium based on the phase delay amount of the electric field and / or magnetic field when the electromagnetic wave enters and exits the underground pore medium.

9. The high-resolution natural source electromagnetic method field acquisition device according to claim 8, characterized in that, The calculation unit is configured to: When the change characteristics of the phase delay amount respond to the following relationship, generate survey data including that the liquid content of the underground pore medium is formation water: When the electromagnetic wave enters the pore medium, the phase delay amount increases, and when the electromagnetic wave leaves the pore medium, the phase delay amount decreases; When the change characteristics of the phase delay amount respond to the following relationship, generate survey data including that the liquid content of the underground pore medium is crude oil and / or natural gas: When the electromagnetic wave enters the pore medium, the phase delay amount decreases, and when the electromagnetic wave leaves the pore medium, the phase delay amount increases.

10. The high-resolution natural source electromagnetic method field acquisition device according to claim 7, characterized in that, The slave computer includes: A real-time time-frequency analysis module for outputting the real-time natural electromagnetic field data to the host computer; A data storage unit is configured to store the natural electromagnetic field data from the computing unit as historical natural electromagnetic field data, and is capable of screening and outputting the required historical natural electromagnetic field data to the host computer in response to a request from the host computer.

11. The high-resolution natural source electromagnetic method field acquisition device according to claim 7, characterized in that, The sampling rate is from 5000 to 25000 samples per second.

12. The high-resolution natural source electromagnetic method field acquisition device according to claim 1, characterized in that, It further includes a power supply module that can supply power to the lower computer and / or the host computer; the power supply module includes an external battery.

13. The high-resolution natural source electromagnetic method field acquisition device according to claim 1, characterized in that The host computer wirelessly connects to and remotely controls the lower computer.

14. The high-resolution natural source electromagnetic method field acquisition device according to claim 13, characterized in that, The host computer includes a display device, an input device, and a wifi module for wirelessly connecting to the lower computer; the display device is used to present the survey data reflecting the underground electrical structure to the user.

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