High-resolution natural source electromagnetic method field acquisition equipment

Abstract

The invention relates to high-resolution natural source electromagnetic method field acquisition equipment which comprises an upper computer, a lower computer and a sensor. The upper computer is connected with the lower computer, is used for controlling the lower computer, can receive the natural electromagnetic field data from the lower computer, and generates survey data reflecting an underground electrical structure based on the natural electromagnetic field data; the lower computer is connected with the sensor and can generate natural electromagnetic field data based on a natural electromagnetic field signal from the sensor; the sensor comprises an electric field sensor and a magnetic field sensor, and is configured to collect a natural electric field and / or magnetic field entering the underground and encounter the natural electric field and / or magnetic field entering the underground at the moment when the natural electric field and / or magnetic field enters the underground and is reflected and refracted back to the ground through an underground electrical impedance interface; and an initial time sequence of the electric / magnetic field intensity after interference-superposition is used as sensing data. First-hand original natural electromagnetic field data with small null drift, high precision and high signal-to-noise ratio can be collected, and the first-hand original natural electromagnetic field data serves as one of key links of a 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 in particular to a high-resolution natural source electromagnetic field acquisition equipment. Background Art

[0002] Conventional electromagnetic survey method is a kind of geophysical exploration method that uses the skin effect of electromagnetic induction to study underground geological structures, structures and other geological problems, and conduct engineering surveys. It is a volume exploration method. The electromagnetic survey method obtains underground rock and ore electrical distribution characteristics through the measurement and analysis of electromagnetic field data on the ground, and combines rock and ore electromagnetic (resistivity, polarizability, magnetic susceptibility, etc.) property data, geological and other geophysical data, and solves geological exploration and engineering exploration related problems through comprehensive interpretation of multiple data.

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

[0004] At present, geological exploration and engineering survey activities using natural electromagnetic fields as excitation sources are mostly devoted to the study of underground electrical properties (resistivity, polarizability) distribution (structure), with the main research objectives being to solve the stratum distribution and geological structure. However, due to the limited resolution of the skin effect volume exploration, only rough information on the underground electrical structure can be obtained, and the underground porous media cannot be identified.

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

[0006] In view of the shortcomings of the prior art, the present application provides a high-resolution natural source electromagnetic field acquisition equipment.

[0007] The high-resolution natural source electromagnetic field acquisition equipment provided by the embodiment of the present disclosure includes a host computer, a slave computer and a sensor; wherein:

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

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

[0010] The sensor includes an electric field sensor and a magnetic field sensor, and is configured to collect natural electric fields and / or magnetic fields incident on the ground. When the natural electric fields and / or magnetic fields incident on the ground are reflected and refracted back to the ground through the underground electrical impedance interface, they meet at the sensor and the initial time series of the synthetic electric field and / or magnetic field strength obtained by the interference and superposition of the two is used as the sensing data.

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

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

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

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

[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 filter 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 computing unit for:

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

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

[0020] Based on the synchronous and equal-multiplication changes of the phase derivative and amplitude derivative of the dominant frequency component, the corresponding relationship between the top surface or bottom surface of the underground porous medium and the frequency in the dominant frequency component is obtained;

[0021] Survey data including the correspondence is generated.

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

[0023] Optionally, the computing unit is configured as:

[0024] 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 formation water is generated:

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

[0038] Figure 1 A schematic diagram of an instrument module according to an embodiment of the present application is shown;

[0039] Figure 2 A schematic diagram showing the working mode of each module of the instrument in the embodiment of the present application is shown;

[0040] Figure 3 A schematic diagram showing the basic physical principle followed by the electromagnetic field according to the embodiment of the present application when moving in an underground medium;

[0041] Figure 4 shows the global average amplitude characteristic diagram of electromagnetic field strength;

[0042] Figure 5 A comparison chart of the spectrum characteristics of the high-resolution electromagnetic method and the new natural electromagnetic field data is shown.

[0043] Figure 6 A new natural electromagnetic field data spectrum feature map is shown.

[0044] The reference numerals in the figure represent respectively:

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

[0046] 21. Multi-stage 50 Hz power frequency and its frequency doubling filter;

[0047] 22.Signal amplifier;

[0048] 23.4 to 8 channel 24-bit A / D converter;

[0049] 24. Computing unit;

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

[0051] 26. Data storage unit. DETAILED DESCRIPTION

[0052] In the description of the embodiments of the present application, it should be understood by those skilled in the art 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.), 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 medium contains computer program code.

[0053] The above-mentioned computer-readable storage medium may 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 devices, or any combination of the above. More specific examples of computer-readable storage media include: portable computer disks, hard disks, random access memories (RAM), read-only memories (ROM), erasable programmable read-only memories (EPROM), flash memories (Flash Memory), optical fibers, compact disk read-only memories (CD-ROM), optical storage devices, magnetic storage devices or any combination of the above. In an embodiment of the present application, a computer-readable storage medium may be any tangible medium containing or storing a program, which may be used by or in combination with an instruction execution system, device, or device.

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

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

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

[0057] It should be understood that each box in the flowchart and / or block diagram and the combination of boxes 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 to produce a machine, and these computer-readable program instructions are executed by a computer or other programmable data processing device to produce a device that implements the functions / operations specified by the boxes in the flowchart and / or block diagram.

[0058] These computer-readable program instructions may also be stored in a computer-readable storage medium that enables 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 including functions / operations specified in the blocks in the flowchart and / or block diagram.

[0059] Computer-readable program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other device, so that a series of operational steps are performed on the computer, other programmable data processing apparatus, or other device to produce a computer-implemented process, thereby enabling the instructions executed on the computer or other programmable data processing apparatus to provide a process for implementing the functions / operations specified in the blocks in the flowchart and / or block diagram.

[0060] High-resolution natural source electromagnetic field survey technology is based on the scientific and correct understanding of the basic physical principles (such as Figure 3 As shown in the figure, the collected natural electromagnetic field data are used as the research object, and the four basic characteristics of the movement of natural electromagnetic fields in underground media are used as the basis. Starting from the most basic physics and mathematics such as field data collection methods and equipment - modern spectrum analysis technology - basic physics principles - partial differential equation solution, the traditional (natural field source and artificial field source) electromagnetic method technology, such as skin effect principle - short time series analysis - power spectrum calculation - simple superposition denoising - impedance tensor synthesis, is completely transformed. For the first time, the natural electromagnetic field spectrum characteristics (such as Figure 4 as shown), new natural electromagnetic field spectrum characteristics (such as Figure 5As shown in the figure, a new electromagnetic exploration technology system consisting of five disruptive technologies, six major 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 combines simulated logging processing with single-point wave logging processing; combines electric field data with magnetic field data; integrates profile results with single-point results, and each method plays its own advantages, cooperates with each other, and has its own focus, which has comprehensively pushed electromagnetic exploration technology to a new stage.

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

[0062] The high-resolution natural source electromagnetic field acquisition equipment provided by the embodiment of the present disclosure includes: Figure 1 The basic configuration shown: host computer, slave computer and sensor; among them,

[0063] The upper computer is connected to the lower computer and is used to control the lower computer; it can receive survey data from the lower computer and generate survey information based on the survey data;

[0064] The lower computer is connected to the sensor and can generate survey data based on the sensing data from the sensor;

[0065] The sensor includes an electric field sensor and a magnetic field sensor, and is configured to collect natural electric fields and / or magnetic fields incident on the ground. When the natural electric fields and / or magnetic fields incident on the ground are reflected and refracted back to the ground through the underground electrical impedance interface, they meet at the sensor and the initial time series of the synthetic electric field and / or magnetic field strength obtained by the interference and superposition of the two is used as the sensing data.

[0066] In a preferred embodiment, Figure 1 As shown, the lower computer includes a filtering module, wherein:

[0067] The filter module is used to suppress the preset power frequency and the multiple frequency of the preset power frequency in the sensor data, and also includes a low-pass filter function of a preset frequency band. Typically, the preset power frequency of the filter module is 50 Hz. Figure 1 The multi-stage 50 Hz power frequency and its multiplier filter 21 is shown in FIG.

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

[0069] At least three levels of multi-level 50 Hz power frequency and its multiple frequency filtering: Through more than 3 levels of hardware notch filtering, the electrical and magnetic signals from the sensor can effectively suppress the 50 Hz power frequency and its multiple frequency interference before entering the amplifier for amplification.

[0070] Furthermore, according to the highest frequency to be collected, the filtering module can perform a first comb filtering process and a low-pass filtering process. Among them, the first comb filtering process is to suppress the power frequency and the multiples of the power frequency; the low-pass filtering is to filter the frequency components higher than the highest frequency to be collected. The power frequency refers to the rated frequency used 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-suppress the intensity of the power frequency and its multiples. In some optional cases, it is necessary to pre-low-pass filter according to the highest frequency to be collected to suppress the frequency components higher than the highest frequency to be collected.

[0071] In addition, the high-resolution natural source electromagnetic field acquisition equipment in the above embodiment is divided into upper and lower computer controls. It is preferred to use a commercial laptop computer as the control end (upper computer) of the instrument, which is conducive to the lightweight of the instrument, and is also conducive to instrument packaging, dust prevention, waterproofing, heat dissipation, etc.

[0072] In addition, sensors in the device 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 filter 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. Figure 1 Shown is a 4 to 8 channel 24-bit A / D converter (capture card) 23.

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

[0075] Perform Fourier transform on the initial time series in the sensor data to obtain the initial spectrum of the initial time series;

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

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

[0078] Survey data including the correspondence is generated.

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

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

[0081] 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 formation water is generated:

[0082] 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;

[0083] 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:

[0084] 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.

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

[0086]

[0087] in, is the phase delay of the electromagnetic wave when entering / exiting the underground porous medium; z is the propagation distance of the electromagnetic wave from the ground to the top or bottom surface of the underground porous medium; σ is the electrical conductivity of the underground porous medium; μ is the relative magnetic permeability of the underground porous medium; ω is the angular frequency of the electromagnetic wave: ω=2πf, f is the frequency of the electromagnetic wave.

[0088] According to the embodiment of the present disclosure, the amplitude derivative of the dominant frequency component satisfies at least one of the following expressions, namely:

[0089]

[0090]

[0091] Wherein, a is an exponential function of σ and μ, 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 porous medium; σ is the electrical conductivity of the underground porous medium; μ is the relative magnetic permeability of the underground porous medium; and f is the frequency of the electromagnetic wave.

[0092] According to the embodiment of the present disclosure, the phase derivative of the dominant frequency component satisfies at least one of the following expressions, namely:

[0093]

[0094]

[0095] Wherein, 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 porous medium; σ is the electrical conductivity of the underground porous medium; μ is the relative magnetic permeability of the underground porous medium; f is the frequency of the electromagnetic wave; and t is the propagation time of the electromagnetic wave from the ground to the top or bottom surface of the underground porous medium.

[0096] According to an embodiment 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 an embodiment of the present disclosure, the time length of the Fourier transform is positively correlated with the burial depth of the underground porous medium to be identified.

[0098] For the aforementioned sensor, the collected initial data may include the moment when the underground electrical impedance interface is reflected and refracted back to the ground, and the natural electric field and / or magnetic field incident underground at the moment meets at the sensor, and the synthetic electric field strength obtained by the interference-superposition of the two may also be the synthetic magnetic field strength, or the strength of the electric field and magnetic field at the same time. In the specific implementation process, the type of initial signal can be freely selected according to the needs of the survey task. It should be noted that when the strength of the magnetic field and the electric field are jointly collected, the minimum frequency collected is the lower limit of the frequency that the magnetic sensor can receive as the collection lower limit, so as to calculate the Garnier resistivity, so as to have a larger survey depth when inverting the underground geoelectric structure. When the strength of the magnetic field or electric field is collected alone, the minimum frequency collected can optionally take any value in 1-10 Hz for calculation. In an optional embodiment, the frequency of the initial signal is greater than 0.1 Hz and less than or equal to 10000 Hz.

[0099] It should be understood that the above-mentioned phase delay is based on the dispersion phenomenon. The dispersion phenomenon studies the relationship between the phase shift, attenuation, propagation speed and other parameters of electromagnetic waves and the frequency of electromagnetic waves and the resistivity of the liquid contained. As long as the harmonic index and high-order harmonic index corresponding to the porous medium reach the level that can be identified, we can identify the porous medium. Obviously, the resolution ability of judging (oil-gas-water) in the reservoir based on the dispersion principle is not limited by the 1 / 4 wavelength limit of the electromagnetic wave. Due to the different liquids contained in the porous medium, there is a characteristic phase delay difference response relationship between the amplitude derivative and the phase derivative of the electromagnetic wave when entering and leaving the porous medium. The difference in phase delay between the "assembly" of water-containing porous media and crude oil (natural gas)-containing porous media can effectively predict the liquid contained in the porous medium. In practice, the frequency resolution during data acquisition and analysis can be used as a standard for measuring the resolution ability of the technology of this application.

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

[0101] The natural electric or magnetic field, after entering the ground, is reflected or refracted at the underground impedance interface (that is, the location to be surveyed) and returns to the ground;

[0102] At the same time, other natural electric or magnetic fields that will be incident on the ground interfere and overlap with the electric / magnetic fields returning to the ground, forming the natural electromagnetic field signals required in this application, and are received and collected by the sensors in the equipment.

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

[0104] The lower computer processes the sensor 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 real-time or previously stored natural electromagnetic field data to the upper computer.

[0105] Based on the received natural electromagnetic field data, the host computer generates intuitive, user-oriented survey data, which is mainly used to reflect the underground electrical structure, such as formation water, oil, gas, etc.

[0106] In a preferred embodiment, if Figure 1 The lower machine shown also includes:

[0107] Real-time time-frequency analysis module 25, used to output real-time survey data to the host computer;

[0108] The data storage unit 26 is used to store the survey data from the computing unit as historical survey data, and can retrieve and output the historical survey data to the host computer in response to the request of the host computer. Typically, the data storage unit 26 can 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 5000 to 25000 samples / second.

[0110] In a preferred embodiment, a power supply module 4 is also included, which can supply power to the lower computer and / or the upper computer; the power supply module includes a battery. Specifically, the power supply module can be a 24-hour power bank, a portable lithium battery, etc.

[0111] In a preferred embodiment, the upper computer controls the lower computer via wireless connection and remote control.

[0112] In a preferred embodiment, 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.

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

[0114] In a typical embodiment, the host computer is a commercial portable computer. The computer controls the slave computer wirelessly via wifi to control, monitor quality, and transmit and store data in real time; a 24V commercial power bank is connected to the slave computer via a plug to power the slave computer and the electric / magnetic sensor; the electric / magnetic sensor is connected to the instrument via a cable / plug.

[0115] At least three levels of multi-level 50 Hz power frequency and its multiple frequency filtering: Through more than 3 levels of hardware notch filtering, the electrical and magnetic signals from the sensor are first suppressed against the 50 Hz power frequency and its multiple frequency interference before entering the amplifier for amplification.

[0116] The lower computer is separated from the power supply, making it easy to carry and manage them separately. A large-capacity 24V commercial power bank is configured to ensure the working time of field collection.

[0117] The control is divided into upper and lower computers, with a commercial laptop computer serving as the control unit of the lower computer, which is conducive to the instrument's portability, instrument packaging, dustproofing, waterproofing, and heat dissipation.

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

[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 field acquisition equipment, characterized in that: It includes a host computer, a slave computer and a sensor; among them, The upper computer is connected to the lower computer, used to control the lower computer, and can receive natural electromagnetic field data from the lower computer, and generate survey data reflecting underground electrical structure based on the natural electromagnetic field data; The lower computer is connected to the sensor and can generate natural electromagnetic field data based on the sensing data from the sensor; The sensor includes an electric field sensor and / or a magnetic field sensor, and is configured to: collect natural electric fields and / or magnetic fields incident on the ground, and at the moment when they are reflected and refracted back to the ground through the underground electrical impedance interface, they 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 strength obtained by the interference and superposition of the two is used as the sensing data.

2. The high-resolution natural source electromagnetic field acquisition equipment according to claim 1 is characterized in that: The lower computer includes a pre-filter module, wherein: The filtering module is used to suppress the preset power frequency and the multiple frequency of the preset power frequency in the sensing data, and the filtering module also has a low-pass filtering function of a preset frequency band.

3. The high-resolution natural source electromagnetic field acquisition equipment according to claim 2 is characterized in that: The preset operating frequency of the filter module is 50 Hz.

4. The high-resolution natural source electromagnetic field acquisition equipment according to claim 2, characterized in that: The filtering module can perform no less than 3 levels of multi-level hardware notch filtering and low-pass filtering on the sensor data.

5. The high-resolution natural source electromagnetic field acquisition equipment according to claim 2 is characterized in that: 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 filter module.

6. The high-resolution natural source electromagnetic field acquisition equipment according to claim 5 is 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 field acquisition equipment according to any one of claims 1 to 6, characterized in that: The lower computer includes a computing unit, which is used for: Performing Fourier transformation on the initial time series in the sensing data to obtain an initial spectrum of the initial time series; Screening a dominant frequency component in the initial frequency spectrum; the dominant frequency component is related to the burial depth of the underground electrical impedance interface, the top surface or the bottom surface of the underground porous medium; Based on the synchronous and equal-rate changes of the phase derivative and the amplitude derivative of the dominant frequency component, the corresponding relationship between the electrical impedance interface, the top surface or the bottom surface of the underground porous medium and the frequency in the dominant frequency component is obtained; The survey data including the corresponding relationship is generated.

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

9. The high-resolution natural source electromagnetic field acquisition equipment according to claim 8, characterized in that: The computing unit is configured as follows: When the variation characteristic of the phase delay amount responds to the following relationship, survey data including that the liquid contained in the underground porous medium is formation water is generated: 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; When the variation characteristic of the phase delay amount responds 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: 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.

10. The high-resolution natural source electromagnetic field acquisition equipment according to claim 7, characterized in that: The lower computer comprises: A real-time time-frequency analysis module, used for outputting the real-time natural electromagnetic field data to the host computer; The data storage unit is used to store the natural electromagnetic field data from the calculation unit as historical natural electromagnetic field data, and can screen and output 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 field acquisition equipment according to claim 7, characterized in that: The sampling rate is 5000 to 25000 samples / second.

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

13. The high-resolution natural source electromagnetic field acquisition equipment according to claim 1, characterized in that: The upper computer is connected to and remotely controls the lower computer via wireless.

14. The high-resolution natural source electromagnetic field acquisition equipment 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 slave computer; the display device is used to present the survey data reflecting the underground electrical structure to the user.

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