A borehole time domain electromagnetic far detector and method

Abstract

The application discloses a borehole time domain electromagnetic far detection device and method, which comprises a ground system, an armored cable, a remote transmission system and a time domain electromagnetic logging instrument; the remote transmission system is connected with the time domain electromagnetic logging instrument and is arranged in a borehole; the time domain electromagnetic logging instrument comprises an electronic circuit, an acquisition module and a transmission module which are sequentially arranged from top to bottom; the electronic circuit is connected with the acquisition module and the transmission module for detection; the acquisition module comprises a first array type three-component magnetic receiving sensor, a second array type three-component magnetic receiving sensor, an electric receiving sensor, a third array type three-component magnetic receiving sensor and a fourth array type three-component magnetic receiving sensor which are sequentially arranged from top to bottom; and the transmission module comprises a magnetic source and an electric source which are sequentially arranged from top to bottom. The time domain magnetic and electric hybrid transmission source is adopted for transmission, the array type magnetic sensor is adopted for reception and the electric sensor is adopted for reception, so that the source distance of the detector is shortened, and the borehole far detection is realized.

Description

Technical Field

[0001] This invention belongs to the field of petroleum geophysical exploration technology, specifically to a wellbore time-domain electromagnetic remote detection device and method. Background Technology

[0002] Remote wellbore exploration is an innovative logging technology that has developed in recent years. It evolves from near-wellbore measurement to far-wellbore measurement, enabling wellbore surveying, forward sighting, and deep / far-range exploration. It is currently one of the most critical and challenging frontier issues in the logging field. With the deepening of oil exploration and development, the focus has shifted from structural oil and gas reservoirs to complex and concealed reservoirs. The difficulty of oil, natural gas, and mineral exploration is gradually increasing, placing higher demands on geophysical exploration technologies. There is a growing desire to understand reservoir conditions, including geological structures, lateral reservoir distribution, fracture development, and fault distribution, at a greater distance from the wellbore. The seismic resolution scale for complex oil and gas reservoirs cannot accurately depict the geological structures near and between wells, favorable reservoir zones, remaining oil distribution, oil-water interfaces, and target layers lost across faults. Conventional logging, due to its limited depth, struggles to accurately evaluate reservoirs a few meters away from the well. Furthermore, as the exploration and development of unconventional reservoirs becomes increasingly important, the evaluation of the effects of unconventional oil and gas reservoir stimulation, acid fracturing, and other engineering projects is also becoming increasingly prominent. Traditional frequency-domain electromagnetic logging achieves long-distance detection by reducing the frequency and increasing the transmit / receive offset, which leads to an increase in the length and weight of the detector and a limited detection distance. Summary of the Invention

[0003] To address the problems existing in the prior art, this invention provides a time-domain electromagnetic remote detection device and method for wells, which uses a time-domain magnetoelectric hybrid emission source for transmission, and an array-type magnetic source sensor and an electrical sensor for reception, greatly shortening the detector-source distance and realizing remote detection of wells.

[0004] To achieve the above objectives, the present invention provides the following technical solution:

[0005] A wellbore time-domain electromagnetic remote detection device includes a surface system, an armored cable, a remote transmission system, and a time-domain electromagnetic logging instrument;

[0006] The ground system is connected to the remote transmission system via an armored cable. The remote transmission system is connected to a time-domain electromagnetic logging instrument and placed in the wellbore.

[0007] The time-domain electromagnetic logging instrument includes, from top to bottom, an electronic circuit, a data acquisition module, and a transmission module; the electronic circuit connects the data acquisition module and the transmission module for detection.

[0008] The transmitting module includes a magnetic source and an electrical source arranged sequentially from top to bottom.

[0009] Preferably, the electronic circuitry includes a magnetoelectric hybrid emission circuit module, a three-component array acquisition circuit module, and a main control module; the magnetoelectric hybrid emission circuit module is connected to the magnetic source and the electrical source.

[0010] The three-component array acquisition circuit module is interactively connected to the main control module; the main control module is connected to the input terminal of the waveform generator, and the output terminal of the waveform generator is connected to the input terminal of the magnetoelectric hybrid transmission circuit module; the main control module is interactively connected to the communication module.

[0011] Furthermore, the magneto-electric hybrid emission circuit module includes a magnetic emission drive module and an electric emission drive module. The output terminal of the waveform generator is connected to the input terminal of the fast shutdown circuit and the input terminal of the electric emission drive module, respectively. The output terminal of the fast shutdown circuit is connected to the input terminal of the magnetic emission drive module. The electric emission drive module is used to apply pulse excitation to the electrical source; the magnetic emission drive module is used to apply pulse excitation to the magnetic source.

[0012] Furthermore, the three-component array acquisition circuit module includes two electrical signal preprocessing modules and two multi-channel magnetic signal preprocessing modules, all of which are connected to the main control module; the two multi-channel magnetic signal preprocessing modules are used to receive and process magnetic signals; and the two electrical signal preprocessing modules are used to receive and process electrical signals.

[0013] Preferably, the electrical source includes an electric dipole made of a non-polarized electrode.

[0014] Preferably, the electrical source includes a first electrode and a second electrode; the first electrode is disposed on the downhole instrument probe, and the second electrode is disposed on the wellhead surface.

[0015] Preferably, the acquisition module includes a first array-type three-component magnetic receiving sensor, a second array-type three-component magnetic receiving sensor, an electrical receiving sensor, a third array-type three-component magnetic receiving sensor, and a fourth array-type three-component magnetic receiving sensor arranged sequentially from top to bottom.

[0016] Preferably, the remote transmission system is a megabit-level remote transmission system; the armored cable is a seven-core cable.

[0017] A borehole time-domain electromagnetic remote sensing method includes the following processes:

[0018] The ground system sends a command, and the time-domain electromagnetic logging instrument starts working, continuously measuring along the wellbore. The electrical and magnetic sources emit pulse currents, and the acquisition module collects the secondary electromagnetic field.

[0019] The signals acquired by the acquisition module are transmitted to the ground system via the remote transmission system. The ground system preprocesses the signals and maps the secondary induced electromagnetic field signals of the strata.

[0020] The secondary induced electromagnetic field signal is inverted to complete the imaging of the electrical parameters of the wellbore electromagnetic remote detection well.

[0021] Preferably, the magnetoelectric hybrid transmitting circuit module applies pulse excitation to both the magnetic and electrical sources. The signal transmission from the magnetic source is controlled by the main control module to generate a pulse waveform, which is then controlled by the magnetic transmission drive circuit to transmit the multi-turn axial transmitting coil.

[0022] The electrical source emits the same pulse waveform, which is generated by the waveform generator controlled by the main control module and then transmitted under the control of the electrical transmission drive module.

[0023] Compared with the prior art, the present invention has the following beneficial technical effects:

[0024] This invention provides a borehole time-domain electromagnetic remote sensing device that employs a hybrid magnetoelectric source for emission, a three-component magnetic sensor for reception, and an axial electrical sensor for reception. Compared with simple magnetic source emission and magnetic sensor reception, the coupling relationship with the formation is more diverse in terms of mutual coupling and interaction, and the information collected is richer. It can collect not only magnetic field signals but also electric field signals, realizing multi-dimensional and multi-parameter measurement, making it more applicable. Furthermore, the mutual constraints are beneficial for data inversion and electrical profile imaging.

[0025] The measurement principle of this invention is as follows: When the excitation current pulse is suddenly cut off, the change in the primary field induces a current (eddy current) in the formation. This induced current generates a secondary electromagnetic field, which decays over time. The decay curve reflects the distribution of the formation's electrical structure. The time-domain electromagnetic field is a diffuse field, and its propagation mode can be described using the "smoke ring theory." This is the physical principle of long-distance time-domain electromagnetic field detection. The measurement of the wellbore's time-domain electromagnetic field does not require a high source-to-source distance; a shorter instrument length can achieve the long-range well-side detection capabilities previously only achievable with longer frequency-domain instruments. By employing a hybrid excitation system of electrical and magnetic sources, along with an array of three-component magnetic receiver sensors and an axial electrical receiver sensor, long-range and forward-range wellbore electromagnetic measurements are achieved. This can be used in open-hole wireline logging and logging while drilling, demonstrating excellent application results in well-side geological characterization, displacement front identification, and fracturing effect evaluation. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the borehole time-domain electromagnetic measurement system of the present invention;

[0027] Figure 2 This is a schematic diagram of the borehole time-domain electromagnetic logging device of the present invention;

[0028] Figure 3a This is a measurement mode diagram of the wellbore time-domain electromagnetic logging device of the present invention, in which all the electrical sources of the detector are placed in the wellbore.

[0029] Figure 3b This is a measurement mode diagram showing the distribution of the detector's electrical source in the wellbore time-domain electromagnetic logging device of the present invention, with the detector's electrical source located in the wellbore and on the surface.

[0030] Figure 4 This is a schematic diagram of the transmitted pulse waveform of the present invention;

[0031] Figure 5a A schematic diagram of an electromagnetic field excited by a magnetic source;

[0032] Figure 5b A schematic diagram of an electromagnetic field excited by an electrical source;

[0033] Figure 6 This is a schematic diagram of the circuit module of a borehole time-domain electromagnetic logging device.

[0034] Figure 7a The response characteristic curves for axial transmission and axial reception;

[0035] Figure 7b The response characteristic curves for circumferential transmission and circumferential reception;

[0036] Figure 8 This is a flowchart illustrating the workflow of a borehole time-domain electromagnetic remote detection method according to the present invention.

[0037] In the diagram: 11. Ground system; 12. Armored cable; 13. Remote transmission system; 14. Time-domain electromagnetic logging instrument; 21. Electronic circuit; 22. Acquisition module; 23. Transmission module; 31. Electric dipole; 32. Magnetic source; 33. First array three-component magnetic receiving sensor; 34. Second array three-component magnetic receiving sensor; 35. Electrical receiving sensor; 36. Third array three-component magnetic receiving sensor; 37. Fourth array three-component magnetic receiving sensor; 38. First electrode; 39. Second electrode. Detailed Implementation

[0038] The present invention will be further described in detail below with reference to specific embodiments. These descriptions are for explanation purposes only and are not intended to limit the scope of the invention.

[0039] This invention discloses a wellbore time-domain electromagnetic remote detection device, based on transient electromagnetics. This device can break through the spatial evaluation scale of traditional logging techniques, providing a detailed description of the structural morphology, reservoir distribution, oil and gas enrichment zones, and fluid distribution of reservoirs far from the wellbore (up to 50 meters from the wellhead). It can dynamically monitor the sweep front and direction of water-drive, steam-drive, and polymer-drive operations during oilfield development, improving the drilling encounter rate of adjustment wells in rolling exploration and development, optimizing development plans, and increasing ultimate recovery. In terms of detection depth and resolution, this time-domain electromagnetic remote detection technology fills the gaps in the geological evaluation scale of conventional logging and seismic exploration.

[0040] This invention employs the measurement principle of time-domain electromagnetic long-distance detection technology: When the excitation current pulse is suddenly cut off, the change in the primary field induces a current (eddy current) in the formation. This induced current generates a secondary electromagnetic field, which decays over time. Its decay curve reflects the distribution of the formation's electrical structure. The time-domain electromagnetic field is a diffuse field, and its propagation mode can be described using the "smoke ring theory." This is the physical principle of time-domain electromagnetic long-distance detection. The measurement of the wellbore's time-domain electromagnetic field does not require a high source-to-source distance; a shorter instrument length can achieve the long-distance well-side detection capabilities previously only achievable with longer frequency-domain instruments. By using a hybrid excitation system of electric and magnetic dipoles, an array of three-component magnetic receiver sensors, and an axial electrical receiver sensor, the invention achieves both long-distance and forward-looking wellbore electromagnetic measurements. It can be used in open-hole wireline logging and logging while drilling, demonstrating excellent application results in well-side geological characterization, displacement front identification, and fracturing effect evaluation.

[0041] The present invention provides a borehole time-domain electromagnetic remote detection device, which proposes a working mode of hybrid emission from a magnetic source and an electrical source, and reception using a columnar three-component magnetic sensor and an axial electrical sensor.

[0042] like Figure 1 As shown, a wellbore time-domain electromagnetic remote detection device of the present invention includes a surface system 11, an armored cable 12, a remote transmission system 13, and a time-domain electromagnetic logging instrument 14, wherein the time-domain electromagnetic logging instrument consists of two parts: electronic circuitry and a probe, as shown in the figure. Figure 2 As shown, the electronic circuit 21 and the probe part include a transmitting module 23 and a data acquisition module 22.

[0043] like Figure 3a and 3b As shown, the instrument probe includes an electrical source, a magnetic source 32, a first array-type three-component magnetic receiving sensor 33, a second array-type three-component magnetic receiving sensor 34, a third array-type three-component magnetic receiving sensor 36, a fourth array-type three-component magnetic receiving sensor 37, and an electrical receiving sensor 35.

[0044] Loading such as magnetic source 32 and electrical source Figure 4 Pulse waveform, where a magnetic source excites an axial magnetic field in the formation, such as... Figure 5a As shown; an electrical source induces a circumferential magnetic field in the strata, such as... Figure 5b As shown, through coupling with different strata, the array-type three-component magnetic receiving sensor and the axial electric receiving sensor receive secondary electromagnetic induction signals that decay over time.

[0045] The electrical source can emit light in two modes. In the first mode, two emitting electrodes form an electric dipole 31, which is placed on the downhole instrument probe. In the second mode, the first electrode 38 is placed on the downhole instrument probe, and the second electrode 39 is placed near the wellhead on the surface.

[0046] The propagation mode of the electromagnetic field in the borehole time domain is similar to that in the half-space time domain. Over time, the electromagnetic field diffuses further away and gradually weakens. Information acquired by early receiving sensors is related to geological information near the wellbore, while information acquired later is related to information far from the wellbore.

[0047] This invention utilizes the secondary induced electromagnetic field information that decays over time, collected by a receiving sensor, to invert geological parameters such as formation electrical parameters, formation boundaries, and oil-water boundaries at different distances from the wellbore.

[0048] The principle block diagram of the electronic circuit module of the present invention is as follows: Figure 6 As shown, the design mainly consists of a magneto-electric hybrid transmission circuit module, a three-component array acquisition circuit module, and a main control module. The magneto-electric hybrid transmission circuit module applies pulse excitation to both the magnetic and electrical sources. The transmission of the magnetic source signal is first achieved by the main control module controlling a waveform generator to produce a pulse waveform, which is then driven by a drive circuit to control the transmission of the multi-turn axial transmission coil. The electrical source transmits the same pulse waveform, also generated by the main control module controlling a waveform generator, and then controlled by the electrical transmission drive module for transmission.

[0049] The three-component array acquisition circuit module detects three-component time-domain magnetic field signals through receiving coils and receives electric field signals after passing through the formation through electrodes. Since each three-component receiving coil acquires three signals, a multi-channel magnetic signal preprocessing module amplifies and filters the acquired signals. The processed signals are then converted from analog to digital signals by an A / D converter and transmitted to the MCU. Electrical signal acquisition follows a similar process. Multiple MCUs operate simultaneously to achieve real-time acquisition of the array signals and communicate with the main control module via a CAN bus. In addition to controlling the transmission and acquisition functions, the main control module connects to the communication module via a serial interface to enable communication between the downhole instrument and the surface system.

[0050] Figure 7a and Figure 7bThe borehole time-domain electromagnetic response characteristic curves are presented for different formation interface dip angles with the detector distance from the dipped formation interface remaining constant. Figure 7a The response characteristic curves for axial transmission and axial reception are given. Figure 7b The response characteristic curves for circumferential transmission and reception are presented. It can be seen that different excitation modes have different coupling relationships with the formation. Under axial transmission and reception conditions, the signal amplitude increases with increasing dip angle. However, under circumferential transmission and reception conditions, the signal amplitude decreases with increasing dip angle, showing the opposite trend. Utilizing these coupling relationships and differences in response characteristic curves, the electrical and geological parameters of the formation can be mutually constrained and inverted.

[0051] Example

[0052] The basic device structure of the present invention is as follows Figure 1 As shown, its composition is as follows: Surface system 11, which consists of surface acquisition software, surface hardware acquisition system, control system, and cable winch; armored cable 12 is a seven-core cable; remote transmission system 13 is a megabit-level remote transmission system; time-domain electromagnetic logging instrument 14, which consists of electronic circuitry and a probe, as shown... Figure 2 As shown. The electronic circuit 21 has a metal outer shell; the probe part includes a transmitting module 23 and a acquiring module 22, and its outer shell is made of fiberglass.

[0053] Instrument probe section such as Figure 3a and 3b As shown, the electrical source is a non-polarized metal electrode; the magnetic source 32 is an axially wound multi-turn coil.

[0054] The electrical source can emit in two modes. In the first mode, two emitting electrodes form an electric dipole 31, which is placed on the downhole instrument probe and is made of non-polarizable electrode material. In the second mode, the first electrode 38 is placed on the downhole instrument probe, and the second electrode 39 is placed near the wellhead on the surface.

[0055] Loading such as magnetic source 32 and electrical source Figure 4 The pulse waveform shows that the magnetic source 32 excites an axial magnetic field in the formation, while the electric source excites a circumferential magnetic field. As time progresses, the electromagnetic field diffuses further into the wellbore, and its intensity gradually weakens. The emission effect of this invention is comparable to that of a three-component electromagnetic excitation. Through coupling with different formations, a three-dimensional multi-parameter secondary induced electromagnetic field is generated within the formation.

[0056] The first array of three-component magnetic receiving sensors 33, 34, 36, and 37 are three-component multi-turn coils with a common center point and mutually orthogonal in pairs; the electrical receiving sensor 35 consists of two non-polarized metal electrodes. The three-component magnetic receiving sensors receive three-dimensional secondary induced magnetic field signals, and the electrical receiving sensors receive secondary induced electric field signals. The signal acquisition time window is adjustable according to geological and wellbore conditions, ranging from a few micrometers to a few seconds.

[0057] During the logging process, the ground acquisition software controls the logging flow. The software controls the instrument to enter logging mode, and the ground hardware system supplies power to the downhole time-domain electromagnetic instrument 14 through a seven-core cable. The software also controls the time-domain electromagnetic instrument to select different duty cycles according to different geological conditions and well conditions. At the same time, it excites the electric and magnetic sources to work, and continuously collects the secondary magnetic field and electric field signals induced by the formation along the well by magnetic and electric sensors. The signals are converted into digital signals by A / D conversion and uploaded to the ground acquisition system through a remote transmission system. The acquisition software then uses a preprocessing workflow to generate a three-dimensional map of the secondary magnetic field and electric field.

[0058] Specific circuit operation mode: The principle block diagram of the electronic circuit module of this invention is as follows: Figure 6 As shown, the design mainly consists of a magneto-electric hybrid transmission circuit module, a three-component array acquisition circuit module, and a main control module. The magneto-electric hybrid transmission circuit module applies pulse excitation to both the magnetic and electrical sources. The transmission of the magnetic source signal is first achieved by the main control module controlling a waveform generator to produce a pulse waveform, which is then driven by a drive circuit to control the transmission of the multi-turn axial transmission coil. The electrical source transmits the same pulse waveform, also generated by the main control module controlling a waveform generator, and then controlled by the electrical transmission drive module for transmission.

[0059] The three-component array acquisition circuit module detects three-component time-domain magnetic field signals through acquisition coils and acquires electric field signals after passing through the strata through electrodes. Each depth acquisition point corresponds to 12 magnetic field signals, 2 electric field signals, and one potential difference signal. Since the source distance of each transmitter and receiver is different, it forms a single transmission and multiple array receptions, realizing multi-dimensional, multi-parameter, multi-source distance full-domain measurement.

[0060] Since each three-component receiving coil acquires three signals, a multi-channel magnetic signal preprocessing module is used to amplify and filter the acquired signals. The processed signals are then converted from analog to digital signals by an A / D converter and transmitted to the MCU. The acquisition of electrical signals is similar. Through calculation, a potential difference signal can also be obtained from the electric field signal.

[0061] Multiple MCUs operate simultaneously to achieve real-time acquisition of array signals and communicate with the main control module via a CAN bus. In addition to controlling transmission and acquisition functions, the main control module also connects to the communication module via a serial interface to enable communication between downhole instruments and the surface system.

[0062] Downhole signals are transmitted to the surface acquisition system, where the acquisition software preprocesses and maps the data. Simultaneously, rapid inversion software and geological interpretation software can be integrated into the acquisition software system to enable rapid on-site geological and engineering applications.

[0063] The propagation mode of the electromagnetic field in the borehole time domain is similar to that in the half-space time domain. Over time, the electromagnetic field diffuses further away and gradually weakens. Information acquired by early-stage sensors is related to geological information near the wellbore, while information acquired later is related to information further away from the wellbore. Its diffusion depth is:

[0064]

[0065] Where: δ TD Let μ0 be the time-domain electromagnetic field diffusion depth, μ0 be the permeability of air, σ be the conductivity of the uniform stratum, and t be the electromagnetic field diffusion time.

[0066] By utilizing time-varying secondary induced electromagnetic field information acquired by receiving sensors, geological parameters such as formation electrical parameters, formation boundaries, and oil-water boundaries at different distances from the wellbore are retrieved. The relationship between the induced voltage of the magnetic source and formation resistivity, and the propagation time, is as follows:

[0067]

[0068] Where V is the induced voltage, ρ is the formation resistivity, and t is the propagation time. The electrical source can be derived using the electromagnetic reciprocity principle.

[0069] The operating mode of time-domain electromagnetic logging instruments, the excitation of the transmitting circuit is as follows: Figure 4 The pulse signal is emitted by the electrical source module and the magnetic source module. The circumferential magnetic field excited by the electrical source and the axial magnetic field excited by the magnetic source gradually diffuse away from the wellbore in the formation over time. The three-part magnetic sensor and electrical sensor receive the secondary electromagnetic field generated by the electrical source and the magnetic source in the formation. This electromagnetic field signal decays over time and is related to formation parameters such as the electrical conductivity of the formation, the formation interface, and the oil-water interface. Through data processing, electrical parameter inversion and other workflows, the electrical parameter profile and geological parameter profile around the wellbore can be inverted, thereby realizing the electromagnetic remote detection imaging of the wellbore.

[0070] like Figure 8 As shown, a borehole time-domain electromagnetic remote sensing method of the present invention includes the following processes:

[0071] The ground system 11 sends a command, and the time-domain electromagnetic logging instrument 14 starts working, continuously measuring along the wellbore. The electrical source and magnetic source 32 emit pulse currents, and the acquisition module 22 acquires the secondary electromagnetic field.

[0072] The signals acquired by the acquisition module 22 are transmitted to the ground system 11 through the remote transmission system 13. The ground system preprocesses the signals and maps the secondary induced electromagnetic field signals of the strata.

[0073] The secondary induced electromagnetic field signal is inverted to realize the calculation of electrical parameters and imaging.

[0074] Geological interpretation of electrical parameters enables formation interface identification, oil-water interface identification, geological parameter calculation, and completion of borehole electromagnetic remote detection imaging.

Claims

1. A borehole time-domain electromagnetic remote detection device, characterized in that, It includes a surface system (11), armored cable (12), remote transmission system (13) and time-domain electromagnetic logging instrument (14). The ground system (11) is connected to the remote transmission system (13) via an armored cable (12). The remote transmission system (13) is connected to the time-domain electromagnetic logging instrument (14) and placed in the wellbore. The time-domain electromagnetic logging instrument (14) includes an electronic circuit (21), a data acquisition module (22), and a transmission module (23) arranged sequentially from top to bottom; the electronic circuit (21) connects the data acquisition module (22) and the transmission module (23) for detection; The transmitting module (23) includes a magnetic source (32) and an electrical source arranged sequentially from top to bottom. The magnetic source (32) generates an axial magnetic field in the stratum, and the electrical source generates a circumferential magnetic field in the stratum. The electronic circuit (21) includes a magnetoelectric hybrid emission circuit module, a three-component array acquisition circuit module, and a main control module; the magnetoelectric hybrid emission circuit module is connected to the magnetic source (32) and the electrical source; The three-component array acquisition circuit module is interactively connected to the main control module; the main control module is connected to the input terminal of the waveform generator, and the output terminal of the waveform generator is connected to the input terminal of the magnetoelectric hybrid transmission circuit module; the main control module is interactively connected to the communication module. The magneto-electric hybrid emission circuit module includes a magnetic emission drive module and an electric emission drive module. The output terminal of the waveform generator is connected to the input terminal of the fast shutdown circuit and the input terminal of the electric emission drive module, respectively. The output terminal of the fast shutdown circuit is connected to the input terminal of the magnetic emission drive module. The electric emission drive module is used to apply pulse excitation to the electrical source. The magnetic emission drive module is used to apply pulse excitation to the magnetic source (32); The three-component array acquisition circuit module includes two electrical signal preprocessing modules and two multi-channel magnetic signal preprocessing modules, all of which are connected to the main control module. Two multi-channel magnetic signal preprocessing modules are used to receive and process magnetic signals; the two-channel electrical signal preprocessing modules are used to receive and process electrical signals.

2. The borehole time-domain electromagnetic remote detection device according to claim 1, characterized in that, The electrical source includes an electric dipole (31) made of a non-polarized electrode.

3. The wellbore time-domain electromagnetic remote detection device according to claim 1, characterized in that, The electrical source includes a first electrode (38) and a second electrode (39); the first electrode (38) is disposed on the downhole instrument probe, and the second electrode (39) is disposed on the wellhead surface.

4. The borehole time-domain electromagnetic remote detection device according to claim 1, characterized in that, The acquisition module (22) includes a first array-type three-component magnetic receiving sensor (33), a second array-type three-component magnetic receiving sensor (34), an electrical receiving sensor (35), a third array-type three-component magnetic receiving sensor (36), and a fourth array-type three-component magnetic receiving sensor (37), arranged sequentially from top to bottom.

5. A borehole time-domain electromagnetic remote detection device according to claim 1, characterized in that, The remote transmission system (13) is a megabit-level remote transmission system; the armored cable (12) is a seven-core cable.

6. A borehole time-domain electromagnetic remote detection method, characterized in that, A wellbore time-domain electromagnetic remote detection device according to any one of claims 1-5 includes the following process. The ground system (11) sends a command, and the time-domain electromagnetic logging instrument (14) starts working, continuously measuring along the wellbore. The electrical source and magnetic source (32) emit pulse currents, and the acquisition module (22) acquires the secondary electromagnetic field. The signal collected by the acquisition module (22) is sent to the ground system (11) through the remote transmission system (13). The ground system preprocesses the signal and maps the secondary induced electromagnetic field signal of the stratum. The secondary induced electromagnetic field signal is inverted to complete the imaging of the electrical parameters of the wellbore electromagnetic remote detection well.

7. The borehole time-domain electromagnetic remote detection method according to claim 6, characterized in that, The magnetoelectric hybrid emission circuit module applies pulse excitation to the magnetic source (32) and the electrical source. The signal emission of the magnetic source (32) is controlled by the main control module to generate a pulse waveform through the waveform generator, and the emission control of the multi-turn axial emission coil is achieved through the magnetic emission drive circuit. The electrical source emits the same pulse waveform, which is generated by the waveform generator controlled by the main control module and then transmitted under the control of the electrical transmission drive module.

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