A nuclear magnetic resonance logging electronic circuit function simulation test device

Abstract

The present invention provides a functional simulation test device for nuclear magnetic resonance (NMR) logging electronic circuits. This device can replace the probe of an NMR logging instrument to perform reliability testing of electronic circuit sections. Compared with physical logging instrument probes, this device has smaller size, adjustable parameters, and adjustable test modes. It can simulate downhole NMR probe parameters to enable real-time reliability testing of electronic circuits. The device has four test functions, including single excitation testing, active excitation acquisition testing, controlled source excitation acquisition testing, and simulated probe testing. The device can interface with any NMR logging system to perform functional testing of the NMR system's electronic circuits.

Description

Technical Field

[0001] The present invention relates to the technical field of nuclear magnetic resonance well logging, and in particular to a nuclear magnetic resonance well logging electronic circuit function simulation test device. Background Art

[0002] The nuclear magnetic resonance logging tool uses the principle of nuclear magnetic resonance to measure the formation conditions around the oil well, thereby detecting information related to oil and gas characteristics in the formation. It mainly uses the probe to form a magnetic field and collect resonance signals, and then analyzes the fluids in the pores of the formation rock based on the resonance signals to directly measure the density of hydrogen nuclei in the reservoir fluid. The nuclear magnetic data obtained using the nuclear magnetic resonance signal can be directly converted into apparent water porosity, and the existence, content and related characteristics of different fluids in the reservoir can be determined.

[0003] NMR instruments have evolved in response to the development of NMR methods and their diverse application contexts. The system components of NMR instruments can be functionally divided into sensors, electronic circuits, and host computer software. The sensor consists of a magnet and an antenna. The magnet generates a static magnetic field B0 to polarize the protons in the sample. The antenna is used to generate an alternating electromagnetic field B1 perpendicular to the static magnetic field (referred to as an RF magnetic field because the operating frequency falls within the RF range), generating NMR and receiving NMR signals. Electronic circuits are the foundation of NMR measurements, primarily responsible for communication with the ground system, generating pulse sequence timing, generating instrument control commands, exciting the antenna to transmit RF pulses, and amplifying and collecting echo signals.

[0004] The NMR logging electronic circuit functional simulation test device, with its compact size, adjustable parameters, and adjustable test modes, can simulate downhole NMR probe parameters to enable real-time reliability testing of electronic circuits. This device is of great engineering significance for the research and development of NMR logging instrument electronic circuits, providing a valuable reference for the optimized design of industrialized NMR logging instrument electronic circuits. It also tests the performance of cables and while-drilling NMR logging instruments, providing an experimental platform for verifying and optimizing the overall performance of electronic circuit subs.

[0005] However, during the development and testing of existing nuclear magnetic logging instrument electronic circuits, there is a problem that electronic circuit system testing and functional testing cannot be performed due to the lack of available probe loads, the inconvenience of probe movement, and the difficulty in changing probe parameters. Summary of the Invention

[0006] In order to overcome the above technical problems, the present invention proposes a nuclear magnetic resonance logging electronic circuit function simulation test device, which can not only serve as the output load of the electronic circuit part, but also conveniently realize the data acquisition test and the test functions of different instrument parameters and sample components.

[0007] The technical solution of the present invention is: a nuclear magnetic resonance logging electronic circuit function simulation test device, comprising: a nuclear magnetic resonance simulation function module, a fixed value tuning circuit, an antenna interface module, a signal generation module and a controllable mode interface;

[0008] The antenna interface module is used to connect to the electronic circuit of the nuclear magnetic resonance logging instrument. The nuclear magnetic resonance excitation signal is emitted from the electronic circuit of the nuclear magnetic resonance logging instrument, connected to the antenna interface module through a twisted shielded pair cable or an aviation pin, and then enters the resonant circuit composed of the fixed value tuning circuit and the nuclear magnetic resonance simulation function module after noise suppression through the antenna interface module.

[0009] The nuclear magnetic resonance simulation function module can output an analog acquisition signal. The signal returns along the original transmission excitation path, first passes through the fixed value tuning circuit, then enters the antenna interface module, and returns to the electronic circuit of the nuclear magnetic resonance logging instrument to complete the signal acquisition function;

[0010] One end of the signal generating module is connected to the nuclear magnetic resonance simulation function module, and the other end is connected to the controllable mode interface. The controllable mode interface is connected to the electronic circuit of the nuclear magnetic resonance logging instrument and is used to receive mode control commands and adjust the working mode of the signal generating module.

[0011] Furthermore, the device parameters and test modes are adjustable, and the function test and reliability test of the electronic circuit can be realized by selecting the test mode to simulate the parameters of the downhole nuclear magnetic resonance probe.

[0012] Furthermore, it includes: being able to realize high-voltage radio frequency excitation load and simultaneously giving corresponding test signals according to different modes, wherein the high voltage is 1000-5000V.

[0013] Furthermore, the fixed-value tuning circuit can match the load parameters in the nuclear magnetic resonance simulation function module to achieve the resonance function of the radio frequency signal.

[0014] Furthermore, the antenna interface module is used to interface with the electronic circuit of the nuclear magnetic resonance logging instrument.

[0015] Furthermore, the signal generation module can generate analog radio frequency signals to provide signal support for the acquisition function test of the nuclear magnetic resonance logging instrument.

[0016] Furthermore, the controllable mode interface is used to convert the control signal from the electronic circuit of the nuclear magnetic resonance logging instrument into a command mode signal. At the same time, the module has a mode selection switch function for selecting different test modes.

[0017] Furthermore, the different test modes include single excitation test, active excitation acquisition test, controllable source excitation acquisition test and analog probe test mode, and the different test modes can be selected by program control and switch control.

[0018] Furthermore, a separate excitation test provides a load parameter state that does not generate nuclear magnetic resonance when testing the emission function of the electronic circuit of the nuclear magnetic resonance logging instrument;

[0019] Active excitation acquisition test is to provide load capacity and give fixed analog signal for electronic circuit acquisition test when testing the electronic circuit system function of nuclear magnetic resonance logging instrument;

[0020] Controllable source excitation acquisition test: When testing the electronic circuit system of nuclear magnetic resonance logging instruments, it can not only provide load capacity but also provide simulated echo signals according to control commands for electronic circuit acquisition testing;

[0021] The analog probe test mode is to provide a load parameter state and generate nuclear magnetic resonance phenomenon when the electronic circuit of the nuclear magnetic resonance logging instrument is testing the system function.

[0022] The present invention provides a functional simulation test device for nuclear magnetic resonance (NMR) logging electronic circuits. This device can replace the probe of an NMR logging instrument to perform reliability testing of electronic circuit sections. Compared with physical logging instrument probes, this device has smaller size, adjustable parameters, and adjustable test modes. It can simulate downhole NMR probe parameters to enable real-time reliability testing of electronic circuits. The device has four test functions, including single excitation testing, active excitation acquisition testing, controlled source excitation acquisition testing, and simulated probe testing. The device can interface with any NMR logging system to perform functional testing of the NMR system's electronic circuits.

[0023] Beneficial effects:

[0024] The beneficial effects of the present invention are that the mode load used for electronic circuit testing can be realized, and the device is small in size and easy to carry, and can also meet the needs of circuit function testing of various instruments. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The present invention will be further described below with reference to the accompanying drawings and examples.

[0026] FIG1( a ) is a block diagram of the design structure principle of the present invention;

[0027] FIG1( b ) is a block diagram of the device of the present invention;

[0028] Figure 2 It is an embodiment of a nuclear magnetic resonance logging electronic circuit function simulation test device;

[0029] Figure 3 It is a schematic diagram of a fixed value tuning circuit.

[0030] In the figure, 1. Nuclear magnetic resonance simulation function module, 2. Fixed value tuning circuit, 3. Antenna interface module, 4. Signal generation module, 5. Controllable mode interface, 6. Static magnetic field magnet, 7. Test sample, 8. Radio frequency coil, 9. Signal antenna, 10. Nuclear magnetic resonance logging instrument electronic circuit. DETAILED DESCRIPTION

[0031] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] In FIG1 , the test device of the present invention includes: an antenna interface module 3, a fixed value tuning circuit 2, a nuclear magnetic resonance simulation function module 1, a signal generation module 4, and a controllable mode interface 5; wherein,

[0033] The electronic circuit 10 of the nuclear magnetic resonance logging instrument is connected to the antenna interface module 3. The nuclear magnetic resonance excitation signal is emitted from the electronic circuit 10 of the nuclear magnetic resonance logging instrument and connected to the antenna interface module 3 through a twisted shielded pair cable or an aviation pin. After noise suppression by the antenna interface module 3, it enters the resonant circuit composed of the fixed value tuning circuit 2 and the nuclear magnetic resonance simulation function module 1. The nuclear magnetic resonance simulation function module 1 can output a sinusoidal signal generated by the simulated sample in mode two and mode three. The signal returns along the original transmission excitation path, first passes through the fixed value tuning circuit 2, then enters the antenna interface module 3, and returns to the electronic circuit 10 of the nuclear magnetic resonance logging instrument to complete the signal acquisition function.

[0034] The device has four test functions selected by the control, including:

[0035] Mode 1: Single excitation test: When testing the emission function of the electronic circuit of the nuclear magnetic resonance logging instrument, a load parameter state is provided without generating nuclear magnetic resonance phenomenon;

[0036] In this mode, the controllable mode interface 5 and the signal generating module 4 do not work, and the resonant load composed of the nuclear magnetic resonance simulation function module 1 and the fixed value tuning circuit 2 realizes the load function required for the nuclear magnetic resonance instrument to test the transmission signal alone.

[0037] Mode 2: Active excitation acquisition test: When testing the electronic circuit system function of the nuclear magnetic resonance logging instrument, it can provide load capacity and give a fixed analog signal for electronic circuit acquisition test;

[0038] In this mode, the system can not only realize the functions of mode 1, but also the signal generating module 4 can emit a continuous sinusoidal signal under the mode selection control of the controllable mode interface 5 to test the acquisition function of the nuclear magnetic resonance instrument.

[0039] Mode 3: Controllable source excitation acquisition test; when testing the electronic circuit system function of the nuclear magnetic resonance logging instrument, it can not only provide load capacity but also provide simulated echo signals according to control commands for electronic circuit acquisition testing;

[0040] This mode has the same function as the second mode, but the signal generating module 4 can generate a pseudo echo signal that matches the timing of the transmit pulse sequence under the mode selection control of the controllable mode interface 5 .

[0041] Mode 4: Simulated Probe Test Mode. This mode provides a load parameter state and produces a realistic NMR phenomenon when testing the NMR logging instrument's electronic circuitry. In Figure 1, signal generation module 4 can generate analog signals in Modes 2 and 3 for instrument electronic circuitry acquisition testing. Signal generation module 4 receives control signals from controllable mode interface 5 to select the excitation mode. The controllable mode interface 5 receives signals from two sources: control commands from the NMR logging instrument's electronic circuitry 10 and a selector switch within the controllable mode interface 5 itself, which selects different test modes based on the test objectives.

[0042] exist Figure 2 In the figure, an implementation example of the nuclear magnetic resonance simulation function module 1 is provided, which includes a static magnetic field magnet 6, a radio frequency coil 8, a test sample 7, and a signal antenna 9. The static magnetic field magnet 6 is used to generate a uniform magnetic field, and the magnetic field strength and distribution can be achieved by changing the magnet structure. The radio frequency coil 8 is used to realize the excitation emission simulation load function, and can also be used as a radio frequency signal excitation unit to realize the nuclear magnetic resonance phenomenon with the static magnetic field magnet 6. On the one hand, it can excite the nuclear magnetic signal generated by the sample in the test sample 7, and on the other hand, it can receive the analog signal emitted by the signal antenna 9.

[0043] According to an embodiment of the present invention, the adjustable parameters mainly include two parts:

[0044] 1. The static magnetic field parameters are adjustable. By adjusting and replacing the static magnetic field magnet 6, the intensity and properties of the magnetic field (static magnetic field and gradient magnetic field) can be changed, thereby changing the lamer frequency of nuclear magnetic resonance;

[0045] 2. The test signal is controllable. In one case, the test signal can be directly measured by exciting the nuclear magnetic resonance signal generated by the test sample 7. In the second case, the test function is indirectly realized by generating an analog signal through the controllable mode interface 5, the signal generating module 4 and the signal antenna 9. The parameters such as the test signal frequency, amplitude and phase are adjustable.

[0046] The fixed value tuning circuit 2 is as follows Figure 3 The structure shown, with Figure 2 The combination of the medium radio frequency coil 8 can realize three types of resonant loads suitable for series-parallel structures.

[0047] Although the above describes the illustrative specific embodiments of the present invention to facilitate understanding of the present invention by those skilled in the art, and it should be clear that the present invention is not limited to the scope of the specific embodiments, it is obvious to those skilled in the art that as long as various changes are within the spirit and scope of the present invention as defined and determined by the appended claims, these changes are obvious, and all inventions and creations utilizing the concepts of the present invention are protected.

Claims

1. A nuclear magnetic resonance logging electronic circuit function simulation test device, characterized in that: include: Nuclear magnetic resonance simulation function module, fixed value tuning circuit, antenna interface module, signal generation module and controllable mode interface; The antenna interface module is used to connect to the electronic circuit of the nuclear magnetic resonance logging instrument. The nuclear magnetic resonance excitation signal is emitted from the electronic circuit of the nuclear magnetic resonance logging instrument, connected to the antenna interface module through a twisted shielded pair cable or an aviation pin, and then enters the resonant circuit composed of the fixed value tuning circuit and the nuclear magnetic resonance simulation function module after noise suppression through the antenna interface module. The nuclear magnetic resonance simulation function module can output an analog acquisition signal. The signal returns along the original transmission excitation path, first passes through the fixed value tuning circuit, then enters the antenna interface module, and returns to the electronic circuit of the nuclear magnetic resonance logging instrument to complete the signal acquisition function; One end of the signal generation module is connected to the nuclear magnetic resonance simulation function module, and the other end is connected to the controllable mode interface. The controllable mode interface is connected to the electronic circuit of the nuclear magnetic resonance logging instrument and is used to receive mode control commands and adjust the working mode of the signal generation module; The device parameters and test modes are adjustable, and the function test and reliability test of the electronic circuit can be realized by selecting the test mode to simulate the parameters of the downhole nuclear magnetic resonance probe; Controllable mode interface, used to convert the control signal from the electronic circuit of the nuclear magnetic resonance logging instrument into a command mode signal, and also has a mode selection switch function for selecting different test modes; The different test modes include single excitation test, active excitation acquisition test, controllable source excitation acquisition test and analog probe test mode. Different test modes can be selected by program control and switch control. Single excitation test: when testing the emission function of the electronic circuit of the nuclear magnetic resonance logging instrument, it provides a load parameter state without generating nuclear magnetic resonance phenomenon; Active excitation acquisition test is to provide load capacity and give fixed analog signal for electronic circuit acquisition test when testing the electronic circuit system function of nuclear magnetic resonance logging instrument; Controllable source excitation acquisition test: When testing the electronic circuit system of nuclear magnetic resonance logging instruments, it can not only provide load capacity but also provide simulated echo signals according to control commands for electronic circuit acquisition testing; The analog probe test mode is to provide a load parameter state and generate nuclear magnetic resonance phenomenon when the electronic circuit of the nuclear magnetic resonance logging instrument is testing the system function.

2. The nuclear magnetic resonance logging electronic circuit function simulation test device according to claim 1, characterized in that: include: It can realize high-voltage radio frequency excitation load and give corresponding test signals according to different modes. The high voltage is 1000~5000V.

3. The nuclear magnetic resonance logging electronic circuit function simulation test device according to claim 1, characterized in that: The fixed value tuning circuit can match the load parameters in the nuclear magnetic resonance simulation function module to achieve the resonance function of the radio frequency signal.

4. The nuclear magnetic resonance logging electronic circuit function simulation test device according to claim 1, characterized in that: The signal generation module can generate analog radio frequency signals to provide signal support for the acquisition function test of nuclear magnetic resonance logging instruments.

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