Apparatus and method for locating microfractures in deep salt caverns

Abstract

This application belongs to the field of underground exploration engineering technology, specifically proposing a device and method for locating microfractures in deep salt caverns. The device includes: a surface excitation module, installed on the surface, for applying low-frequency micro-pressure fluctuation signals to the interior of the deep salt cavern and recording the phase timestamps corresponding to the low-frequency micro-pressure fluctuation signals; a downhole detection module, connected to the surface excitation module via a cable and suspended inside the deep salt cavern by the cable, for detecting high-frequency acoustic signals generated when gas leaks from the microfractures in the deep salt cavern and transmitting the high-frequency acoustic signals to a surface computing module; and a surface computing module, installed on the surface and communicatively connected to the surface excitation module and the downhole detection module, for performing phase-locked amplification processing on the high-frequency acoustic signals to locate the microfractures in the deep salt cavern. The technical solution provided by this application can improve the accuracy of locating microfractures in deep salt caverns.

Description

Technical Field

[0001] This application belongs to the field of underground exploration engineering technology, and in particular relates to a device and method for locating micro-fractures in deep salt caverns. Background Technology

[0002] With the large-scale application of underground salt cavern energy storage technology, deep salt cavern gas storage facilities, thanks to the extremely low permeability of salt rock and its excellent self-healing properties of plastic damage, have become core infrastructure for high-pressure natural gas and hydrogen storage, playing a crucial role in ensuring national energy security and supporting peak shaving and valley filling of the power grid. However, under the construction of the cavity, long-term alternating loads from injection and extraction, and geological stress disturbances, the cavity walls of salt caverns are prone to micro-cracks, leading to micro-leakage of high-pressure gas. Existing detection technologies are easily affected by environmental interference such as underground temperature and pressure fluctuations and plastic creep of salt rock, making it impossible to accurately extract leakage signals and achieve spatial location of cracks. This significantly reduces the accuracy of locating micro-cracks in deep salt caverns, making it difficult to promptly identify safety hazards and posing a potential threat to the long-term safe and stable operation of salt cavern gas storage facilities. Therefore, how to improve the accuracy of locating micro-cracks in deep salt caverns has become an urgent technical problem to be solved. Summary of the Invention

[0003] The embodiments of this application provide a device, method, program product, readable storage medium, and electronic device for locating microfractures in deep salt caverns, thereby improving the accuracy of locating microfractures in deep salt caverns.

[0004] Other features and advantages of this application will become apparent from the following detailed description, or may be learned in part from practice of this application.

[0005] According to a first aspect of the embodiments of this application, a device for locating microfractures in deep salt caverns is provided, characterized in that the device comprises: a ground excitation module disposed on the ground surface, used to apply a low-frequency micro-pressure fluctuation signal to the interior of the deep salt cavern and record the phase timestamp corresponding to the low-frequency micro-pressure fluctuation signal; a downhole detection module connected to the ground excitation module via a cable and suspended inside the deep salt cavern via the cable, used to detect high-frequency acoustic signals generated when gas leaks from the microfractures in the deep salt cavern and transmit the high-frequency acoustic signals to the ground computing module; and a ground computing module disposed on the ground surface and communicatively connected to the ground excitation module and the downhole detection module, used to perform phase-locked amplification processing on the high-frequency acoustic signals to locate the microfractures in the deep salt cavern.

[0006] In some embodiments of this application, based on the aforementioned scheme, the ground excitation module includes: a servo fine-tuning pressure valve group for outputting a low-frequency micro-pressure fluctuation signal; a pressure waveform generator for adjusting the fluctuation frequency range and fluctuation amplitude range of the low-frequency micro-pressure fluctuation signal; and a synchronization clock for recording the phase timestamp of the low-frequency micro-pressure fluctuation signal.

[0007] In some embodiments of this application, based on the foregoing scheme, the downhole detection module includes a spherical phased array listening device, a signal processor, and a pressure-bearing sealed chamber. The spherical phased array listening device is disposed inside the pressure-bearing sealed chamber and is used to receive high-frequency acoustic signals generated by micro-cracks in the deep salt cavern, and transmit the high-frequency acoustic signals to the signal processor. The signal processor is used to preprocess the high-frequency acoustic signals and transmit the preprocessed high-frequency acoustic signals to the surface computing module. The pressure-bearing sealed chamber is used to withstand the high-temperature and high-pressure environment within the deep salt cavern, protecting the signal processor and the spherical phased array listening device.

[0008] In some embodiments of this application, based on the aforementioned scheme, the ground computing module includes: an envelope detector for performing Hilbert transform processing on the high-frequency acoustic signal to obtain envelope signals in multiple frequency ranges; a lock-in amplifier for performing lock-in amplification processing on the envelope signals to obtain leakage acoustic signals; and a positioning device for locating microcracks in the deep salt cavern.

[0009] According to a second aspect of the embodiments of this application, a method for locating microfractures in deep salt caverns is provided, characterized in that the method is applied to the apparatus described in any of the first aspects above, the method comprising: applying a low-frequency micro-pressure fluctuation signal to the interior of the deep salt cavern through a ground excitation module, and recording the phase timestamp corresponding to the low-frequency micro-pressure fluctuation signal; receiving a high-frequency acoustic wave signal generated by the microfractures in the deep salt cavern through a downhole detection module, and transmitting the high-frequency acoustic wave signal to a ground computing module; and locating the microfractures in the deep salt cavern by performing phase-locked amplification processing on the high-frequency acoustic wave signal through the ground computing module based on the phase timestamp.

[0010] In some embodiments of this application, based on the aforementioned scheme, the step of applying a low-frequency micro-pressure fluctuation signal to the interior of the deep salt cave via a ground excitation module and recording the phase timestamp corresponding to the low-frequency micro-pressure fluctuation signal includes: generating a preset control signal via a pressure waveform generator and transmitting the preset control signal to a servo micro-pressure adjustment valve group; controlling the servo micro-pressure adjustment valve group based on the preset control signal to apply a low-frequency micro-pressure fluctuation signal of preset frequency and preset amplitude to the interior of the deep salt cave; and recording the phase timestamp of the low-frequency micro-pressure fluctuation signal via a synchronization clock.

[0011] In some embodiments of this application, based on the foregoing scheme, receiving the high-frequency acoustic signal generated by the micro-fractures in the deep salt cavern through the downhole detection module includes: receiving the composite acoustic signal in the deep salt cavern through a spherical phased array listening device; filtering out noise below a preset frequency threshold through a signal processor to obtain a high-frequency signal; and amplifying the high-frequency signal through the signal processor to obtain a high-frequency acoustic signal.

[0012] In some embodiments of this application, based on the aforementioned scheme, the step of locating the microcracks in the deep salt cave by performing phase-locked amplification processing on the high-frequency acoustic signal using a ground computing module based on the phase timestamp includes: performing Hilbert transform processing on the high-frequency acoustic signal using an envelope detector to obtain envelope signals of multiple frequency ranges; performing phase-locked amplification processing on the envelope signals of each frequency range based on the phase timestamp to obtain multiple leakage acoustic signals; and determining the location of the microcracks corresponding to each leakage acoustic signal in the deep salt cave using a positioning device.

[0013] In some embodiments of this application, based on the aforementioned scheme, the step of performing phase-locked amplification processing on the envelope signals of each frequency range to obtain multiple leakage acoustic wave signals includes: mixing the envelope signals of each frequency range with the phase timestamp to obtain a mixed signal; and removing random errors in the mixed signal by digital low-pass filtering to obtain multiple leakage acoustic wave signals.

[0014] In some embodiments of this application, based on the aforementioned scheme, determining the location of the microcracks corresponding to each leakage acoustic signal in the deep salt cavern using a positioning device includes: obtaining the time difference between the times when each listening probe in the spherical phased array listening device receives the leakage acoustic signal, and obtaining the phase difference when each listening probe receives the leakage acoustic signal; and calculating the location of the microcracks corresponding to the leakage acoustic signal in the deep salt cavern using a phased array beamforming synthetic aperture algorithm based on the time difference and the phase difference.

[0015] According to a third aspect of the embodiments of this application, a computer program product is provided, the computer program product including computer instructions stored in a computer-readable storage medium and adapted to be read and executed by a processor to cause a computer device having the processor to perform an operation as described in any of the embodiments of the second aspect above.

[0016] According to a fourth aspect of the embodiments of this application, a computer-readable storage medium is provided, the computer-readable storage medium storing at least one computer program instruction, the at least one computer program instruction being loaded and executed by a processor to perform the operation performed by the method described in any one of the embodiments of the second aspect above.

[0017] According to a fifth aspect of the present application, an electronic device is provided, the electronic device including one or more processors and one or more memories, the one or more memories storing at least one computer program instruction, the at least one computer program instruction being loaded and executed by the one or more processors to perform the operation performed by the method as described in any of the embodiments of the second aspect above.

[0018] Based on the technical solution proposed in this application, the servo micro-adjustment valve group can stably output a safe and damage-free low-frequency micro-pressure fluctuation signal. The pressure waveform generator can accurately adjust the frequency and amplitude parameters of the signal according to the actual working conditions. The synchronization clock can record accurate phase timestamps to provide a reliable reference for subsequent signal processing. This combination of components allows the ground excitation module to stably output a parameter-controllable excitation signal and provide an accurate reference benchmark, thereby effectively avoiding detection errors caused by unstable signal parameters or reference benchmark deviations, and improving the accuracy of locating micro-cracks in deep salt caverns.

[0019] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0020] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort. In the drawings: Figure 1 A schematic diagram of a positioning device for deep salt cave microcracks in one embodiment of this application is shown; Figure 2 A flowchart illustrating a method for locating microcracks in deep salt caves according to one embodiment of this application is shown; Figure 3 A schematic diagram of the structure of an electronic device according to one embodiment of this application is shown. Detailed Implementation

[0021] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0022] Furthermore, the described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. Numerous specific details are provided in the following description to give a thorough understanding of embodiments of this application. However, those skilled in the art will recognize that the technical solutions of this application can be practiced without one or more of the specific details, or other methods, components, apparatuses, steps, etc., can be employed. In other instances, well-known methods, apparatuses, implementations, or operations are not shown or described in detail to avoid obscuring various aspects of this application.

[0023] The block diagrams shown in the accompanying drawings are merely functional entities and do not necessarily correspond to physically independent entities. That is, these functional entities can be implemented in software, in one or more hardware modules or integrated circuits, or in different network and / or processor devices and / or microcontroller devices.

[0024] The flowcharts shown in the accompanying drawings are merely illustrative and do not necessarily include all content and operations / steps, nor do they necessarily have to be performed in the described order. For example, some operations / steps can be broken down, while others can be combined or partially combined; therefore, the actual execution order may change depending on the specific circumstances.

[0025] It should also be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such uses of these terms can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described.

[0026] With the large-scale application of underground salt cavern energy storage technology, deep salt cavern gas storage facilities, thanks to the extremely low permeability of salt rock and its excellent self-healing properties of plastic damage, have become core infrastructure for high-pressure natural gas and hydrogen storage, playing a crucial role in ensuring national energy security and supporting peak shaving and valley filling of the power grid. However, under the construction of the cavity, long-term alternating loads from injection and extraction, and geological stress disturbances, the cavity wall of the salt cavern is prone to micro-cracks, leading to micro-leakage of high-pressure gas. Existing detection technologies are easily affected by environmental interference such as underground temperature and pressure fluctuations and plastic creep of salt rock, making it impossible to accurately extract leakage signals and achieve spatial location of cracks. This significantly reduces the accuracy of locating micro-cracks in deep salt caverns, making it difficult to promptly identify safety hazards and posing a potential threat to the long-term safe and stable operation of salt cavern gas storage facilities. Based on this, this application proposes a device and method for locating micro-cracks in deep salt caverns to improve the accuracy of locating micro-cracks in deep salt caverns.

[0027] Next, we will combine Figure 1 The application provides a detailed description of the device for locating microcracks in deep salt caves.

[0028] See Figure 1 This illustration shows a schematic diagram of a positioning device for deep salt cave microcracks in one embodiment of this application, as shown below. Figure 1 As shown, the device may include at least a surface excitation module 101, a downhole detection module 107, and a surface computing module 103. The surface excitation module 101 is located on the surface and is used to apply low-frequency micro-pressure fluctuation signals into the deep salt cavern 106 and record the phase timestamps corresponding to the low-frequency micro-pressure fluctuation signals. The downhole detection module 107 is connected to the surface excitation module 101 via a cable 105, lowered to the central region of the deep salt cavern 106 via a casing 104, and suspended inside the deep salt cavern 106 by the cable 105. It is used to detect high-frequency acoustic signals generated when gas leaks from the micro-fractures in the deep salt cavern 106 and transmits the high-frequency acoustic signals to the surface computing module. Additionally, brine 108 is stored at the bottom of the deep salt cavern 106. The surface computing module 103 is located on the surface and is communicatively connected to the surface excitation module 101 and the downhole detection module 107. It is used to perform phase-locked amplification processing on the high-frequency acoustic signals to locate the micro-fractures in the deep salt cavern 106.

[0029] In this application, the ground excitation module is located on the surface, specifically at the injection-production manifold of the wellhead of a salt cavern gas storage facility. It does not require deep underground operation and can be used to apply a stable low-frequency micro-pressure fluctuation signal to the interior of deep salt caverns at depths of several thousand meters. This signal is a weak and safe pressure fluctuation that will not cause mechanical damage to the rock mass structure of the salt cavern. At the same time, the module records the phase timestamp corresponding to the applied low-frequency micro-pressure fluctuation signal in real time and accurately. The phase timestamp is a reference for subsequent signal processing and can provide an accurate phase and time reference for signal purification and positioning calculation.

[0030] In this application, the downhole detection module is connected to the ground excitation module by means of a cable. The cable can bear the weight and suspend the module, and stably suspend the downhole detection module in the internal space of the deep salt cavern. It can be used to capture the high-frequency sound wave signal generated when gas leaks from the micro-cracks in the deep salt cavern. This type of signal is an ultrasonic signal generated after the gas passes through the micro-cracks and forms a high-speed airflow. After the module acquires the signal, it will stably transmit it to the ground computing module on the surface.

[0031] In this application, the ground computing module is also deployed on the surface and establishes communication connections with the ground excitation module and the downhole detection module. The ground computing module can use the phase timestamp as a reference to perform phase-locked amplification processing on the high-frequency acoustic signal, remove various random environmental noises in the salt cavern, extract pure leakage characteristic signals, and finally complete the spatial positioning of micro-cracks in deep salt caverns based on the purified signals to determine the specific location of the micro-cracks.

[0032] In this application, the low-frequency micro-pressure fluctuation signal refers to a safe pressure fluctuation signal with extremely low frequency and small amplitude, which will not damage the salt cavern structure and is the core excitation signal for modulating the leakage acoustic signal. Specifically, the frequency can be between 0.01Hz and 0.1Hz, and the amplitude can be between 0.5% and 1% of the working pressure. This application does not make specific limitations on these aspects. The phase timestamp is accurate data recording the phase and corresponding time of the low-frequency micro-pressure fluctuation signal, which can be used as a reference benchmark for phase-locked amplification processing to ensure the synchronization and accuracy of signal processing. The high-frequency acoustic signal is an ultra-high-frequency ultrasonic signal generated by the high-speed airflow rubbing against the microstructure of the salt rock when high-pressure gas passes through micro-cracks in the salt cavern. It is a characteristic signal of micro-crack leakage. The phase-locked amplification processing is a method of noise removal and signal purification of the high-frequency acoustic signal with the phase timestamp as a reference. It can significantly improve the signal-to-noise ratio of the leakage signal and accurately identify leakage characteristics.

[0033] In this application, the ground excitation module can safely apply low-frequency micro-pressure fluctuation signals on the surface and record accurate phase timestamps. The downhole detection module can capture high-frequency acoustic signals generated by leakage throughout the salt cavern. The ground calculation module can combine the phase timestamps to complete phase-locked amplification of the signals and micro-fracture location. It can effectively resist the interference caused by underground temperature and pressure fluctuations and plastic creep of salt rock, and can eliminate various random environmental noises such as rock creep and gas convection in the salt cavern. Thus, it can accurately extract the leakage signals of micro-fractures and complete three-dimensional spatial location, improving the accuracy and reliability of micro-fracture location in deep salt caverns.

[0034] Continue to refer to Figure 1The ground excitation module may include at least a servo fine-tuning pressure valve group, a pressure waveform generator, and a synchronization clock; wherein, the servo fine-tuning pressure valve group can be used to output a low-frequency micro-pressure fluctuation signal; the pressure waveform generator can be used to adjust the fluctuation frequency range and fluctuation amplitude range of the low-frequency micro-pressure fluctuation signal; and the synchronization clock can be used to record the phase timestamp of the low-frequency micro-pressure fluctuation signal.

[0035] In this application, the servo micro-pressure adjustment valve group is the execution component of the ground excitation module. It is connected to an auxiliary booster pump and a vent valve. It can smoothly output low-frequency micro-pressure fluctuation signals to the deep salt cavern through the fine action of micro-injection and venting. The entire adjustment process is smooth and accurate, and will not cause mechanical damage to the rock mass structure of the salt cavern, nor will it interfere with the normal storage state of the gas inside the salt cavern.

[0036] In this application, the pressure waveform generator is a control component of the ground excitation module and belongs to a programmable control device. It can autonomously set and control the fluctuation frequency range and fluctuation amplitude range of the low-frequency micro-pressure fluctuation signal according to the actual working conditions such as the depth, internal pressure, and cavity size of the deep salt cave, so as to lock the signal parameters within an effective and safe range and ensure that the signal can stably modulate the high-frequency sound waves generated by the leakage.

[0037] In this application, the synchronous clock is a reference timing component that can record the phase timestamp corresponding to the low-frequency micro-pressure fluctuation signal output by the servo micro-pressure adjustment valve group in real time and accurately. The timestamp data will be synchronously transmitted to the ground computing module as a reference for subsequent phase-locked amplification processing, ensuring the synchronization and accuracy of the signal processing process.

[0038] In this application, the servo micro-adjustment valve assembly can smoothly output a safe and damage-free low-frequency micro-pressure fluctuation signal. The pressure waveform generator can accurately adjust the frequency and amplitude parameters of the signal according to the actual working conditions. The synchronization clock can record accurate phase timestamps to provide a reliable reference for subsequent signal processing. This combination of components allows the ground excitation module to stably output a controllable excitation signal and provide an accurate reference benchmark, thereby effectively avoiding detection errors caused by unstable signal parameters or reference benchmark deviations, and improving the accuracy of locating micro-cracks in deep salt caverns.

[0039] Continue to refer to Figure 1The downhole detection module may include at least a spherical phased array listening device, a signal processor, and a pressure-bearing sealed chamber. The spherical phased array listening device is located inside the pressure-bearing sealed chamber and can be used to receive high-frequency acoustic signals generated by micro-cracks in the deep salt cavern and transmit the high-frequency acoustic signals to the signal processor. The signal processor can be used to preprocess the high-frequency acoustic signals and transmit the preprocessed high-frequency acoustic signals to the surface computing module. The pressure-bearing sealed chamber can withstand the high temperature and high pressure environment inside the deep salt cavern and protect the signal processor and the spherical phased array listening device.

[0040] In this application, the high-frequency acoustic signal is an ultrasonic signal of 40kHz to 300kHz generated after high-pressure gas in the salt cave passes through microcracks to form a high-speed airflow, and is a characteristic signal of microcrack leakage. Preprocessing refers to the preliminary processing operations of filtering and noise reduction, signal amplification, and digital conversion on the acquired raw acoustic signal.

[0041] In this application, the spherical phased array listening device is installed entirely inside a pressure-bearing sealed chamber. It is cast from a solid spherical structure made of corrosion-resistant and high-pressure-resistant titanium alloy. The surface of the sphere is uniformly distributed with no less than 64 broadband piezoelectric ceramic air or hydrophone nodes according to a mapping matrix of icosahedral subdivision. It can receive sound wave signals from the entire area inside the deep salt cave without dead angles, accurately capture high-frequency sound wave signals generated by leaking airflow in microcracks, and convert the received acoustic signals into electrical signals and stably transmit them to the signal processor.

[0042] In this application, the signal processor integrates a high-pass filter unit and a low-noise preamplifier unit, which can perform preprocessing on the high-frequency acoustic signal transmitted by the spherical phased array monitoring device. The high-pass filter unit cuts off low-frequency mechanical noise and fluid convection noise below 20kHz, and the low-noise preamplifier unit enhances the intensity of the weak high-frequency acoustic signal. After completing the noise reduction and amplification of the signal, the processed signal is converted into a digital signal and transmitted to the ground computing module on the ground in real time.

[0043] In this application, the pressure-bearing sealed chamber adopts an armored pressure-bearing sealed structure design, which can withstand the high pressure environment of more than 20MPa and the high temperature environment of more than 70℃ inside the deep salt cavern. At the same time, the chamber integrates fiber optic gyroscopes, absolute pressure sensors and thermometers, which can provide a sealed and stable working space for the internal spherical phased array listening device and signal processor, avoiding damage to electronic devices caused by the harsh underground environment. It can also collect underground space attitude data, pressure and temperature data, providing auxiliary support for subsequent positioning calculations.

[0044] In this application, the pressure-bearing sealed chamber can adapt to the harsh environment of high temperature and high pressure in deep salt caverns and protect the core detection devices to ensure stable operation. The spherical phased array listening device can realize the reception of high-frequency acoustic signals throughout the salt cavern, thereby eliminating the detection range limitations caused by well wall cables. The signal processor can perform filtering, noise reduction, and amplification preprocessing operations on the original acoustic signal, effectively eliminating interference from random environmental noise such as salt rock creep and gas convection. This structural design allows the downhole detection module to stably acquire pure leakage acoustic signals in complex downhole environments, thereby solving the technical problems of poor anti-interference ability and inability to conduct panoramic detection in existing salt cavern micro-leakage detection technologies. At the same time, it shortens the time spent on signal acquisition and preprocessing, providing a reliable data foundation for the subsequent ground calculation module to accurately locate micro-cracks.

[0045] Continue to refer to Figure 1 The ground computing module may include at least an envelope detector, a lock-in amplifier, and a positioning device. The envelope detector can be used to perform Hilbert transform processing on the high-frequency acoustic signal to obtain envelope signals with multiple frequency ranges. The lock-in amplifier can be used to perform lock-in amplification processing on the envelope signals to obtain leakage acoustic signals. The positioning device can be used to locate microcracks in the deep salt cavern.

[0046] In this application, the envelope detector is a signal processing component used to perform Hilbert transform on high-frequency acoustic signals to extract the amplitude envelope signal, which can regulate signal characteristics and highlight the variation law of leakage signals. The Hilbert transform processing is a commonly used mathematical signal processing method used to extract the amplitude envelope from high-frequency composite acoustic signals, providing basic data for subsequent signal purification. The envelope signal is a characteristic signal reflecting the amplitude variation law of high-frequency acoustic signals, which can fully reflect the modulation characteristics of leakage acoustic signals. The lock-in amplifier is a core processing component that uses phase timestamps as a reference to perform noise removal and signal enhancement on the envelope signal, which can significantly improve the signal-to-noise ratio of leakage signals. The leakage acoustic signal is a pure high-frequency acoustic signal generated by microcrack leakage and modulated by low-frequency micro-pressure fluctuations after removing all environmental noise. The positioning device is a component that calculates and determines the spatial coordinates of microcracks based on phased array beamforming algorithms, which can realize three-dimensional panoramic positioning of microcracks.

[0047] In this application, the envelope detector, as the front-end signal processing component of the ground computing module, is mainly used to perform Hilbert transform on the received high-frequency acoustic signal. Through this mathematical processing, the amplitude envelope signal corresponding to different frequency ranges is extracted to remove the messy interference components in the high-frequency acoustic signal, clearly present the amplitude variation law of the signal, and highlight the characteristic information of the leaked acoustic wave. The specific processing frequency range can cover 40kHz to 300kHz, or a preferred frequency band of 50kHz to 150kHz can be selected according to the actual background noise situation downhole, providing regular basic data for subsequent signal purification work.

[0048] In this application, the lock-in amplifier is a purification component of the ground computing module. Using the phase timestamp recorded by the synchronous clock in the ground excitation module as a reference, it performs lock-in amplification processing on the envelope signals of each frequency band output by the envelope detector. Through a combination of mixing and ultra-narrowband digital low-pass filtering, it removes interference components such as random noise, thermal noise, and rock creep noise that do not have low-frequency micro-pressure fluctuation rhythm in the signal, significantly improving the signal-to-noise ratio of the leakage signal and obtaining a pure leakage acoustic signal modulated by the low-frequency micro-pressure fluctuation signal.

[0049] In this application, the positioning device is the terminal execution component of the ground computing module. It can calculate the time difference and phase difference of the pure leakage acoustic wave signal output by the lock-in amplifier to reach different sensing nodes of the spherical phased array listening device. It uses the phased array beamforming synthetic aperture algorithm to perform reverse addressing calculation to obtain the pitch angle, azimuth angle and radial vector of the microcrack in the salt cave coordinate system. Then, it performs spatial matching with the three-dimensional geometric shape model of the salt cave to determine the specific spatial location of the microcrack on the inner wall of the salt cave.

[0050] In this application, the envelope detector can perform Hilbert transform processing on high-frequency acoustic signals and extract envelope signals of different frequency ranges, laying a solid foundation for subsequent signal purification. The lock-in amplifier can perform lock-in amplification processing on the envelope signals based on the phase timestamp, effectively eliminating various random environmental noises caused by salt rock creep, geothermal fluctuations, gas convection, etc., thereby solving the problems of easy interference and signal extraction distortion in existing technologies. The positioning device can complete the three-dimensional spatial calculation and accurate positioning of micro-fractures based on pure leakage acoustic signals, freeing itself from the constraints of wellbore cables to achieve full-area positioning of salt caverns without blind spots. At the same time, the entire signal processing flow is simple and efficient, which can significantly shorten the overall time of detection operations. This structural setup allows the ground computing module to complete the entire process from signal purification to spatial positioning, thereby solving the technical problems of long detection time, poor anti-interference ability, and inability to accurately locate panoramic micro-leakage in existing salt cavern detection technologies, and improving the accuracy and reliability of deep salt cavern micro-fracture positioning.

[0051] Next, we will combine Figure 2The method for locating microcracks in deep salt caves proposed in this application is described in detail.

[0052] See Figure 2 The flowchart illustrates a method for locating microfractures in deep salt caverns according to one embodiment of this application. The method is performed on the apparatus described above and may include at least the following steps 210 to 230: Step 210: Apply a low-frequency micro-pressure fluctuation signal to the interior of the deep salt cave through the ground excitation module, and record the phase timestamp corresponding to the low-frequency micro-pressure fluctuation signal.

[0053] Step 220: Receive the high-frequency acoustic signal generated by the micro-fractures in the deep salt cavern through the downhole detection module, and transmit the high-frequency acoustic signal to the surface computing module.

[0054] Step 230: Based on the phase timestamp, the high-frequency acoustic signal is amplified by the ground calculation module to locate the microcracks in the deep salt cave.

[0055] In this application, the low-frequency micro-pressure fluctuation signal is a low-frequency, small-amplitude safe pressure signal output by the ground excitation module, with a frequency range between 0.01Hz and 0.1Hz. Its amplitude will not cause mechanical damage to the salt cavern rock structure and can be used to synchronously modulate the leakage acoustic signal. The phase timestamp is accurate data of the phase and corresponding time of the low-frequency micro-pressure fluctuation signal recorded by the synchronous clock, which can be used as a reference for phase-locked amplification processing. The high-frequency acoustic signal is an ultrasonic signal generated by high-pressure gas passing through micro-cracks in the salt cavern to form a high-speed airflow, with a frequency range of 40kHz to 300kHz, and is a characteristic signal of micro-crack leakage. The phase-locked amplification processing, using the phase timestamp as a reference, removes environmental noise and purifies the leakage signal, which can significantly improve the signal-to-noise ratio.

[0056] In this application, the operation is initiated by a surface excitation module located at the wellhead. This module, through its internal servo micro-pressure adjustment valve assembly and pressure waveform generator, applies a low-frequency micro-pressure fluctuation signal with controllable frequency and amplitude to the deep salt cavern at a depth of several kilometers. This signal can synchronously modulate the high-frequency acoustic waves generated by micro-fracture leakage within the salt cavern. Simultaneously, the synchronization clock in the surface excitation module records the phase timestamp corresponding to the low-frequency micro-pressure fluctuation signal in real time, providing a reference for subsequent signal processing. Subsequently, signal acquisition is carried out by a downhole detection module suspended at the geometric center of the deep salt cavern. The spherical phased array listening device inside the module receives the omnidirectional high-frequency acoustic wave signal generated by the friction of the leaking gas from the micro-fracture with the salt rock. The signal processor performs preprocessing on the signal, including filtering, noise reduction, and amplification, before stably transmitting the processed high-frequency acoustic wave signal to the surface computing module. Finally, the ground-based computing module performs the core processing operations. Using the phase timestamp transmitted by the ground excitation module as an absolute reference, the module performs phase-locked amplification on the received high-frequency acoustic signal, removes random environmental noise such as salt rock creep, gas convection, and mechanical operation, and extracts the pure leakage acoustic signal modulated only by low-frequency micro-pressure fluctuation signals. Based on this signal, the module completes the three-dimensional spatial calculation of the micro-cracks and finally determines the specific location of the micro-cracks in the deep salt cavern.

[0057] In this application, by relying on the ground excitation module to apply a controllable low-frequency micro-pressure fluctuation signal and record the phase timestamp, the leakage acoustic signal can be given specific modulation characteristics, thereby distinguishing it from random environmental noise. The downhole detection module can collect high-frequency acoustic signals throughout the salt cavern, thus overcoming the detection range limitations imposed by wellbore cables. The ground calculation module can perform signal purification and micro-fracture location based on the phase timestamp, resisting detection interference caused by factors such as salt rock plastic creep and geothermal gradient fluctuations. This allows for rapid completion of micro-fracture detection and location operations, solving the technical problems of existing salt cavern micro-leakage detection technologies, such as long processing time, poor anti-interference ability, and inability to accurately locate micro-fractures in a panoramic view, thereby improving the accuracy and detection efficiency of deep salt cavern micro-fracture location.

[0058] In step 210 above, the application of a low-frequency micro-pressure fluctuation signal to the interior of the deep salt cave via the ground excitation module and the recording of the phase timestamp corresponding to the low-frequency micro-pressure fluctuation signal can be specifically performed according to steps 211 to 213 below: Step 211: Generate a preset control signal through a pressure waveform generator and transmit the preset control signal to the servo fine-tuning pressure valve group.

[0059] Step 212: Based on the preset control signal, control the servo micro-pressure adjustment valve group to apply a low-frequency micro-pressure fluctuation signal with a preset frequency and preset amplitude to the interior of the deep salt cave.

[0060] Step 213: Record the phase timestamp of the low-frequency micro-voltage fluctuation signal using a synchronized clock.

[0061] In this application, the preset control signal is a control command generated by a pressure waveform generator based on the actual working conditions of the salt cavern. It includes the frequency and amplitude parameters of a low-frequency micro-pressure fluctuation signal, used to accurately control the action of the servo micro-pressure adjustment valve assembly. The preset frequency is a pre-set frequency value of the low-frequency micro-pressure fluctuation signal, ranging from 0.01Hz to 0.1Hz, adapting to the modulation requirements of leakage sound waves. The preset amplitude is a pre-set pressure change value of the low-frequency micro-pressure fluctuation signal, ranging from 0.05MPa to 0.2MPa, ensuring the safety of signal application. The low-frequency micro-pressure fluctuation signal is a low-frequency, small-amplitude, safe alternating pressure signal that can synchronously modulate the high-frequency sound wave signal generated by micro-crack leakage. The phase timestamp is accurate data of the phase and corresponding time of the fluctuation signal recorded by a synchronous clock, providing a reference for phase-locked amplification processing. The servo micro-pressure adjustment valve assembly is a pressure regulating component composed of a precision servo valve, an auxiliary booster pump, and a vent valve. The pressure waveform generator is a programmable control device capable of generating and outputting control signals with specified parameters. The synchronous clock is a reference timing component used to record the phase and time information of the fluctuating signal.

[0062] In this application, the pressure waveform generator in the ground excitation module first generates a corresponding preset control signal based on actual operating parameters such as the cavity size, internal working pressure, and downhole ambient temperature of the deep salt cavern to be detected. The preset control signal includes the core parameters of frequency and amplitude of low-frequency micro-pressure fluctuation signal. After generation, it is transmitted to the servo micro-pressure adjustment valve group in real time to provide corresponding control commands for the valve group's operation. Subsequently, the servo micro-pressure adjustment valve group will operate according to the received preset control signal, performing micro-injection of gas through the matching auxiliary booster pump and micro-venting through the vent valve, so as to smoothly and controllably introduce gas into the deep salt cavern. A low-frequency micro-pressure fluctuation signal that meets the preset frequency and amplitude requirements is applied to the salt cavern rock mass. The application of this signal will not cause mechanical damage to the salt cavern rock mass structure, nor will it affect the normal storage state of the gas inside the salt cavern. At the same time, it can synchronously modulate the high-frequency acoustic wave signal generated by the leakage of micro-cracks in the salt cavern. Finally, the high-precision timing operation is started by the synchronous clock in the ground excitation module, which records the phase change and corresponding time information of the low-frequency micro-pressure fluctuation signal output by the servo micro-pressure adjustment valve group in real time and accurately, forming a complete phase timestamp. This data will be synchronously transmitted to the ground calculation module as a reference for subsequent phase-locked amplification processing.

[0063] In this application, the pressure waveform generator can generate a preset control signal according to the actual working conditions of the salt cavern. The servo micro-adjustment valve group can output a stable and safe low-frequency micro-pressure fluctuation signal based on the control signal. The synchronous clock can record accurate phase timestamps. This step-by-step operation can make the modulation effect of the low-frequency micro-pressure fluctuation signal more stable and effective, thereby avoiding detection errors caused by signal parameter deviations or inaccurate reference standards. This effectively resists the interference caused by plastic creep of salt rock and geothermal fluctuations. At the same time, it simplifies the signal application process and shortens the overall detection time, providing reliable support for the subsequent accurate extraction of leakage signals and location of micro-cracks. This solves the technical problems of long detection time and poor anti-interference ability in existing salt cavern micro-leakage detection technology.

[0064] In step 220 above, the high-frequency acoustic signal generated by the micro-fractures in the deep salt cavern is received by the downhole detection module, which can be specifically executed according to steps 221 to 223 as follows: Step 221: Receive the composite acoustic wave signal from the deep salt cave using a spherical phased array listening device.

[0065] Step 222: The signal processor filters out noise below the preset frequency band threshold to obtain a high-frequency signal.

[0066] Step 223: The high-frequency signal is amplified by the signal processor to obtain a high-frequency sound wave signal.

[0067] In this application, the spherical phased array listening device is an omnidirectional acoustic wave acquisition device employing a solid titanium alloy spherical structure and equipped with multiple broadband piezoelectric sensing nodes, capable of receiving acoustic wave signals throughout the salt cavern area. The composite acoustic wave signal is a collection of various acoustic waves simultaneously existing within the salt cavern, including high-frequency ultrasonic waves generated by micro-fracture leakage and various downhole environmental noises. The preset frequency band threshold is a pre-set filtering critical frequency, typically 20kHz, used to distinguish between low-frequency interference signals and high-frequency leakage characteristic signals. The high-frequency signal is an acoustic wave signal between 40kHz and 300kHz retained after filtering out low-frequency noise. The high-frequency acoustic wave signal is a pure high-frequency signal after noise removal and amplification, and is a characteristic signal of micro-fracture leakage. The signal processor is a downhole signal processing device integrating high-pass filtering and low-noise amplification functions, used to complete the preprocessing of the acoustic wave signal.

[0068] In this application, the spherical phased array listening device in the downhole detection module first receives the acoustic signals. This device employs a corrosion-resistant and high-pressure-resistant solid titanium alloy sphere structure, with multiple broadband piezoelectric ceramic sensing nodes evenly distributed on its surface. The entire device is suspended at the geometric center of the deep salt cavern, enabling acoustic wave acquisition across the entire interior of the cavern. It receives composite acoustic signals including ultrasonic waves from micro-fracture leaks, downhole gas convection noise, salt rock creep and spalling noise, and downhole mechanical operating noise, without being limited by the detection range of the wellbore cable. Subsequently, a signal processor performs noise filtering. The signal processor integrates a high-pass filter unit, which filters the composite acoustic signals according to a pre-set frequency threshold, removing low-frequency interference signals below that threshold. These low-frequency interference signals are mostly irregular environmental noise from downhole and are unrelated to the characteristic signals of micro-fracture leaks. After filtering, a high-frequency signal retaining the high-frequency characteristics is obtained. Finally, the signal processor amplifies the initially selected high-frequency signals, using an internal low-noise preamplifier unit to enhance the strength of the weak high-frequency signals and prevent signal attenuation or distortion during transmission. After processing, a high-frequency sound wave signal that meets the requirements for transmission and processing is obtained, and then the signal is stably transmitted to the ground computing module.

[0069] In this application, the spherical phased array listening device can receive composite acoustic signals from inside the salt cavern in all directions, thereby achieving full-area acquisition of the salt cavern. The signal processor can filter out irregular low-frequency noise below the preset frequency band threshold and amplify the high-frequency signal, effectively eliminating interference from environmental noise such as salt rock creep and gas convection, and improving the purity and intensity of the high-frequency acoustic signal. This allows for rapid screening and enhancement of downhole signals, solving the technical problems of poor anti-interference ability and incomplete signal acquisition in existing salt cavern micro-leakage detection technologies. At the same time, it shortens the overall time of signal preprocessing, providing stable data support for the subsequent ground calculation module to accurately extract leakage signals and locate micro-cracks.

[0070] In step 230 above, the step of locating the microcracks in the deep salt cave by performing phase-locked amplification on the high-frequency acoustic signal based on the phase timestamp using a ground calculation module can be specifically executed according to steps 231 to 233 as follows: Step 231: Perform Hilbert transform on the high-frequency acoustic signal using an envelope detector to obtain envelope signals with multiple frequency ranges.

[0071] Step 232: Based on the phase timestamp, the envelope signals of each frequency range are subjected to phase-locked amplification processing to obtain multiple leakage acoustic wave signals.

[0072] Step 233: Using a positioning device, determine the location of the microcracks corresponding to each leakage acoustic signal in the deep salt cavern.

[0073] In this application, the Hilbert transform processing is a mathematical signal processing method that extracts the amplitude envelope from a high-frequency composite acoustic signal. This method can regulate signal characteristics and retain the modulation information of the leakage signal. The envelope signal is a characteristic signal reflecting the amplitude variation law of the high-frequency acoustic signal and carries the modulation characteristics of the microcrack leakage signal. The phase-locked amplification processing uses a phase timestamp as a reference to eliminate environmental noise and purify the leakage signal, which can significantly improve the signal-to-noise ratio of the leakage signal. The leakage acoustic signal is a pure high-frequency signal that, after phase-locked amplification processing, eliminates interference and retains the microcrack leakage characteristics. The positioning device is a component that completes the spatial calculation and model registration of the microcrack based on a phased array beamforming algorithm, and can locate the position of the microcrack in a deep salt cavern.

[0074] In this application, the envelope detector in the ground computing module first performs Hilbert transform processing on the high-frequency acoustic signal transmitted from the downhole detection module. This extracts the amplitude envelope signals corresponding to different frequency ranges from the composite high-frequency acoustic signal, removing stray interference components and clearly revealing the amplitude variation pattern of the high-frequency acoustic signal. It also preserves the characteristic information of the leakage signal being modulated by low-frequency micro-pressure fluctuations. The processed frequency range can cover 40kHz to 300kHz, or a preferred frequency band of 50kHz to 150kHz can be selected based on the actual background noise in the well. Subsequently, using the phase timestamp recorded by the ground excitation module as the sole absolute reference, phase-locked amplification processing is performed on the envelope signals of each frequency range. This process matches the envelope signal with the reference signal corresponding to the phase timestamp, eliminating all interference components such as random noise, thermal noise, and salt creep noise that do not possess low-frequency modulation characteristics. Finally, multiple pure leakage acoustic signals retaining only the leakage characteristics are obtained, enabling synchronous purification of leakage signals across multiple frequency bands. Finally, the positioning device in the ground computing module completes the position calculation. The positioning device obtains the time difference and phase difference of the leakage acoustic wave signals received by each sensing node in the spherical phased array listening device. It uses the phased array beamforming synthetic aperture algorithm to perform reverse addressing calculation, calculates the spatial parameters of the microcracks in the salt cave coordinate system, and then spatially registers the calculation results with the three-dimensional geometric morphology model of the salt cave to accurately determine the specific location of the microcracks corresponding to each leakage acoustic wave signal on the inner wall of the deep salt cave.

[0075] In this application, the envelope detector can perform Hilbert transform processing on high-frequency acoustic signals and extract multi-band envelope signals, providing regular basic data for subsequent leakage signal purification. The phase-locked amplification processing can eliminate random environmental noise such as salt rock plastic creep, geothermal fluctuations, and gas convection based on phase timestamp frequency bands, thereby effectively solving the problem of interference susceptibility in existing detection technologies. The positioning device can complete the three-dimensional spatial calculation and model registration of micro-cracks based on pure leakage acoustic signals, freeing itself from the constraints of wellbore cables to achieve accurate positioning of the entire salt cavern. At the same time, the entire processing flow is simple and efficient, which can significantly shorten the overall time of detection operations. This step-by-step processing setting allows the ground computing module to complete the entire process from signal purification to spatial positioning, thereby solving the technical problems of long detection time, poor anti-interference ability, and inability to accurately locate panoramic micro-leakage in existing salt cavern detection technologies, and improving the accuracy of deep salt cavern micro-crack positioning.

[0076] In step 232 above, the envelope signals of each frequency range are subjected to phase-locked amplification to obtain multiple leakage acoustic wave signals. Specifically, this can be performed according to steps 2321 to 2322 below: Step 2321: Mix the envelope signals of each frequency range with the phase timestamp to obtain a mixed signal.

[0077] Step 2322: Remove random errors in the mixing signal by digital low-pass filtering to obtain multiple leakage acoustic wave signals.

[0078] In this application, the envelope signal is a high-frequency acoustic amplitude variation signal extracted after Hilbert transform processing, retaining the characteristic information of the micro-fracture leakage signal modulated by low-frequency pressure fluctuations. The phase timestamp is the accurate phase and time data of the low-frequency micro-pressure fluctuation signal recorded by the synchronous clock of the ground excitation module, and is the sole absolute reference for phase-locked amplification processing. The mixing processing is a signal processing method that couples the envelope signal with the reference signal corresponding to the phase timestamp, used to enhance the characteristics of the leakage signal. The digital low-pass filtering is a processing method that uses an extremely narrow-band filtering path to remove high-frequency stray components, used to remove random errors in the signal. The random errors are irregular interference components such as thermal noise, fluid noise, and salt creep noise existing in the downhole environment. The leakage acoustic signal is a pure high-frequency signal that, after mixing and filtering processing, removes all interference and retains only the micro-fracture leakage characteristics.

[0079] In this application, envelope signals of different frequency ranges are first mixed with reference signals corresponding to phase timestamps. The core of the mixing process is to perform synchronous coupling operations between the envelope signals and the reference signals, thereby enhancing and highlighting the leakage characteristics modulated by the low-frequency micro-pressure fluctuation signals applied by the surface excitation module. Meanwhile, various irregular interference signals existing in the downhole environment will form unrelated stray components with the reference signals, facilitating subsequent separation and removal. After obtaining the mixed signal through the mixing process, the mixed signal can be further purified by digital low-pass filtering. Specifically, an ultra-narrowband digital low-pass filter can be used to filter out random errors in the mixed signal. These random errors mainly include downhole thermal noise, irregular fluid noise, noise generated by salt rock creep and rock fragmentation, and mechanical operation interference, which are interference components that do not possess low-frequency modulation characteristics. After filtering, multiple pure leakage acoustic signals with different frequency ranges are finally obtained, which can fully cover the ultrasonic frequency band generated by micro-fracture leakage.

[0080] In this application, by mixing the envelope signals of various frequency ranges with the phase timestamps and using digital low-pass filtering to remove random errors in the mixed signals, the modulation characteristics of the microcrack leakage signal can be fully enhanced. At the same time, various random interferences caused by salt rock plastic creep, geothermal gradient fluctuations, and irregular gas convection can be accurately eliminated. This effectively solves the problem that leakage signals are easily masked by noise and real leaks cannot be identified in existing salt cavern micro-leakage detection technologies. This significantly improves the signal-to-noise ratio of the leakage signal, provides pure and reliable data support for subsequent spatial positioning of microcracks, and also speeds up the signal purification process and shortens the overall detection time.

[0081] In step 233 above, the location of the microcracks corresponding to each leakage acoustic signal in the deep salt cavern is determined by the positioning device, which can be specifically performed according to steps 2331 to 2332 as follows: Step 2331: Obtain the time difference between the times when each listening probe in the spherical phased array listening device receives the leaked acoustic wave signal, and obtain the phase difference when each listening probe receives the leaked acoustic wave signal.

[0082] Step 2332: Based on the time difference and the phase difference, the location of the microcrack corresponding to the leakage acoustic signal in the deep salt cave is calculated by using a phased array beamforming synthetic aperture algorithm.

[0083] In this application, the time difference and phase difference of the leakage acoustic wave signal received by each listening probe in the spherical phased array listening device are first obtained. The spherical phased array listening device adopts a solid spherical structure, and multiple listening probes are arranged on the surface in a distribution pattern with equal solid angles. The leakage acoustic wave signal emitted by the microcrack propagates in the high-pressure gas inside the salt cavern. The time when it arrives at the listening probes at different positions will have slight differences. This difference is the time difference. At the same time, the waveform phase when the signal arrives at each listening probe will also have corresponding differences. This difference is the phase difference. After obtaining the time difference and phase difference, the positioning device will substitute the two types of data into the phased array beamforming synthetic aperture algorithm for calculation. This algorithm will perform reverse addressing calculation based on the spatial distribution characteristics of the spherical array, and gradually deduce the pitch angle, azimuth angle and radial distance of the microcrack corresponding to the leakage acoustic wave signal relative to the listening device. Then, combined with the three-dimensional geometric morphology model of the salt cavern, spatial registration is completed, and finally the specific location of the microcrack in the deep salt cavern is determined, realizing the accurate positioning of the microcrack.

[0084] In this application, by obtaining the time difference and phase difference of the leakage acoustic wave signals received by each listening probe in the spherical phased array listening device, and using the phased array beamforming synthetic aperture algorithm to calculate the location of microcracks based on this data, the advantages of omnidirectional acquisition by the spherical array can be fully utilized to accurately determine the three-dimensional spatial coordinates of microcracks in the salt cavern. This overcomes the detection range limitations imposed by the well wall cable and achieves full-coverage positioning of the inner wall of the salt cavern. At the same time, the calculation process relies on the purified leakage acoustic wave signal, which can effectively resist the interference caused by the plastic creep of salt rock and geothermal fluctuations, avoiding the situation of ambiguous or false positioning. This solves the technical problems of existing salt cavern micro-leakage detection technology, such as the inability to accurately locate the entire panorama and the blindness of the detection results. It also simplifies the positioning calculation process, shortens the overall detection time, and improves the accuracy of locating microcracks in deep salt caverns.

[0085] Based on the technical solution proposed in this application, the ground excitation module can safely apply low-frequency micro-pressure fluctuation signals on the surface and record accurate phase timestamps. The downhole detection module can capture high-frequency acoustic signals generated by leakage throughout the salt cavern. The ground calculation module can combine the phase timestamps to complete the phase-locked amplification processing of the signals and the location of micro-cracks. It can effectively resist the interference caused by underground temperature and pressure fluctuations and plastic creep of salt rock, and can eliminate various random environmental noises such as rock creep and gas convection in the salt cavern. Thus, it can accurately extract the leakage signals of micro-cracks and complete three-dimensional spatial positioning, improving the accuracy and reliability of micro-crack positioning in deep salt caverns.

[0086] As another embodiment of this application, a computer program product or computer program is also provided, which includes computer instructions stored in a computer-readable storage medium. A processor of a computer device reads the computer instructions from the computer-readable storage medium and executes the computer instructions, causing the computer device to perform the methods described in the above embodiments.

[0087] As another embodiment of this application, a computer-readable storage medium is also provided. This computer-readable storage medium may be included in the electronic device described in the above embodiments; or it may exist independently and not assembled into the electronic device. The aforementioned computer-readable storage medium carries one or more programs, which, when executed by the electronic device, cause the electronic device to perform the methods described in the above embodiments.

[0088] Based on the same inventive concept, embodiments of this application also provide an electronic device. (Reference) Figure 3 The diagram illustrates the structure of an electronic device according to one embodiment of this application. The electronic device includes one or more memories 304, one or more processors 302, and at least one computer program (program code) stored in the memories 304 and executable on the processors 302. When the processors 302 execute the computer program, they implement the method described above.

[0089] Among them, Figure 3 In this document, a bus architecture (represented by bus 300) is used. Bus 300 may include any number of interconnected buses and bridges, linking various circuits including one or more processors represented by processor 302 and memory represented by memory 304. Bus 300 may also link various other circuits such as peripheral devices, voltage regulators, and power management circuits, which are well known in the art and therefore will not be described further herein. Bus interface 305 provides an interface between bus 300 and receiver 301 and transmitter 303. Receiver 301 and transmitter 303 may be the same element, i.e., a transceiver, providing a unit for communicating with various other devices over a transmission medium. Processor 302 is responsible for managing bus 300 and general processing, while memory 304 can be used to store data used by processor 302 during operation.

[0090] The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored as one or more instructions or codes on or transmitted via a computer-readable medium. Other examples and embodiments are within the scope and spirit of this application and the appended claims. For example, due to the nature of software, the functions described above may be implemented using software executed by a processor, hardware, firmware, hardwired, or any combination thereof. Furthermore, the functional units may be integrated into a single processing unit, or each unit may exist physically separately, or two or more units may be integrated into a single unit.

[0091] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. The device embodiments described above are merely illustrative; for example, the division of units can be a logical functional division, and in actual implementation, there may be other division methods. For instance, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual coupling, direct coupling, or communication connection may be through some interfaces; the indirect coupling or communication connection between units or modules may be electrical or other forms.

[0092] The units described as separate components may or may not be physically separate. Similarly, the components of the control device may or may not be physical units; they may be located in one place or distributed across multiple units. Some or all of the units can be selected to achieve the purpose of this embodiment, depending on actual needs.

[0093] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as a USB flash drive, read-only memory (ROM), random access memory (RAM), portable hard drive, magnetic disk, or optical disk.

[0094] The above description is merely an embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A positioning device for microcracks in deep salt caverns, characterized in that, The device includes: A ground-based excitation module, located on the ground surface, is used to apply low-frequency micro-pressure fluctuation signals into the deep salt cavern and record the phase timestamps corresponding to the low-frequency micro-pressure fluctuation signals. The downhole detection module is connected to the surface excitation module via a cable and is suspended inside the deep salt cavern via the cable. It is used to detect the high-frequency acoustic signal generated when gas leaks from the microcracks in the deep salt cavern and transmit the high-frequency acoustic signal to the surface computing module. A ground computing module, located on the surface and communicating with the ground excitation module and the downhole detection module, is used to perform phase-locked amplification processing on the high-frequency acoustic signal to locate micro-fractures in the deep salt cavern.

2. The apparatus according to claim 1, characterized in that, The ground-based excitation module includes: Servo-controlled fine-tuning valve assembly is used to output low-frequency micro-pressure fluctuation signals; A pressure waveform generator is used to adjust the fluctuation frequency range and fluctuation amplitude range of the low-frequency micro-pressure fluctuation signal; A synchronous clock is used to record the phase timestamp of low-frequency micro-voltage fluctuation signals.

3. The apparatus according to claim 2, characterized in that, The downhole detection module includes a spherical phased array listening device, a signal processor, and a pressure-bearing sealed chamber. The spherical phased array listening device is located inside the pressure-bearing sealed chamber and is used to receive high-frequency sound wave signals generated by microcracks in the deep salt cavern and transmit the high-frequency sound wave signals to the signal processor. The signal processor is used to preprocess the high-frequency acoustic signal and transmit the preprocessed high-frequency acoustic signal to the ground computing module. The pressure-bearing sealed chamber is used to withstand the high temperature and high pressure environment inside the deep salt cave, protecting the signal processor and the spherical phased array listening device.

4. The apparatus according to claim 3, characterized in that, The ground computing module includes: An envelope detector is used to perform Hilbert transform processing on the high-frequency acoustic signal to obtain envelope signals in multiple frequency ranges. A lock-in amplifier is used to perform lock-in amplification on the envelope signal to obtain a leakage acoustic wave signal; A positioning device for locating microcracks in the deep salt cavern.

5. A method for locating microcracks in deep salt caverns, characterized in that, The method is applied to the apparatus of claim 4, the method comprising: A low-frequency micro-pressure fluctuation signal is applied to the interior of the deep salt cave through a ground excitation module, and the phase timestamp corresponding to the low-frequency micro-pressure fluctuation signal is recorded. The downhole detection module receives high-frequency acoustic signals generated by micro-fractures in the deep salt cavern and transmits the high-frequency acoustic signals to the surface computing module. Based on the phase timestamp, the high-frequency acoustic signal is amplified by a ground-based computing module to locate microcracks in the deep salt cave.

6. The method according to claim 5, characterized in that, The step of applying a low-frequency micro-pressure fluctuation signal to the interior of the deep salt cave via a ground excitation module and recording the phase timestamp corresponding to the low-frequency micro-pressure fluctuation signal includes: A preset control signal is generated by a pressure waveform generator and transmitted to a servo fine-tuning valve group. Based on the preset control signal, the servo micro-pressure adjustment valve group is controlled to apply a low-frequency micro-pressure fluctuation signal with a preset frequency and preset amplitude to the interior of the deep salt cave. The phase timestamp of the low-frequency micro-voltage fluctuation signal is recorded by synchronizing the clock.

7. The method according to claim 5, characterized in that, The process of receiving high-frequency acoustic signals generated by microfractures in deep salt caverns via a downhole detection module includes: The composite acoustic wave signal from the deep salt cave is received by a spherical phased array listening device. A high-frequency signal is obtained by filtering out noise below a preset frequency threshold using a signal processor. The high-frequency signal is amplified by the signal processor to obtain a high-frequency sound wave signal.

8. The method according to claim 7, characterized in that, The step of locating micro-cracks in deep salt caves by performing phase-locked amplification on the high-frequency acoustic signal using a ground-based computing module based on the phase timestamp includes: The high-frequency acoustic signal is processed by Hilbert transform using an envelope detector to obtain envelope signals in multiple frequency ranges. Based on the phase timestamp, the envelope signals of each frequency range are subjected to phase-locked amplification to obtain multiple leakage acoustic wave signals. The location of the microcracks corresponding to each leakage acoustic signal in the deep salt cavern is determined by the positioning device.

9. The method according to claim 8, characterized in that, The envelope signals of each frequency range are subjected to phase-locked amplification to obtain multiple leakage acoustic wave signals, including: The envelope signals of each frequency range are mixed with the phase timestamp to obtain a mixed signal; Random errors in the mixing signal are removed by digital low-pass filtering to obtain multiple leakage acoustic wave signals.

10. The method according to claim 8, characterized in that, The step of determining the location of the microcracks corresponding to each leakage acoustic signal in the deep salt cavern using a positioning device includes: The time difference between the times when each listening probe in the spherical phased array listening device receives the leaked acoustic wave signal is obtained, and the phase difference when each listening probe receives the leaked acoustic wave signal is obtained. Based on the time difference and the phase difference, the location of the microcrack corresponding to the leakage acoustic signal in the deep salt cave is calculated by the phased array beamforming synthetic aperture algorithm.

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