A downhole acoustic signal adaptive enhancement and intelligent storage and transmission method and system

Abstract

The application discloses an adaptive enhancement and intelligent storage and transmission method and system of a downhole acoustic signal, and belongs to the technical field of oil exploration and development. In view of the problems of low signal-to-noise ratio and huge data volume of the acoustic signal in a complex downhole environment, a closed-loop automatic gain control and temperature-eccentricity double-factor coupled automatic delay control mechanism is designed, and dynamic compensation of signal amplitude and arrival time is realized; an adaptive data compression algorithm and a dynamic hierarchical storage strategy based on signal value are adopted, so that the data volume is greatly reduced on the premise that key information is not lost; and a data label index and an on-demand acquisition mechanism are introduced, so that the data retrieval efficiency and system response speed are improved. The application effectively solves the problems of unstable signal quality and great storage and transmission pressure in the prior art, significantly improves the accuracy and reliability of acoustic logging evaluation, and is suitable for a complex downhole environment with high temperature, high pressure and strong interference.

Description

Technical Field

[0001] This application relates to the field of oil exploration and development, and in particular to a method and system for adaptive enhancement and intelligent storage and transmission of downhole acoustic signals. Background Technology

[0002] In oil and gas well logging evaluation operations, sonic logging is one of the most commonly used techniques. With the large-scale development of deep wells, ultra-deep wells, and shale gas horizontal wells, the downhole environment is becoming increasingly complex. Existing sonic logging systems have revealed serious deficiencies in signal processing and data management: drastic changes in downhole temperature and instrument eccentricity can cause significant fluctuations in sonic signal amplitude and first wave arrival time deviation, severely reducing the signal-to-noise ratio and measurement accuracy; at the same time, the total amount of sonic data is enormous, and traditional full-volume storage and transmission methods not only occupy a large amount of storage space but also result in excessively long data upload times, failing to meet the needs of rapid on-site evaluation.

[0003] In summary, existing technologies cannot simultaneously meet the dual requirements of high signal-to-noise ratio signal acquisition and efficient data storage and transmission in complex downhole environments, and cannot adapt to the demands of modern oil and gas exploration and development for logging efficiency and accuracy. Therefore, improvements are needed. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this application provides a method and system for adaptive enhancement and intelligent storage and transmission of downhole acoustic signals, aiming to solve the aforementioned problems.

[0005] A method for adaptive enhancement and intelligent storage and transmission of downhole acoustic signals for the above-mentioned system includes the following steps:

[0006] S1 signal preprocessing: Filtering and denoising the acquired raw acoustic signal;

[0007] S2 Adaptive Gain Control: Adjusts the amplifier gain in real time according to the signal amplitude to keep the output signal amplitude stable within the preset range;

[0008] S3 dual-factor delay compensation: calculates and adjusts the hardware delay time of acoustic wave transmission and reception in real time based on downhole temperature and instrument eccentricity;

[0009] S4 Adaptive Data Compression: Adaptive data compression algorithm is used to compress the processed full-wavelength acoustic data in real time;

[0010] S5 Intelligent Hierarchical Storage: The compressed data is classified and stored according to the signal value, and data tags are added to create an index;

[0011] S6 On-Demand Data Transmission: Selectively transmits specified data according to instructions from the host computer.

[0012] By adopting the above technical solution, this method executes in the logical sequence of signal enhancement, data compression, intelligent storage, and on-demand transmission. Each step can dynamically adjust parameters according to real-time downhole conditions, forming a complete closed-loop control system. This method has a clear process, low computational load, and is suitable for implementation in downhole embedded systems. It can significantly improve the system's operating efficiency and reliability while ensuring measurement accuracy.

[0013] Optionally, in step S3, the total delay compensation amount of the temperature-eccentric dual-factor coupled delay compensation is obtained by multiplying the delay change caused by temperature by the temperature compensation coefficient and adding the delay change caused by eccentricity by the eccentricity compensation coefficient.

[0014] By adopting the above technical solution, the total delay compensation is obtained by multiplying the delay changes caused by temperature and eccentricity by their respective compensation coefficients and then summing them. This calculation method has simple logic and low computational load, and can be executed quickly on a downhole low-power microcontroller. At the same time, the compensation accuracy is guaranteed by the pre-calibrated compensation coefficients, which can accurately correct the first wave arrival time offset under the combined effect of temperature and eccentricity, thus achieving efficient and accurate delay compensation.

[0015] Optionally, in step S5, the evaluation criteria for signal value include signal-to-noise ratio, clarity of the first wave, magnitude of formation changes, and the presence of abnormal operating conditions.

[0016] By adopting the above technical solution, and by comprehensively considering the signal-to-noise ratio, clarity of the first wave, formation variation amplitude, and the presence of abnormal working conditions, the importance of different data can be accurately distinguished, providing a scientific and reliable basis for intelligent hierarchical storage. This evaluation system can ensure that data that is crucial to the evaluation of sonic logging is given priority protection and complete storage, while efficiently compressing conventional data, thus realizing the rational allocation and utilization of storage resources.

[0017] This application also provides a downhole acoustic signal adaptive enhancement and intelligent storage and transmission system, including a signal preprocessing module, a gain control module, a delay control module, a data compression module, and an intelligent storage module connected in sequence.

[0018] The gain control module is a closed-loop automatic gain control module, which is used to adjust the amplifier gain in real time according to the amplitude of the received signal so that the amplitude of the output signal is kept within a preset range.

[0019] The delay control module is a temperature-eccentric dual-factor coupled automatic delay control module, which is used to calculate and adjust the delay time of acoustic wave transmission and reception in real time based on the downhole temperature and instrument eccentricity.

[0020] The data compression module employs an adaptive data compression algorithm to compress the acquired full-wavelength acoustic data in real time.

[0021] The intelligent storage module adopts a dynamic hierarchical storage strategy based on signal value, which is used to classify, store and index compressed data according to data tags.

[0022] By adopting the above technical solutions, an integrated system architecture of "signal preprocessing - gain control - delay compensation - data compression - intelligent storage" was constructed. This is the first time that adaptive signal enhancement technology and intelligent data management technology have been organically combined, simultaneously solving the two core pain points of existing technologies: "unstable signal quality" and "high data storage and transmission pressure." Closed-loop automatic gain control stabilizes the signal amplitude, and dual-factor coupled delay control corrects the first wave arrival time, improving the signal-to-noise ratio and measurement accuracy of the acoustic signal from the source. Adaptive data compression and hierarchical storage based on signal value significantly reduce the data volume while ensuring no loss of key information, achieving an optimal balance between signal quality and data efficiency. This significantly improves the accuracy and reliability of acoustic logging evaluation and enables it to adapt to complex downhole environments with high temperature, high pressure, and strong interference.

[0023] Optionally, the closed-loop automatic gain control module includes a peak detection unit, a gain calculation unit, and an adjustable gain amplifier connected in sequence; the peak detection unit detects the peak amplitude of the received signal in real time, the gain calculation unit calculates the gain adjustment amount based on the difference between the preset target amplitude and the actual peak amplitude, and the adjustable gain amplifier adjusts the amplification factor in real time based on the gain adjustment amount.

[0024] By adopting the above technical solution and employing a closed-loop feedback structure of "peak detection - gain calculation - adjustable gain amplification," real-time dynamic adjustment of the signal amplitude is achieved. This structure can quickly respond to signal amplitude fluctuations caused by factors such as downhole formation changes and instrument eccentricity, stabilizing the output signal amplitude within the preset optimal range. This avoids measurement errors caused by signal oversaturation or insufficient amplitude, providing a stable and reliable input signal for subsequent signal processing and analysis, and effectively improving the system's anti-interference capability and measurement consistency.

[0025] Optionally, the temperature-eccentric dual-factor coupled automatic delay control module includes a temperature acquisition unit, an eccentricity calculation unit, and a delay compensation unit; the temperature acquisition unit acquires the downhole ambient temperature, the eccentricity calculation unit calculates the instrument eccentricity based on the time difference of the multi-channel acoustic signal processed by the signal preprocessing module, and the delay compensation unit calculates the delay compensation amount based on the coupling relationship between temperature and eccentricity, and updates the transmission and reception delay parameters.

[0026] By adopting the above technical solution, and by simultaneously acquiring downhole temperature data and calculating instrument eccentricity based on multi-channel acoustic time difference, two key factors affecting the first wave arrival time are coupled and calculated. This enables comprehensive and accurate correction of the first wave arrival time offset in complex downhole environments. In particular, it solves the problem of large measurement errors caused by instrument eccentricity in horizontal wells and highly deviated wells, reducing the measurement error of the first wave arrival time from more than 10μs in the existing technology to less than 1μs, and significantly improving the accuracy of acoustic logging evaluation.

[0027] Optionally, the adaptive data compression algorithm employs an adaptive quantization step size adjustment mechanism, which dynamically adjusts the quantization step size according to the local variation characteristics of the signal. Under the premise of ensuring that the waveform characteristics are not distorted, a smaller quantization step size is used for regions with drastic signal changes, and a larger quantization step size is used for regions with gentle signal changes.

[0028] By adopting the above technical solution and dynamically adjusting the quantization step size according to the local variation characteristics of the signal, the contradiction between "loss of details" and "low compression efficiency" in traditional fixed quantization step size compression algorithms is resolved. A smaller quantization step size is used in regions of drastic signal change to ensure the integrity of key waveform features such as the initial wave and reflected waves; a larger quantization step size is used in regions of gentle signal change to maximize the compression ratio. This mechanism can achieve a compression ratio of over 4:1 while ensuring the reconstructed signal signal-to-noise ratio is higher than 40dB and fully meeting the requirements for acoustic logging evaluation, significantly reducing data storage and transmission time.

[0029] Optionally, the dynamic hierarchical storage strategy based on signal value divides the data into three storage levels: the first level is key feature data, which is stored in an uncompressed manner; the second level is full-wavelength data under abnormal operating conditions, which is stored in a low compression ratio manner; and the third level is full-wavelength data under normal operating conditions, which is stored in a high compression ratio manner.

[0030] By adopting the above technical solution, differentiated storage methods and compression ratios are used based on the importance of the data to the evaluation of sonic logging. Uncompressed storage of key feature data ensures rapid access and high accuracy of core parameters; low-compression storage of full-wavelength data under abnormal operating conditions preserves complete waveform information for subsequent detailed analysis; and high-compression storage of full-wavelength data under normal operating conditions maximizes storage space savings. This strategy achieves optimal allocation of storage resources, resolving the contradiction between "insufficient storage space" and "loss of critical data" in traditional full-volume storage methods, and achieving the best balance between data integrity and storage efficiency within limited downhole storage capacity.

[0031] Optionally, the intelligent storage module has a built-in data tag index unit, which adds tags containing timestamps, depths, strip numbers, and signal quality levels to each set of collected data, and establishes a tag index table to support quick data retrieval based on tags.

[0032] By adopting the above technical solution, users can quickly retrieve and locate the required data based on any combination of tags such as timestamp, depth, strip number, and signal quality level, reducing data retrieval time from several hours to several seconds. This greatly improves the efficiency of on-site data processing and analysis, facilitates engineers in quickly locating problem well sections, and meets the needs of rapid on-site evaluation.

[0033] Optionally, the system further includes an on-demand acquisition control module connected to the intelligent storage module, used to selectively acquire acoustic wave data of a specific depth, specific strip, or specific mode according to instructions from the host computer.

[0034] By adopting the above technical solution, the system can selectively acquire acoustic data within a specific depth range, in a specific circumferential strip, or in a specific mode according to instructions from the host computer, avoiding unnecessary acquisition of all modes across the entire well section. This function can not only significantly shorten logging operation time and improve operational efficiency, but also reduce the generation of invalid data at the source, further alleviating the system's storage and transmission pressure. It is particularly suitable for scenarios involving intensive acquisition of key well sections and review of problematic well sections.

[0035] In summary, this application includes at least one of the following beneficial technical effects:

[0036] 1. This method executes in the logical sequence of signal enhancement, data compression, intelligent storage, and on-demand transmission. Each step can dynamically adjust parameters according to real-time downhole conditions, forming a complete closed-loop control system. The method has a clear process, low computational load, and is suitable for implementation in downhole embedded systems. It can significantly improve system operating efficiency and reliability while ensuring measurement accuracy.

[0037] 2. An adaptive data compression algorithm is adopted, which dynamically adjusts the quantization step size according to the local characteristics of the signal. While ensuring that key waveform features are not lost, a compression ratio of more than 4:1 is achieved, which greatly reduces the amount of data storage and transmission time.

[0038] 3. A dynamic hierarchical storage strategy based on signal value employs different compression ratios and storage methods for data of varying importance, ensuring the integrity of critical data while maximizing storage space savings; the data tag indexing mechanism enables rapid data retrieval and location.

[0039] 4. It supports selectively acquiring data at specific depths, in specific strips, or in specific modes based on instructions from the host computer, avoiding unnecessary acquisition of data across the entire well section and mode, further improving logging efficiency and shortening operation time. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of the overall architecture of the system described in this application.

[0041] Figure 2 This is an overall workflow diagram of the system described in this application.

[0042] Figure 3 This is the flowchart of the closed-loop automatic gain control described in this application. Detailed Implementation

[0043] To facilitate understanding of this application, a more detailed description is provided below with reference to the accompanying drawings and specific embodiments. It should be noted that when an element is described as "fixed to" another element, it can be directly on the other element, or one or more intermediate elements may exist between them. When an element is described as "connected to" another element, it can be directly connected to the other element, or one or more intermediate elements may exist between them. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this specification are for illustrative purposes only.

[0044] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the scope of this application. The term "and / or" as used in this specification includes any and all combinations of one or more of the associated listed items.

[0045] Reference Figures 1 to 3 This application discloses an adaptive enhancement and intelligent storage and transmission method for downhole acoustic signals, comprising the following steps:

[0046] S1 signal preprocessing: The acquired raw acoustic signal is filtered and denoised to remove power frequency interference, random noise and DC component.

[0047] S2 Adaptive Gain Control: The amplifier gain is adjusted in real time according to the signal amplitude to keep the output signal amplitude stable within the preset range; the peak detection unit detects the peak amplitude of the received signal in real time, the gain calculation unit calculates the gain adjustment amount based on the difference between the preset target amplitude and the actual peak amplitude, and the adjustable gain amplifier adjusts the amplification factor in real time according to the gain adjustment amount.

[0048] S3 dual-factor delay compensation: The hardware delay time of acoustic wave transmission and reception is calculated and adjusted in real time based on the downhole temperature and instrument eccentricity; the temperature acquisition unit collects the downhole ambient temperature, the eccentricity calculation unit calculates the instrument eccentricity based on the time difference of the multi-channel acoustic wave signals, and the delay compensation unit calculates the delay compensation amount based on the coupling relationship between temperature and eccentricity, and updates the transmission and reception delay parameters.

[0049] S4 Adaptive Data Compression: Adaptive data compression algorithm is used to compress the processed full-wavelength acoustic data in real time; the quantization step size is dynamically adjusted according to the local variation characteristics of the signal. Under the premise of ensuring that the waveform characteristics are not distorted, a smaller quantization step size is used for areas of drastic signal change and a larger quantization step size is used for areas of gentle signal change.

[0050] S5 Intelligent Hierarchical Storage: The compressed data is classified and stored according to the signal value, and data tags are added to create an index. The evaluation criteria for signal value include signal-to-noise ratio, first wave clarity, stratigraphic variation amplitude, and whether there are abnormal operating conditions. The data is stored in the corresponding storage level according to the evaluation results, and a tag containing timestamp, depth, strip number, and signal quality level is added to each group of data to create a tag index table.

[0051] S6 On-Demand Data Transmission: Selectively transmits specified data according to instructions from the host computer; when a transmission instruction is received from the host computer, the corresponding data is retrieved and transmitted according to the tag conditions in the instruction; otherwise, the next round of data collection continues.

[0052] After the system is powered on, the above steps are executed repeatedly until the logging is completed. When the system detects that the signal quality level is lower than the preset minimum threshold for three consecutive acquisition cycles, the system self-test program is automatically triggered, and a fault alarm signal is sent to the host computer. The complete signal processing flow realizes full automation from raw signal acquisition to enhancement, compression, storage, and transmission. It can adapt to the complex and ever-changing downhole environmental conditions and significantly improve data processing and transmission efficiency while ensuring measurement accuracy.

[0053] This application also discloses a downhole acoustic signal adaptive enhancement and intelligent storage and transmission system that implements the above-described method. For example... Figure 1 As shown, the system includes a signal preprocessing module, a gain control module, a delay control module, a data compression module, and an intelligent storage module connected in sequence, as well as an on-demand acquisition control module connected to the intelligent storage module. These modules are connected sequentially according to the signal processing flow, working together to complete the entire process of enhancing, compressing, storing, and transmitting the acoustic signal.

[0054] The signal preprocessing module performs preliminary processing on the acquired raw acoustic signal, removing power frequency interference, random noise, and DC components. The module integrates a 50Hz power frequency notch filter, an 8th-order Butterworth low-pass anti-aliasing filter, and a high-pass filter, effectively filtering out various interference signals in the downhole environment while retaining the valid acoustic signal components. The preprocessed signal is then output to the gain control module for amplitude adjustment.

[0055] The gain control module is a closed-loop automatic gain control module used to address the problem of large amplitude fluctuations in downhole signals. The module includes a peak detection unit, a gain calculation unit, and an adjustable gain amplifier connected in sequence. The peak detection unit samples the input signal at fixed time intervals of 10μs to detect the peak amplitude of the signal in real time. The gain calculation unit compares the detected peak amplitude with a preset target amplitude (2V in this embodiment) and calculates the difference. If the difference exceeds the allowable range (±0.2V in this embodiment), the corresponding gain adjustment is calculated according to a preset gain adjustment algorithm. The adjustable gain amplifier adjusts the amplification factor in real time according to the gain adjustment, ensuring that the amplitude of the output signal remains within the preset optimal range. This closed-loop control mechanism can quickly respond to changes in signal amplitude, effectively compensating for amplitude fluctuations caused by changes in formation characteristics or instrument eccentricity, thus ensuring the accuracy of subsequent signal processing.

[0056] The delay control module is a temperature-eccentric dual-factor coupled automatic delay control module, used to solve the first wave arrival time deviation problem caused by downhole temperature changes and instrument eccentricity. The module includes a temperature acquisition unit, an eccentricity calculation unit, and a delay compensation unit. The temperature acquisition unit uses a high-precision digital temperature sensor installed inside the instrument to acquire the downhole ambient temperature in real time, covering a measurement range of -40℃ to 185℃ with an accuracy of ±0.5℃. The eccentricity calculation unit calculates the instrument eccentricity based on the time difference of the multi-channel acoustic signals processed by the signal preprocessing module. By comparing the first wave arrival time differences of different circumferential strips, it accurately calculates the direction and degree of eccentricity of the instrument in the wellbore. The delay compensation unit calculates the delay compensation amount based on the coupling relationship between temperature and eccentricity, updating the transmit and receive delay parameters. The total delay compensation amount of the temperature-eccentric dual-factor coupled delay compensation is obtained by multiplying the delay change caused by temperature by the temperature compensation coefficient and adding it to the delay change caused by eccentricity multiplied by the eccentricity compensation coefficient. In this embodiment, the temperature compensation coefficient is 0.1 μs / ℃, and the eccentricity compensation coefficient is 0.5 μs / %. These compensation coefficients were obtained through indoor simulation experiments and on-site calibration. Based on the calculated delay compensation, the system updates the hardware delay time of sound wave transmission and reception in real time, ensuring that the receiving window is accurately aligned with the arrival time of the first wave. This avoids the problem of missed or incorrect first wave sampling, significantly improving the measurement accuracy of the first wave arrival time.

[0057] The data compression module employs an adaptive data compression algorithm for real-time compression of the acquired full-wavelength acoustic data. This algorithm utilizes an adaptive quantization step size adjustment mechanism, dynamically adjusting the quantization step size based on the local variation characteristics of the signal. While ensuring no distortion of waveform features, a smaller quantization step size is used for regions of rapid signal change, and a larger quantization step size is used for regions of gradual signal change. The algorithm first performs differential operations on the input signal to obtain the signal variation. Then, based on the local variation characteristics of the signal, it dynamically adjusts the quantization step size: a smaller quantization step size is used when the signal changes rapidly to ensure no loss of waveform details; a larger quantization step size is used when the signal changes gradually to improve the compression ratio. This adaptive adjustment mechanism achieves higher compression efficiency while preserving key waveform characteristics. In this embodiment, the improved ADPCM algorithm achieves a compression ratio of over 4:1 for the acoustic signal, and the signal-to-noise ratio of the reconstructed signal is higher than 40dB, fully meeting the accuracy requirements for acoustic logging evaluation.

[0058] The intelligent storage module employs a dynamic hierarchical storage strategy based on signal value, used to classify, store, and index compressed data according to data tags. This strategy divides data into three storage levels: the first level contains key feature data, stored uncompressed; the second level contains full-wavelength data under abnormal operating conditions, stored with a low compression ratio; and the third level contains full-wavelength data under normal operating conditions, stored with a high compression ratio. The first-level key feature data includes arrival time of the first wave, amplitude, dominant frequency, and attenuation coefficient. These data are small in volume but of the highest value, and are stored uncompressed to ensure fast access and high accuracy. The second-level abnormal operating condition full-wavelength data, when the signal-to-noise ratio is detected to be below 20dB, the formation variation exceeds 30%, or the instrument eccentricity is greater than 20%, is stored with a low compression ratio of 2:1, preserving complete waveform information for subsequent detailed analysis. The third-level normal operating condition full-wavelength data, for full-wavelength data under normal operating conditions, is stored with a high compression ratio of 4:1 or higher, maximizing storage space savings. The intelligent storage module has a built-in data tag index unit that adds tags containing timestamps, depths, stripe numbers, and signal quality levels to each set of collected data, creating a tag index table that supports quick data retrieval based on tags. Signal value is calculated using a weighted quantization method, with the formula: Signal Value = 0.4 × Normalized Signal-to-Noise Ratio + 0.3 × Normalized First Wave Sharpness + 0.2 × Normalized Formation Variation Amplitude + 0.1 × Abnormal Operating Condition Coefficient, where the abnormal operating condition coefficient is 1 when abnormal conditions exist and 0 when normal conditions exist. Users can quickly retrieve the required data based on any combination of tags, greatly improving the efficiency of data management and analysis.

[0059] The on-demand acquisition control module connects to the intelligent storage module to selectively acquire acoustic data at specific depths, in specific bands, or in specific modes based on instructions from the host computer. The module can receive instructions from the host computer and selectively acquire acoustic data within a specific depth range, in a specific circumferential band, or in a specific mode, without needing to acquire data across the entire well section and all modes. For example, when a field engineer finds doubtful logging results at a certain depth, they can send instructions through the host computer to control the instrument to perform intensive or full-wavelength acquisition at that depth; for other depths, only key feature data is acquired. This on-demand acquisition mechanism can significantly shorten logging time, improve operational efficiency, and further reduce unnecessary data storage and transmission.

[0060] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A method for adaptive enhancement and intelligent storage and transmission of downhole acoustic signals, characterized in that: Includes the following steps: S1 signal preprocessing: Filtering and denoising the acquired raw acoustic signal; S2 Adaptive Gain Control: Adjusts the amplifier gain in real time according to the signal amplitude to keep the output signal amplitude stable within the preset range; S3 dual-factor delay compensation: calculates and adjusts the hardware delay time of acoustic wave transmission and reception in real time based on downhole temperature and instrument eccentricity; S4 Adaptive Data Compression: The adaptive data compression algorithm is used to compress the processed full-wavelength acoustic data in real time. The adaptive data compression algorithm adopts an adaptive quantization step size adjustment mechanism, which dynamically adjusts the quantization step size according to the local change characteristics of the signal. Under the premise of ensuring that the waveform characteristics are not distorted, a smaller quantization step size is used for regions with drastic signal changes, and a larger quantization step size is used for regions with gentle signal changes. S5 Intelligent Hierarchical Storage: The compressed data is classified and stored according to the signal value, and data tags are added to create an index; S6 On-Demand Data Transmission: Selectively transmits specified data according to instructions from the host computer.

2. The method for adaptive enhancement and intelligent storage and transmission of downhole acoustic signals according to claim 1, characterized in that: In step S3, the total delay compensation amount of the temperature-eccentric dual-factor coupled delay compensation is obtained by multiplying the delay change caused by temperature by the temperature compensation coefficient and adding the delay change caused by eccentricity by the eccentricity compensation coefficient.

3. The method for adaptive enhancement and intelligent storage and transmission of downhole acoustic signals according to claim 1, characterized in that: In step S5, the evaluation criteria for signal value include signal-to-noise ratio, clarity of the first wave, stratigraphic variation, and the presence of abnormal operating conditions.

4. A downhole acoustic signal adaptive enhancement and intelligent storage and transmission system for implementing the method of any one of claims 1-3, characterized in that: It includes a signal preprocessing module, a gain control module, a delay control module, a data compression module, and an intelligent storage module connected in sequence; The gain control module is a closed-loop automatic gain control module, which is used to adjust the amplifier gain in real time according to the amplitude of the received signal so that the amplitude of the output signal is kept within a preset range. The delay control module is a temperature-eccentric dual-factor coupled automatic delay control module, which is used to calculate and adjust the delay time of acoustic wave transmission and reception in real time based on the downhole temperature and instrument eccentricity. The data compression module employs an adaptive data compression algorithm to compress the acquired full-wavelength acoustic data in real time. The intelligent storage module adopts a dynamic hierarchical storage strategy based on signal value, which is used to classify, store and index compressed data according to data tags.

5. The downhole acoustic signal adaptive enhancement and intelligent storage and transmission system according to claim 4, characterized in that: The closed-loop automatic gain control module includes a peak detection unit, a gain calculation unit, and an adjustable gain amplifier connected in sequence. The peak detection unit detects the peak amplitude of the received signal in real time, the gain calculation unit calculates the gain adjustment amount based on the difference between the preset target amplitude and the actual peak amplitude, and the adjustable gain amplifier adjusts the amplification factor in real time based on the gain adjustment amount.

6. The downhole acoustic signal adaptive enhancement and intelligent storage and transmission system according to claim 4, characterized in that: The temperature-eccentricity dual-factor coupled automatic delay control module includes a temperature acquisition unit, an eccentricity calculation unit, and a delay compensation unit. The temperature acquisition unit acquires the downhole ambient temperature, the eccentricity calculation unit calculates the instrument eccentricity based on the time difference of the multi-channel acoustic signal processed by the signal preprocessing module, and the delay compensation unit calculates the delay compensation amount based on the coupling relationship between temperature and eccentricity, and updates the transmission and reception delay parameters.

7. The downhole acoustic signal adaptive enhancement and intelligent storage and transmission system according to claim 4, characterized in that: The dynamic hierarchical storage strategy based on signal value divides the data into three storage levels: the first level is key feature data, which is stored in an uncompressed manner; the second level is full-wavelength data under abnormal operating conditions, which is stored in a low compression ratio manner; and the third level is full-wavelength data under normal operating conditions, which is stored in a high compression ratio manner.

8. The downhole acoustic signal adaptive enhancement and intelligent storage and transmission system according to claim 4, characterized in that: The intelligent storage module has a built-in data tag index unit, which adds tags containing timestamps, depths, strip numbers, and signal quality levels to each set of collected data, and establishes a tag index table to support quick data retrieval based on tags.

9. The downhole acoustic signal adaptive enhancement and intelligent storage and transmission system according to claim 4, characterized in that: The system also includes an on-demand acquisition control module connected to the intelligent storage module, used to selectively acquire acoustic wave data of a specific depth, specific strip, or specific mode according to instructions from the host computer.

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