Acoustic logging saturation waveform recovery method and device and electronic equipment

Abstract

The invention relates to the field of geophysical logging, and discloses an acoustic logging saturation waveform recovery method and device and electronic equipment. The method comprises the following steps: marking a saturation position in an initial time domain saturation waveform as 1 through a preset saturation position marking function, and marking an unsaturated position in the initial time domain saturation waveform as 0; performing linear integral transformation processing on the initial time domain saturation waveform; preprocessing the linear integral transformation data and performing inverse transformation on the whole preprocessed data; traversing the time domain waveform after inverse transformation, and setting the amplitude value of the current time point as a saturation value when related conditions are met; otherwise, inserting the initial value at the position corresponding to the initial time domain saturation waveform; and gradually reducing the given decreasing proportionality coefficient and repeating the steps until the result tends to be stable or the number of times of repetition is greater than a preset threshold value. The defects that the collected logging information is abandoned due to the fact that the waveform is saturated and the collected logging information is unqualified, and local well section collection of the acoustic logging information is carried out again are overcome.

Description

Technical Field

[0001] The present application relates to the technical field of geophysical logging, and particularly to a method, device, storage medium, and electronic device for restoring saturated waveforms in acoustic logging. Background Art

[0002] The purpose of the background art provided here is to generally give the background of the present application. The statements in this part only provide the background related to the present application and do not necessarily constitute the prior art.

[0003] Acoustic logging is an important type of geophysical logging method, which can evaluate formation porosity, permeability, and rock mechanical properties. According to the different acoustic information used, acoustic logging methods can be divided into acoustic velocity logging, acoustic amplitude logging, and ultrasonic imaging logging.

[0004] Among them, acoustic velocity logging obtains the first arrival of the longitudinal wave by using threshold detection and calculates the longitudinal wave slowness (the reciprocal of velocity). In addition, by means of the time-slowness correlation algorithm, a specific time window is selected for each receiver channel, and the similarity metric parameter of the waveform within the window is calculated to generate a two-dimensional time-slowness spectrum. The arrival time and slowness of the longitudinal wave, transverse wave, and Stoneley wave can be picked up on the spectrum diagram, which is used for the evaluation of formation elastic mechanical properties and permeability.

[0005] Acoustic amplitude logging is usually applied to the evaluation of cementing quality in cased wells, and methods such as cement bond logging and variable density acoustic logging have been developed. Cement bond logging records the amplitude of the first arrival, and variable density acoustic logging records the wave train within a specific time window and displays the positive or negative half cycle of the waveform in gray scale. Both logging methods can evaluate the cementing condition of the interfaces between the casing, formation, and cement sheath.

[0006] Usually, due to improper gain setting, the acoustic logging waveform becomes saturated, and the above-mentioned data needs to be re-measured for part or even all of the well sections because of its incompleteness, which prolongs the well occupation time. Summary of the Invention

[0007] In view of the above problems, the present application proposes a method, device, storage medium, and electronic device for restoring saturated waveforms in acoustic logging. The original waveform can be restored from the above-mentioned discarded data, so that it meets the logging data acquisition standard and becomes qualified data. The waveform signal collected by the acoustic logging instrument is a band-limited signal, and the frequencies of the saturated signal and the unsaturated signal are close. If part of the uniformly sampled signal is missing, spectral leakage will occur, specifically manifested as the amplitude of some spectral peaks on the spectrum being lower than that of the complete signal, and the missing energy will be superimposed at the wrong frequencies. By repositioning the energy with frequency leakage on the spectrum, the complete signal can be restored.

[0008] In the first aspect of the present application, a method for restoring saturated waveforms in acoustic logging is provided, and the method includes:

[0009] Mark the saturation positions in the initial time-domain saturation waveform as a first preset value through a preset saturation position marking function, and mark the non-saturation positions in the initial time-domain saturation waveform as a second preset value;

[0010] Perform a linear integral transform process on the initial time-domain saturation waveform to obtain linear integral transform data;

[0011] Preprocess the linear integral transform data and perform an inverse transform on the preprocessed data to obtain the inverse-transformed time-domain waveform;

[0012] Traverse all time points in the inverse-transformed time-domain waveform. Under the condition that the amplitude value of the current time point is not greater than the saturation value and at the position marked as the first preset value by the preset saturation position marking function, set the amplitude value of the current time point to the saturation value; otherwise, insert the initial value at the corresponding position of the initial time-domain saturation waveform. After the traversal is completed, obtain the processed time-domain waveform;

[0013] When the current given decreasing ratio coefficient is not less than the preset termination ratio coefficient or the current loop count is less than the preset loop count, gradually decrease the given decreasing ratio coefficient and use the processed time-domain waveform as the time-domain saturation waveform to be linearly integral-transformed, and jump to the linear integral transform processing step until the current given decreasing ratio coefficient is less than the preset termination ratio coefficient or the current loop count is not less than the preset loop count, and obtain the restored and unsaturated complete waveform.

[0014] Further, the obtaining method of the initial time-domain saturation waveform includes:

[0015] Traverse the waveform data collected by acoustic logging, mark the single-channel data with local saturation waveforms, and open a time window locally for the entire segment of the single-channel waveform, and extract the local waveform data containing several cycles of saturated and non-saturated waveforms at the same time to obtain the initial time-domain saturation waveform.

[0016] Further, the linear integral transform includes a time-domain fast Fourier transform;

[0017] The inverse transform includes an inverse time-domain fast Fourier transform.

[0018] Further, the initial time-domain saturation waveform includes:

[0019] The waveform data received by an acoustic logging instrument with a monopole transmitter, a dipole transmitter, or a quadrupole transmitter.

[0020] Further, the initial time-domain saturation waveform includes:

[0021] Waveform data received by a digital acoustic logging device, an array acoustic logging device, or a cross-dipole acoustic logging device.

[0022] Further, the preprocessing of the saturated waveform after the linear integral transformation and the inverse transformation of the preprocessed data include:

[0023] Setting the values of the part of the linear integral transformation data that is not greater than a given decreasing threshold to 0 and keeping the other values unchanged to obtain preprocessed data;

[0024] Performing an inverse transformation on the preprocessed data.

[0025] In a second aspect of the present application, an acoustic logging saturated waveform recovery device is provided, and the device includes:

[0026] A first processing module for marking the saturated positions in the initial time-domain saturated waveform as a first preset value and marking the unsaturated positions in the initial time-domain saturated waveform as a second preset value through a preset saturated position marking function;

[0027] A linear integral transformation module for performing a linear integral transformation process on the initial time-domain saturated waveform to obtain linear integral transformation data;

[0028] An inverse transformation module for preprocessing the linear integral transformation data and performing an inverse transformation on the preprocessed data to obtain an inverse-transformed time-domain waveform;

[0029] A traversal module for traversing all time points in the inverse-transformed time-domain waveform, and setting the amplitude value of the current time point to the saturation value under the condition that the amplitude value of the current time point is not greater than the saturation value and at the position marked as the first preset value by the preset saturated position marking function; otherwise, inserting the initial value at the corresponding position of the initial time-domain saturated waveform, and obtaining a processed time-domain waveform after the traversal is completed;

[0030] A second processing module for gradually decreasing the given decreasing ratio coefficient and using the processed time-domain waveform as the time-domain saturated waveform to be linearly integral-transformed and jumping to the linear integral transformation processing step until the current given decreasing ratio coefficient is less than the preset termination ratio coefficient or the current number of loops is not less than the preset number of loops, and obtaining a restored and unsaturated complete waveform when the current given decreasing ratio coefficient is less than the preset termination ratio coefficient or the current number of loops is not less than the preset number of loops.

[0031] In a third aspect of the present application, a computer-readable storage medium is provided, and a computer program stored in the computer-readable storage medium can be executed by one or more processors to implement the steps of the method as described above.

[0032] In a fourth aspect of the present application, there is provided an electronic device, including a memory and one or more processors. A computer program is stored on the memory, and the memory and the one or more processors are communicatively connected to each other. When the computer program is executed by the one or more processors, the steps of the method described above are implemented.

[0033] Compared with the prior art, the advantages or beneficial effects of the technical solution of the present application include:

[0034] It can solve the defect that due to the excessive acquisition gain setting of the acoustic logging instrument during the logging process, the waveform is saturated, and then the acquired logging data is discarded due to unqualified, and it is necessary to re-acquire the local well section of the acoustic logging data. The present application can restore the complete signal by re-aligning the energy with frequency leakage on the spectrum. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained according to the provided drawings.

[0036] In addition, it should be noted that for the convenience of description, only the parts related to the present disclosure are shown in the drawings. The specification drawings constituting a part of the present application are used to provide a further understanding of the present application. The schematic embodiments and descriptions in the present application are used to explain the present application and do not constitute an improper limitation to the present application. In the drawings:

[0037] Figure 1 is a flowchart of a method for restoring a saturated waveform of acoustic logging provided by an embodiment of the present application;

[0038] Figure 2 is a full-wave waveform curve obtained from a typical acoustic logging provided by an embodiment of the present application;

[0039] Figure 3 is a flowchart of another method for restoring a saturated waveform of acoustic logging provided by an embodiment of the present application;

[0040] Figure 4 is a schematic diagram of a saturation signal and time window provided by an embodiment of the present application;

[0041] Figure 5 is a waveform curve of dipole shear wave logging before and after saturation and restoration provided by an embodiment of the present application;

[0042] Figure 6A monopole longitudinal wave logging waveform curve after saturation and recovery provided by an embodiment of the present application. Detailed implementation manners

[0043] The following will combine the accompanying drawings and embodiments to elaborate on the implementation manners of the present application, so as to fully understand how the present application uses technical means to solve technical problems and the implementation process of achieving corresponding technical effects and implement accordingly. Each feature in the embodiments of the present application can be combined with each other on the premise of not conflicting, and the formed technical solutions are all within the protection scope of the present application.

[0044] It should be clear that the following described embodiments are only a part of the embodiments of the present application, rather than all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments in the present application without creative efforts belong to the protection scope of the present application.

[0045] The technical solution of the present application aims to solve the problem that the waveform is saturated due to excessive gain setting, and recover it to avoid re-measurement.

[0046] The present application provides a method for recovering a saturated waveform of acoustic logging. Figure 1 A flowchart of a method for recovering a saturated waveform of acoustic logging provided by an embodiment of the present application.

[0047] Further, reference can be made to Figures 2 to 6 , where Figure 2 A full-wave waveform curve obtained by a typical acoustic logging provided by an embodiment of the present application; Figure 3 A flowchart of saturated waveform recovery provided by an embodiment of the present application; Figure 4 A schematic diagram of a saturation signal and a time window provided by an embodiment of the present application; Figure 5 A dipole shear wave logging waveform curve after saturation and recovery provided by an embodiment of the present application; Figure 6 A monopole longitudinal wave logging waveform curve after saturation and recovery provided by an embodiment of the present application.

[0048] As Figure 1 shown, the method for recovering a saturated waveform of acoustic logging disclosed in the present application includes the following steps:

[0049] Step 110: Mark the saturated positions in the initial time-domain saturated waveform as a first preset value through a preset saturation position marking function, and mark the unsaturated positions in the initial time-domain saturated waveform as a second preset value.

[0050] In some embodiments, the acquisition method of the initial time-domain saturated waveform includes:

[0051] Traverse the waveform data collected by acoustic logging, mark the single-channel data with locally saturated waveforms, and open a time window locally for the entire single-channel waveform to extract the local waveform data that contains saturated and unsaturated waveforms of several cycles at the same time, so as to obtain the initial time-domain saturated waveform.

[0052] In some embodiments, the initial time-domain saturated waveform includes:

[0053] The waveform data received by an acoustic logging instrument with a monopole transmitter transducer, a dipole transmitter transducer or a quadrupole transmitter transducer.

[0054] In some embodiments, the initial time-domain saturated waveform includes:

[0055] The waveform data received by a digital acoustic logging device, an array acoustic logging device or a cross-dipole acoustic logging device.

[0056] Optionally, traverse the waveform data collected by acoustic logging, mark the single-channel data with locally saturated waveforms; and open a time window locally for the entire single-channel waveform to extract the local waveform data that contains saturated and unsaturated waveforms of several cycles at the same time.

[0057] It should be noted that the method disclosed in this application can be used for processing the waveform data received by monopole, dipole, and quadrupole acoustic logging; it can also be used for processing the waveform data received by acoustic logging devices such as digital acoustic, array acoustic, and cross-dipole.

[0058] Optionally, the first preset value can be 1 and the second preset value can be 0.

[0059] Further, mark the saturated position as 1 and the unsaturated position as 0 through a preset saturation position marking function. Among them, the saturated position is the maximum and minimum values of the signal amplitude for AD conversion.

[0060] Step 120: Perform a linear integral transform process on the initial time-domain saturated waveform to obtain linear integral transform data.

[0061] In some embodiments, the linear integral transform includes a time-domain fast Fourier transform.

[0062] Optionally, perform a Fourier transform on the local waveform data of acoustic logging containing saturated signals.

[0063] Step 130: Preprocess the linear integral transform data and perform an inverse transform on the preprocessed data to obtain the time-domain waveform after the inverse transform.

[0064] In some embodiments, the inverse transform includes an inverse time-domain fast Fourier transform.

[0065] In some embodiments, preprocessing the saturated waveform after the linear integral transformation and performing an inverse transformation on the preprocessed data includes:

[0066] Setting the values of the part of the linear integral transformation data that is not greater than a given decreasing threshold to 0, and keeping the other values unchanged, to obtain preprocessed data;

[0067] Performing an inverse transformation on the preprocessed data.

[0068] Optionally, setting the values of the part of the linear integral transformation data that is not greater than a given decreasing threshold to 0, keeping the other values unchanged, to obtain preprocessed data, and performing an inverse transformation on the whole preprocessed data to obtain the time-domain waveform after the inverse transformation.

[0069] Step 140: Traverse all time points in the time-domain waveform after the inverse transformation. Under the condition that the amplitude value of the current time point is not greater than the saturation value and is marked as the first preset value by the preset saturation position marking function, set the amplitude value of the current time point to the saturation value; otherwise, insert the initial value at the corresponding position of the initial time-domain saturation waveform. After the traversal is completed, obtain the processed time-domain waveform.

[0070] Optionally, for the currently processed data, re-insert the unsaturated amplitude values in the time domain and assign the amplitude values at the saturation positions that are lower than the saturation value level to the saturation value.

[0071] Step 150: When the current given decreasing ratio coefficient is not less than the preset termination ratio coefficient or the current number of loops is less than the preset number of loops, gradually decrease the given decreasing ratio coefficient and use the processed time-domain waveform as the time-domain saturation waveform to be linearly integrally transformed, and jump to the linear integral transformation processing step until the current given decreasing ratio coefficient is less than the preset termination ratio coefficient or the current number of loops is not less than the preset number of loops, to obtain the restored and unsaturated complete waveform.

[0072] It can be understood that in step 150, increment the current number of loops by 1 and use the processed time-domain waveform as the time-domain saturation waveform to be linearly integrally transformed, then jump to the linear integral transformation processing step (i.e., step 120). Then, when performing the linear integral transformation, perform a linear integral transformation on this processed time-domain waveform again; then continue with the subsequent processing steps (steps 130 to 150).

[0073] As an example, the ratio of the amplitude of the saturated waveform that can be restored by this method to the amplitude of the original signal is not less than 0.4, the maximum number of iterations (i.e., the preset number of loops, where the preset number of loops can be set according to actual requirements) is about 400, and it can be taken as 350 - 450, and the preset termination ratio coefficient is not higher than 0.05.

[0074] Further, gradually decrease the saturation value and repeat the above steps until the result tends to be stable. The saturated waveform data collected due to improper gain setting in the prior art will be discarded as unqualified and re-measured. However, the method provided by this application can restore the above discarded data to the original waveform, so that it meets the logging data acquisition standard and becomes qualified data. The waveform signal collected by the acoustic logging instrument is a band-limited signal, and the frequencies of the saturated signal and the unsaturated signal are close. If some parts of the uniformly sampled signal are missing, spectral leakage will occur, specifically manifested as the amplitudes of some spectral peaks in the spectrum being lower than those of the complete signal, and the missing energy will be superimposed at the wrong frequencies. By repositioning the energy with frequency leakage in the spectrum, the complete signal can be restored. And for the acoustic logging waveform data where the ratio of the saturated waveform amplitude to the maximum amplitude of the original signal is not less than 0.4, that is, max(|w s (t)|)≥0.4*max(|w o (t)|), the restoration effect is good, where w s (t) is the saturated time-domain waveform, and w o (t) is the original time-domain waveform.

[0075] Further, this application further explains and illustrates the acoustic logging saturated waveform restoration method disclosed by this application by way of examples.

[0076] The acoustic variable density and array acoustic wave use a monopole transmitting transducer to transmit acoustic signals in the wellbore, and one or more receiving transducers arranged in the well receive the above acoustic signals and record the full-wave train signals for a certain period of time. Among them, the full-wave train received in the hard formation (formation sound velocity is greater than the well fluid sound velocity) includes: longitudinal wave, transverse wave and Stoneley wave, and the full-wave train received in the soft formation (formation sound velocity is less than the well fluid sound velocity) includes: longitudinal wave and Stoneley wave.

[0077] Generally, the amplitudes of the transverse wave and Stoneley wave are much larger than those of the longitudinal wave. During the acquisition process, due to improper receiving gain setting, the transverse wave and Stoneley wave will be saturated.

[0078] As an example, the acoustic variable density logging and array acoustic logging use the following steps to restore the saturated waveform for the single-channel or multi-channel acoustic signals received:

[0079] Step 1: Traverse the waveform data collected by the acoustic logging, and mark the single-channel data with local saturated waveforms.

[0080] Step 2: Open a time window locally for the single-channel whole waveform, and extract the local waveform data w(t) containing several periods of saturation and non-saturation.

[0081] Step 3: Mark the saturated positions as 1 and the unsaturated positions as 0 through the preset saturation position marking function f(t). Here, the saturated positions are where the signal amplitude is the maximum and minimum values of the AD conversion.

[0082] Step 4: Perform Fourier transform on the acoustic logging signal containing saturated signals.

[0083] Step 5: Set the values of the data obtained after Fourier transform that are not greater than a given decreasing threshold to 0, and keep the other values unchanged to obtain the preprocessed data, and perform an inverse transform on the entire preprocessed data to obtain the time-domain waveform after inverse transform.

[0084] Optionally, if |W(ω)| < α i max[|W(ω)|], then W(ω) = 0, where W(ω) = fft(w(t)).

[0085] where α i max[|W(ω)|] is the given decreasing threshold, and α i is the given decreasing proportionality coefficient.

[0086] Step 6: Re-insert the unsaturated amplitude values in the time domain and assign the amplitude values at the saturated positions that are lower than the saturation value level to the saturation value.

[0087] Step 7: Gradually decrease the threshold and repeat the above steps until the result tends to be stable.

[0088] Optionally, when i < I max or α i ≥ E max , let i = i + 1 and repeat steps 4 to 6, otherwise execute step 8 to output the restored waveform w(t); α i represents the proportionality coefficient of the frequency-domain amplitude threshold in the i-th iteration to the maximum amplitude max[|W(ω)|], and α i = ae b(i-1) , where a and b are constants, a = α 1 , the number of iterations I max can generally be set to 400 - 500, b is negative, and its value is determined by the proportionality coefficient of the frequency-domain amplitude threshold of the maximum number of iterations to the maximum amplitude max[|W(ω)|]. This proportionality coefficient is usually not higher than 0.05. Preferably, b can be selected as a value around -0.01, and E max is the preset termination proportionality coefficient.

[0089] Step 8: Replace the saturated waveform within the time window with the restored waveform.

[0090] Furthermore, the present application further explains and illustrates the acoustic logging saturation waveform recovery method disclosed in the present application by way of example.

[0091] An acoustic wave signal is transmitted in the wellbore by using a dipole emission transducer, and the received acoustic wave signal is received by a receiving transducer arranged in the well. In this case, the received acoustic wave signal includes waveforms such as direct longitudinal waves and reflected waves. The amplitude of the direct wave is much higher than that of the reflected wave. If the gain is not properly selected, the direct wave and even subsequent formation reflected waves may be saturated.

[0092] As an example, if the amplitude information of the above waveform is to be used, the following steps can be taken to recover it.

[0093] Step 1: Traverse the waveform data collected by acoustic logging and mark the single-channel data with locally saturated waveforms.

[0094] Step 2: Open a time window locally in the entire segment of the single-channel waveform, and extract local waveform data w(t) including several saturated and unsaturated cycles.

[0095] Step 3: Mark f(t) as 1 at the saturated position and 0 at the unsaturated position. Among them, the saturated position is the maximum and minimum values of the signal amplitude for AD conversion.

[0096] Step 4: Perform Fourier transform on the acoustic logging signal containing the saturated signal.

[0097] Step 5: Set the values of the data obtained after Fourier transform that are not greater than a given decreasing threshold to 0, and keep the other values unchanged to obtain the preprocessed data, and perform an inverse transform on the entire preprocessed data to obtain the time-domain waveform after inverse transform.

[0098] Step 6: Re-insert the unsaturated amplitude values in the time domain and assign the amplitude values at the saturated positions that are lower than the saturated value level to the saturated value.

[0099] For example, traverse all time points in the time-domain waveform after inverse transform. Under the condition that the amplitude value of the current time point is not greater than the saturated value and is marked as the first preset value by the preset saturated position marking function, set the amplitude value of the current time point to the saturated value; otherwise, insert the initial value at the corresponding position of the initial time-domain saturated waveform. After traversal, obtain the processed time-domain waveform.

[0100] Step 7: Gradually decrease the threshold and repeat the above steps until the result tends to be stable.

[0101] For example, when the currently given decreasing ratio coefficient is not less than the preset termination ratio coefficient or the current number of cycles is less than the preset number of cycles, gradually decrease the given decreasing ratio coefficient, use the processed time-domain waveform as the time-domain saturated waveform to be linearly integrated, and jump to the linear integration processing step until the currently given decreasing ratio coefficient is less than the preset termination ratio coefficient or the current number of cycles is not less than the preset number of cycles, so as to obtain the restored and unsaturated complete waveform.

[0102] Step Eight: Replace the saturated waveform within the time window with the restored waveform.

[0103] This application also provides an acoustic logging saturated waveform restoration device. This acoustic logging saturated waveform restoration device can be used to execute all or part of the steps of the acoustic logging saturated waveform restoration method of this application. For the details not disclosed in this device, please refer to the steps of the acoustic logging saturated waveform restoration method disclosed in this application. This acoustic logging saturated waveform restoration device includes:

[0104] The first processing module is used to mark the saturated positions in the initial time-domain saturated waveform as the first preset value and the unsaturated positions in the initial time-domain saturated waveform as the second preset value through a preset saturation position marking function;

[0105] The linear integral transformation module is used to perform linear integral transformation processing on the initial time-domain saturated waveform to obtain linear integral transformation data;

[0106] The inverse transformation module is used to preprocess the linear integral transformation data and perform inverse transformation on the preprocessed data to obtain the time-domain waveform after inverse transformation; among them, the inverse transformation module includes a preprocessing unit and an inverse transformation unit; the preprocessing unit is used to preprocess the linear integral transformation data, and the inverse transformation unit is used to perform inverse transformation on the preprocessed data to obtain the time-domain waveform after inverse transformation;

[0107] The traversal module is used to traverse all time points in the time-domain waveform after inverse transformation. When the amplitude value of the current time point is not greater than the saturation value and the current time point is marked as the first preset value by the preset saturation position marking function, set the amplitude value of the current time point to the saturation value; otherwise, insert the initial value at the corresponding position of the initial time-domain saturated waveform. After the traversal is completed, the processed time-domain waveform is obtained;

[0108] A second processing module, configured to gradually decrease the given decreasing ratio coefficient and use the processed time-domain waveform as the time-domain saturated waveform to be linearly integral-transformed and jump to the linear integral transformation processing step when the current given decreasing ratio coefficient is not less than the preset termination ratio coefficient or the current number of cycles is less than the preset number of cycles, until the current given decreasing ratio coefficient is less than the preset termination ratio coefficient or the current number of cycles is not less than the preset number of cycles, so as to obtain the restored and unsaturated complete waveform.

[0109] In some embodiments, the obtaining manner of the initial time-domain saturated waveform includes:

[0110] Traverse the waveform data collected by acoustic logging, mark the single-channel data with local saturated waveforms, open a time window locally for the entire segment of the single-channel waveform, and extract the local waveform data containing several cycles of saturated and unsaturated waveforms simultaneously to obtain the initial time-domain saturated waveform.

[0111] In some embodiments, the linear integral transformation includes fast Fourier transform in the time domain;

[0112] The inverse transformation includes inverse fast Fourier transform in the time domain.

[0113] In some embodiments, the initial time-domain saturated waveform includes:

[0114] Waveform data received by an acoustic logging instrument with a monopole transmitting transducer, a dipole transmitting transducer, or a quadrupole transmitting transducer.

[0115] In some embodiments, the initial time-domain saturated waveform includes:

[0116] Waveform data received by a digital acoustic logging device, an array acoustic logging device, or a cross-dipole acoustic logging device.

[0117] In some embodiments, the preprocessing of the saturated waveform after the linear integral transformation and the inverse transformation of the preprocessed data include:

[0118] Set the values of the part not greater than the given decreasing threshold in the linear integral transformation data to 0, and keep the other values unchanged to obtain the preprocessed data;

[0119] Perform an inverse transformation on the preprocessed data. For example, set the values of the part not greater than the given decreasing threshold in the linear integral transformation data to 0, keep the other values unchanged to obtain the preprocessed data, and perform an inverse transformation on the whole of the preprocessed data, thereby obtaining the time-domain waveform after the inverse transformation.

[0120] Those skilled in the art should understand that the various modules or steps of the present application described above can be implemented by a general-purpose computing device. They can be concentrated on a single computing device or distributed over a network composed of multiple computing devices. Optionally, they can be implemented by program code executable by the computing device, so that they can be stored in a storage device and executed by the computing device. And in some cases, the steps shown or described can be executed in a different order than here, or they can be separately fabricated into individual integrated circuit modules, or multiple modules or steps among them can be fabricated into a single integrated circuit module for implementation.

[0121] Those skilled in the art can clearly understand that for the convenience and brevity of description, the specific working processes of the various modules in the acoustic logging saturation waveform recovery device can refer to the corresponding processes in the foregoing acoustic logging saturation waveform recovery method, and will not be repeated here.

[0122] The present application also provides a computer-readable storage medium. A computer program is stored in the computer-readable storage medium, and when the computer program is executed by a processor, all or part of the steps of the foregoing acoustic logging saturation waveform recovery method can be implemented, and will not be repeated here.

[0123] Among them, the computer-readable storage medium may also separately include a computer program, a data file, a data structure, etc., or include a combination thereof. The computer-readable storage medium or the computer program can be specifically designed and understood by those skilled in the computer software field, or the computer-readable storage medium may be well-known and available to those skilled in the computer software field. Examples of computer-readable storage media include: magnetic media, such as hard disks, floppy disks, and magnetic tapes; optical media, such as CD-ROM discs and DVDs; magneto-optical media, such as optical discs; and hardware devices specifically configured to store and execute computer programs, such as read-only memory (ROM), random access memory (RAM), flash memory; or servers, app application stores, etc. Examples of computer programs include machine code (e.g., code generated by a compiler) and files containing high-level code that can be executed by a computer by using an interpreter. The described hardware devices can be configured to act as one or more software modules to perform the operations and methods described above, and vice versa. In addition, the computer-readable storage medium can be distributed in a networked computer system and can store and execute program code or computer programs in a distributed manner.

[0124] The present application also provides a computer program product. The computer program product includes a computer program or instruction, and when the computer program or instruction is executed by a processor, all or part of the steps of the foregoing acoustic logging saturation waveform recovery method are implemented, and will not be repeated here.

[0125] Further, the computer program product may include one or more computer-executable components configured to perform the embodiments when the program runs; the computer program product may further include a computer program tangibly embodied on a computer-readable medium, the computer program including program code for performing any of the methods in the embodiments of the present disclosure. In such an embodiment, the computer program may be downloaded and installed from a network through a communication section, and / or installed from a removable medium.

[0126] The present application further provides an electronic device, which may include: one or more processors, a memory, a multimedia component, an input / output (I / O) interface, and a communication component.

[0127] Among them, the one or more processors are used to execute all or part of the steps of the acoustic logging saturation waveform recovery method as described above. The memory is used to store various types of data, which may include, for example, instructions of any application or method in the electronic device, and application-related data.

[0128] The one or more processors may be implemented by an application specific integrated circuit (ASIC), a digital signal processor (DSP), a digital signal processing device (DSPD), a programmable logic device (PLD), a field programmable gate array (FPGA), a controller, a microcontroller, a microprocessor, or other electronic components, and are used to execute all or part of the steps of the acoustic logging saturation waveform recovery method as described above.

[0129] The memory can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic memory, flash memory, magnetic disk or optical disc.

[0130] The multimedia component can include a screen and an audio component. The screen can be a touch screen. The audio component is used for outputting and / or inputting audio signals. For example, the audio component can include a microphone for receiving external audio signals. The received audio signals can be further stored in the memory or sent through the communication component. The audio component also includes at least one speaker for outputting audio signals.

[0131] The I / O interface provides an interface between one or more processors and other interface modules, and the other interface modules can be a keyboard, a mouse, buttons, etc. These buttons can be virtual buttons or physical buttons.

[0132] The communication component is used for wired or wireless communication between the electronic device and other devices. Wired communication includes communication through a network port, a serial port, etc.; wireless communication includes Wi-Fi, Bluetooth, near field communication (NFC), 2G, 3G, 4G, 5G, or a combination of one or more of them.

[0133] In summary, the present application provides a method, an apparatus, a computer-readable storage medium, and an electronic device for restoring a saturated waveform in acoustic logging. This method can solve the defect that due to the excessive acquisition gain setting of the acoustic logging instrument during the logging process, the waveform becomes saturated, resulting in the rejection of the acquired logging data due to non-compliance, and the need to re-acquire the acoustic logging data for part or even all well sections. By repositioning the leaked energy in the frequency spectrum, a complete signal can be restored. Specifically, it includes: obtaining a saturated waveform to be transformed by opening a time window locally in the entire acoustic waveform signal containing the saturated waveform, marking the saturated position in the initial time-domain saturated waveform as a first preset value through a preset saturation position marking function, and marking the non-saturated position in the initial time-domain saturated waveform as a second preset value; performing a linear integral transform on the initial time-domain saturated waveform to obtain linear integral transform data; preprocessing the linear integral transform data and performing an inverse transform on the preprocessed data to obtain the time-domain waveform after the inverse transform; traversing all time points in the time-domain waveform after the inverse transform, and when the amplitude value of the current time point is not greater than the saturation value and at the position marked as the first preset value by the preset saturation position marking function, setting the amplitude value of the current time point to the saturation value; otherwise, inserting the initial value at the corresponding position of the initial time-domain saturated waveform. After the traversal is completed, the processed time-domain waveform is obtained; when the current preset decreasing ratio coefficient is not less than the preset termination ratio coefficient or the current number of loops is less than the preset number of loops, gradually decreasing the given decreasing ratio coefficient and using the processed time-domain waveform as the time-domain saturated waveform to be linearly integrated and transformed, and then jumping to the linear integral transform processing step until the current given decreasing ratio coefficient is less than the preset termination ratio coefficient or the current number of loops is not less than the preset number of loops, obtaining the restored and unsaturated complete waveform.

[0134] It should also be understood that the methods or apparatuses disclosed in the embodiments provided in this application can also be implemented in other ways. The method or apparatus embodiments described above are merely illustrative. For example, the flowcharts and block diagrams in the accompanying drawings show the possible architectures, functions, and operations of the methods and apparatuses according to multiple embodiments of this application. In this regard, each block in the flowchart or block diagram may represent a module, a computer program segment, or a part of a computer program. A module, a computer program segment, or a part of a computer program contains one or more computer programs for implementing the specified logical functions. It should also be noted that in some alternative implementations, the functions marked in the blocks may occur in a different order than that marked in the accompanying drawings. In fact, they may also be executed substantially in parallel, and sometimes they may be executed in the reverse order, depending on the functions involved. It should also be noted that each block in the block diagram and / or flowchart, as well as the combination of blocks in the block diagram and / or flowchart, can be implemented by a dedicated hardware-based system for performing the specified functions or actions, or can be implemented by a combination of dedicated hardware and a computer program.

[0135] In this application, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, such that a process, method, article or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising one..." does not exclude the presence of additional identical elements in the process, method, apparatus or device comprising the element; if there is a description of "first", "second", etc., it is only for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features or implicitly specifying the sequence of the indicated technical features; in the description of this application, unless otherwise stated, the meaning of the terms "plural", "multiple" is at least two; if there is a description of a server, it should be noted that the server can be an independent physical server or terminal, or a server cluster composed of multiple physical servers, and can be a cloud server capable of providing basic cloud computing services such as cloud servers, cloud databases, cloud storage and CDN; in this application, if there is a description of a smart terminal or mobile device, it should be noted that the smart terminal or mobile device can be a mobile phone, tablet computer, smart watch, netbook, wearable electronic device, personal digital assistant (Personal Digital Assistant, abbreviated as PDA), augmented reality device (Augmented Reality, abbreviated as AR), virtual reality device (Virtual Reality, abbreviated as VR), smart TV, smart speaker, personal computer (Personal Computer, abbreviated as PC), etc., but is not limited thereto, and this application does not make special limitations on the specific form of the smart terminal or mobile device.

[0136] Finally, it should be noted that in the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "example", "one example" or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of this application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0137] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are all exemplary. The content described above is only an implementation manner adopted for the convenience of understanding the present application, and is not used to limit the present application. Any person skilled in the art within the technical field to which the present application pertains may make any modifications and changes in the form of implementation and details without departing from the spirit and scope disclosed by the present application. However, the protection scope of the present application shall still be subject to the scope defined by the appended claims.

Claims

1. A method for restoring a saturated waveform in acoustic logging, characterized in that, the method includes: Marking the saturated positions in the initial time-domain saturated waveform as a first preset value and the unsaturated positions in the initial time-domain saturated waveform as a second preset value through a preset saturated position marking function; Performing a linear integral transform process on the initial time-domain saturated waveform to obtain linear integral transform data; Preprocessing the linear integral transform data and performing an inverse transform on the preprocessed data to obtain an inverse-transformed time-domain waveform; Traversing all time points in the inverse-transformed time-domain waveform, and when the amplitude value of the current time point is not greater than the saturation value and at the position marked as the first preset value by the preset saturated position marking function, setting the amplitude value of the current time point to the saturation value; otherwise, inserting the initial value at the corresponding position of the initial time-domain saturated waveform, and obtaining a processed time-domain waveform after the traversal is completed; When the current given decreasing proportionality coefficient is not less than the preset termination proportionality coefficient or the current number of loops is less than the preset number of loops, gradually decreasing the given decreasing proportionality coefficient and using the processed time-domain waveform as the time-domain saturated waveform to be linearly integral-transformed and jumping to the linear integral transform processing step until the current given decreasing proportionality coefficient is less than the preset termination proportionality coefficient or the current number of loops is not less than the preset number of loops, obtaining a restored and unsaturated complete waveform.

2. The method for restoring a saturated waveform in acoustic logging according to claim 1, characterized in that, the obtaining method of the initial time-domain saturated waveform includes: Traversing the waveform data collected by acoustic logging, marking the single-channel data with local saturated waveforms, and opening a time window locally for the entire segment of the single-channel waveform, and extracting local waveform data containing several periods of saturated and unsaturated waveforms at the same time to obtain the initial time-domain saturated waveform.

3. The method for restoring a saturated waveform in acoustic logging according to claim 1, characterized in that, the linear integral transform includes a fast Fourier transform in the time domain; the inverse transform includes an inverse fast Fourier transform in the time domain.

4. The method for restoring a saturated waveform in acoustic logging according to claim 1, characterized in that, the initial time-domain saturated waveform includes: Waveform data received by an acoustic logging instrument with a monopole transmitting transducer, a dipole transmitting transducer or a quadrupole transmitting transducer.

5. The method for restoring a saturated waveform in acoustic logging according to claim 1, characterized in that, the initial time-domain saturated waveform includes: Waveform data received by a digital acoustic logging device, an array acoustic logging device or a cross-dipole acoustic logging device.

6. The method for restoring a saturated waveform in acoustic logging according to claim 1, characterized in that, the preprocessing of the saturated waveform after the linear integral transform and the inverse transform of the preprocessed data include: Setting the values of the part of the linear integral transform data that is not greater than a given decreasing threshold to 0, and keeping the other values unchanged to obtain preprocessed data; Performing an inverse transform on the preprocessed data.

7. An apparatus for restoring a saturated waveform in acoustic logging, characterized in that, it includes: A first processing module, configured to mark the saturation positions in the initial time-domain saturation waveform as a first preset value through a preset saturation position marking function, and mark the unsaturated positions in the initial time-domain saturation waveform as a second preset value; A linear integral transformation module, configured to perform a linear integral transformation process on the initial time-domain saturation waveform to obtain linear integral transformation data; An inverse transformation module, configured to preprocess the linear integral transformation data and perform an inverse transformation on the preprocessed data to obtain an inverse-transformed time-domain waveform; A traversal module, configured to traverse all time points in the inverse-transformed time-domain waveform, and when the amplitude value of the current time point is not greater than the saturation value and the current time point is marked as the first preset value by the preset saturation position marking function, set the amplitude value of the current time point to the saturation value; otherwise, insert the initial value at the corresponding position of the initial time-domain saturation waveform, and obtain a processed time-domain waveform after the traversal is completed; A second processing module, configured to, when the current given decreasing ratio coefficient is not less than a preset termination ratio coefficient or the current number of cycles is less than a preset number of cycles, gradually decrease the given decreasing ratio coefficient and use the processed time-domain waveform as the time-domain saturation waveform to be linearly integrally transformed, and jump to the linear integral transformation processing step until the current given decreasing ratio coefficient is less than the preset termination ratio coefficient or the current number of cycles is not less than the preset number of cycles, and obtain a restored and unsaturated complete waveform.

8. A computer-readable storage medium Characterized in that The computer program stored in the computer-readable storage medium, when executed by one or more processors, implements the acoustic logging saturation waveform restoration method according to any one of claims 1 to 6.

9. An electronic device Characterized in that It includes a memory and a processor, and a computer program is stored on the memory. When the computer program is executed by the processor, the acoustic logging saturation waveform restoration method according to any one of claims 1 to 6 is implemented.

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