A method and device for quality control of the fidelity of low-frequency seismic signals

Abstract

The present disclosure relates to a method and device for quality control of the fidelity of low-frequency seismic signals, and relates to the technical field of seismic data processing. Among them, the method for quality control of the fidelity of low-frequency seismic signals includes: using the obtained low-pass filtered low-frequency data volume of different frequencies of the target layer, the full-frequency structural interpretation horizon seismic data volume, the acoustic logging curve, and the synthetic seismogram; performing quality control on the low-pass filtered low-frequency data volume after descending sorting in sequence to obtain the low cut-off frequency of the quality control of the fidelity of the low-frequency seismic signal, thereby completing the quality control of the fidelity of the seismic signal. The embodiments of the present disclosure can solve the problem that in the process of processing previous seismic data, artificially generated low-frequency signals will be generated, and the fidelity of the artificially generated low-frequency signals is low and unreliable. Since interpreters cannot distinguish and eliminate the unreliable low-frequency signals, subsequent reservoir prediction and exploration will fail.

Description

Technical Field

[0001] The present disclosure relates to the technical field of seismic data processing, and particularly to a method and device for quality control of the fidelity of low-frequency seismic signals. Background Art

[0002] For decades, the low-frequency components in seismic signals have received increasing attention. The low-frequency signals below 10 Hz in seismic processing results play an increasingly important role in reservoir and fluid prediction, and in geological design, there are also processing requirements for broadband amplitude preservation and even explicit low-frequency preservation for seismic data processing.

[0003] However, not all low-frequency signals in the processing results come from seismic data acquisition that can truly reflect the underground situation. Some low-frequency signals are artificially generated during the processing through deconvolution, spectral whitening or shaping, and low-frequency compensation. The fidelity of these low-frequency signals is low and they should not be trusted in interpretation and reservoir and fluid prediction. For example, in a work area, through the original seismic single-shot frequency scan, it is confirmed that the lowest frequency is 6 Hz. During the entire processing process, deconvolution, spectral whitening, spectral shaping, or even direct low-frequency restoration or low-frequency compensation processing is performed. When performing spectral analysis, the lowest frequency may be as low as 3 Hz, but the part between 3 Hz and 6 Hz is generated through processing rather than the low-frequency information received during acquisition, and it is unreliable and untrustworthy. How to determine the credible and usable low frequencies in the processing results through quality control of seismic data is the most important link in the connection between processing and interpretation. If the quality control of low frequencies is missing, and interpreters blindly trust the low-frequency information provided by the processing data, it will produce large illusions and lead to failures in reservoir prediction and exploration. Summary of the Invention

[0004] The present disclosure proposes a technical solution for a method and device for quality control of the fidelity of low-frequency seismic signals. By obtaining the full-frequency structural interpretation horizon seismic data volume, acoustic logging curves, and synthetic seismograms, the quality control of the fidelity of the low-frequency signals in the seismic data is carried out, and the untrustworthy low-frequency components are efficiently and accurately identified and removed. To solve the problem that in the process of processing previous seismic data, artificially generated low-frequency signals will be produced, and the fidelity of the artificially generated low-frequency signals is low and untrustworthy. Because interpreters cannot distinguish and remove the untrustworthy low-frequency signals, it leads to failures in subsequent reservoir prediction and exploration.

[0005] According to one aspect of the present disclosure, a method for quality control of the fidelity of low-frequency seismic signals is provided, including: obtaining the low-pass filtered low-frequency data volume of different frequencies of the target layer, the full-frequency structural interpretation horizon seismic data volume, the acoustic logging curves, and the synthetic seismograms;

[0006] Sorting the low-pass filtered low-frequency data volume of different frequencies of the target layer in a decreasing order according to a predetermined increment;

[0007] Using the seismic data volume of the full-frequency structure interpretation horizon to perform quality control on the sorted low-pass filtered low-frequency data volume in sequence, to obtain the low cut-off frequency with structural constraint quality control;

[0008] Using the acoustic logging curve to perform quality control on the sorted low-pass filtered low-frequency data volume in sequence, to obtain the low cut-off frequency with well data constraint quality control;

[0009] Using the synthetic seismogram to perform quality control on the sorted low-pass filtered low-frequency data volume in sequence, to obtain the low cut-off frequency with synthetic seismogram quality control;

[0010] Compare the low cut-off frequency with structural constraint quality control, the low cut-off frequency with well data constraint quality control, and the low cut-off frequency with synthetic seismogram quality control, and select the maximum value among them as the low cut-off frequency for fidelity quality control of low-frequency seismic signals, to complete the fidelity quality control of seismic signals.

[0011] Preferably, the method for obtaining the low-pass filtered low-frequency data volume with different frequencies of the target layer includes:

[0012] Obtain seismic data, perform quality control on the availability of the seismic data, to obtain effective seismic data;

[0013] Perform frequency-divided low-pass filtering on the effective seismic data, to obtain the low-pass filtered low-frequency data volume with different frequencies.

[0014] Preferably, the method for performing quality control on the availability of seismic data to obtain effective seismic data includes:

[0015] Select seismic data with a length above a first predetermined time at the target layer of the seismic data, perform spectral analysis on the selected seismic data, and judge whether the low frequency in the selected seismic data is rich and whether there is no DC component at the first predetermined frequency. If so, pass the quality control to obtain effective seismic data.

[0016] Preferably, the method for using the seismic data volume of the full-frequency structure interpretation horizon to perform quality control on the sorted low-pass filtered low-frequency data volume in sequence to obtain the low cut-off frequency with structural constraint quality control includes:

[0017] Compare the sorted low-pass filtered low-frequency data volume with the seismic data volume of the full-frequency structure interpretation horizon in sequence respectively, and judge whether it conforms to the structural trend of the seismic data volume of the full-frequency structure interpretation horizon; if so, the quality control passes; if not, the quality control fails, end the judgment, and use the last low-pass filtered low-frequency data volume with passed quality control as the low cut-off frequency with structural constraint quality control.

[0018] Preferably, the method for comparing the sorted low-pass filtered low-frequency data volume with the seismic data volume of the full-frequency structural interpretation horizon in sequence and determining whether it conforms to the structural trend of the seismic data volume of the full-frequency structural interpretation horizon includes:

[0019] Taking the intermediate time point of the target layer on the seismic data volume of the full-frequency structural interpretation horizon as a reference, extracting amplitude attributes within a second predetermined time length range above and below it; taking the intermediate time point of the target layer on the low-pass filtered low-frequency data volume as a reference, extracting amplitude attributes within a second predetermined time length range above and below it, and determining whether there is an amplitude mutation or inversion with an area of more than a predetermined percentage between the amplitude attributes of the low-pass filtered low-frequency data volume and the amplitude attributes of the seismic data volume of the full-frequency structural interpretation horizon. If so, the structural trends of the two do not conform; if not, they conform.

[0020] Preferably, the method for successively performing quality control on the sorted low-pass filtered low-frequency data volume using the acoustic logging curve to obtain the low cut-off frequency of well data-constrained quality control includes:

[0021] Performing low-pass filtering on the acoustic logging curve to obtain a low-pass filtered spectrum of the well curve;

[0022] Performing spectral analysis on the sorted low-pass filtered low-frequency data volume, taking the same time range for the spectra of the low-pass filtered low-frequency data volume and the low-pass filtered spectrum of the well curve at the same frequency, and determining whether the degree of conformity between the two spectra is greater than or equal to a predetermined degree of conformity. If so, the quality control passes; if not, the quality control fails, ending the judgment, and taking the last low-pass filtered low-frequency data volume that passes the quality control as the low cut-off frequency of well data-constrained quality control.

[0023] Preferably, the method for successively performing quality control on the sorted low-pass filtered low-frequency data volume using synthetic seismograms to obtain the low cut-off frequency of synthetic seismogram quality control includes:

[0024] Adjusting the low-pass filtered low-frequency data volume to the same time-depth position as the synthetic seismogram;

[0025] Successively determining the similarity between the sorted low-pass filtered low-frequency data volume and the synthetic seismograms at the same frequency, and determining whether the similarity is greater than or equal to a predetermined similarity. If so, the quality control passes; if not, the quality control fails, ending the judgment, and taking the last low-pass filtered low-frequency data volume that passes the quality control as the low cut-off frequency of synthetic seismogram quality control.

[0026] Preferably, the method for obtaining synthetic seismograms includes:

[0027] Obtaining very low frequency wavelets and reflection coefficient sequences, and convolving the very low frequency wavelets with the reflection coefficient sequences to obtain a series of synthetic seismograms.

[0028] According to one aspect of the present disclosure, there is provided a low-frequency seismic signal fidelity quality control device, characterized by comprising:

[0029] An acquisition unit for acquiring a full-frequency structural interpretation horizon seismic data volume, a sonic logging curve, a synthetic seismic record, and a low-pass filtered low-frequency data volume of different frequencies of a target layer;

[0030] A quality control unit for sorting the low-pass filtered low-frequency data volumes of different frequencies in a decreasing order according to a predetermined increment, and successively performing quality control on the sorted low-pass filtered low-frequency data volumes by using the full-frequency structural interpretation horizon seismic data volume to obtain a structurally constrained quality control low cut-off frequency, successively performing quality control on the sorted low-pass filtered low-frequency data volumes by using the sonic logging curve to obtain a well data constrained quality control low cut-off frequency, and successively performing quality control on the sorted low-pass filtered low-frequency data volumes by using the synthetic seismic record to obtain a synthetic seismic record quality control low cut-off frequency;

[0031] A comparison unit for comparing the structurally constrained quality control low cut-off frequency, the well data constrained quality control low cut-off frequency, and the synthetic seismic record quality control low cut-off frequency, and selecting the maximum value among them as the low-frequency seismic signal fidelity quality control low cut-off frequency to complete the quality control of the seismic signal fidelity.

[0032] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and do not limit the present disclosure.

[0033] Other features and aspects of the present disclosure will become clear from the following detailed description of exemplary embodiments with reference to the accompanying drawings. Description of the Drawings

[0034] The accompanying drawings herein are incorporated into the specification and constitute a part of this specification. These drawings show embodiments consistent with the present disclosure and, together with the specification, are used to explain the technical solutions of the present disclosure.

[0035] Figure 1 A flowchart showing a low-frequency seismic signal fidelity quality control method according to an embodiment of the present disclosure. Detailed Embodiments

[0036] Various exemplary embodiments, features, and aspects of the present disclosure will be described in detail below with reference to the accompanying drawings. The same reference numerals in the drawings denote elements having the same or similar functions. Although various aspects of the embodiments are shown in the drawings, the drawings are not necessarily drawn to scale unless otherwise specified.

[0037] The special term "exemplary" here means "serving as an example, an embodiment, or illustrative". Any embodiment described as "exemplary" here is not necessarily to be construed as superior to or better than other embodiments.

[0038] As used herein, the term "and / or" is merely a description of the relationship between associated objects, indicating that there can be three relationships. For example, A and / or B can represent three cases: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the term "at least one" as used herein means any one of a plurality or any combination of at least two of a plurality. For example, including at least one of A, B, and C can mean including any one or more elements selected from the set composed of A, B, and C.

[0039] In addition, to better illustrate the present disclosure, numerous specific details are given in the following detailed implementation manners. Those skilled in the art should understand that the present disclosure can still be implemented without some specific details. In some instances, methods, means, elements, and circuits well-known to those skilled in the art are not described in detail to highlight the gist of the present disclosure.

[0040] Figure 1 A flowchart showing a method for quality control of the fidelity of low-frequency seismic signals according to an embodiment of the present disclosure is shown. As Figure 1 shown, a method for quality control of the fidelity of low-frequency seismic signals includes: Step 1: Obtain a full-frequency structural interpretation horizon seismic data volume, a sonic log curve, a synthetic seismic record, and a low-pass filtered low-frequency data volume of different frequencies of the target layer; Step 2: Sort the low-pass filtered low-frequency data volumes of different frequencies in decreasing order according to a predetermined increment; Step 3: Use the full-frequency structural interpretation horizon seismic data volume to perform quality control on the sorted low-pass filtered low-frequency data volumes in sequence to obtain a structurally constrained quality control low cut-off frequency; Step 4: Use the sonic log curve to perform quality control on the low-pass filtered low-frequency data volumes sorted in decreasing order in sequence to obtain a well-data constrained quality control low cut-off frequency; Step 5: Use the synthetic seismic record to perform quality control on the low-pass filtered low-frequency data volumes sorted in decreasing order in sequence to obtain a synthetic seismic record quality control low cut-off frequency; Step 6: Compare the structurally constrained quality control low cut-off frequency, the well-data constrained quality control low cut-off frequency, and the synthetic seismic record quality control low cut-off frequency, and select the maximum value as the low-frequency seismic signal fidelity quality control low cut-off frequency to complete the quality control of the fidelity of the seismic signal. To solve the problem that in the process of processing past seismic data, artificially generated low-frequency signals will be produced, and the fidelity of the artificially generated low-frequency signals is low and unreliable. Since interpreters cannot distinguish and eliminate the unreliable low-frequency signals, subsequent reservoir prediction and exploration will fail.

[0041] Step 1: Obtain a full-frequency structural interpretation horizon seismic data volume, a sonic log curve, a synthetic seismic record, and a low-pass filtered low-frequency data volume of different frequencies of the target layer.

[0042] In the present disclosure, the method for obtaining low-pass filtered low-frequency data volumes of different frequencies in the target layer includes: obtaining seismic data, performing quality control on the availability of the seismic data to obtain effective seismic data; and performing frequency-divided low-pass filtering on the effective seismic data to obtain low-pass filtered low-frequency data volumes of different frequencies.

[0043] In the present disclosure, the method for performing quality control on the availability of seismic data to obtain effective seismic data includes: selecting seismic data with a length of more than a first predetermined time length at the target layer of the seismic data, performing spectral analysis on the selected seismic data, and determining whether the low frequency in the selected seismic data is rich and whether there is no DC component of a first predetermined frequency. If so, the quality control is passed to obtain effective seismic data.

[0044] In an embodiment of the present disclosure, the method for determining whether the low frequency in the seismic data is rich includes: determining whether there is a low-frequency component below a second predetermined frequency in the spectrum at a predetermined decibel in the selected seismic data with a length of more than a first predetermined time length. If it exists, it indicates that the low frequency in the seismic data is rich and the quality control is passed. If it does not exist, the quality control cannot be passed. The first predetermined time length is 500 ms (milliseconds), and a time length of 500 ms or more can meet the minimum time width of the transformation; the predetermined decibel is -20 dB (decibels), because the amplitude wave energy below -20 dB is too small, so it is considered that the frequency is missing in the spectrum, and thus the predetermined decibel is selected at -20 dB; the second predetermined frequency is 10 Hz, and the frequency below 10 Hz in the seismic data is the low-frequency component.

[0045] Under the condition of rich low frequency, it is also necessary to determine whether there is a DC component of a first predetermined frequency in the selected seismic data with a length of more than 500 ms. The first predetermined frequency is 0 Hz; when there is a DC component of 0 Hz in the selected seismic data, it indicates that the seismic data has no processing value and cannot be used for subsequent seismic interpretation and reservoir prediction, so the quality control fails; if the low frequency in the selected seismic data is rich and there is no DC component of 0 Hz, the quality control is passed, indicating that the seismic data is effective and its fidelity quality control can be performed.

[0046] In an embodiment of the present disclosure, the low-pass filtering process is to remove the high-frequency components in the seismic data and retain the required low-frequency components, that is, retain the low-frequency components below 10 Hz and remove the high-frequency components greater than 10 Hz.

[0047] Step 2: Sort the low-pass filtered low-frequency data volumes of different frequencies in a decreasing order according to a predetermined increment.

[0048] In an embodiment of the present disclosure, the reserved low-frequency components are sorted from high to low according to a predetermined increment. Wherein, the predetermined increment is 1 Hz. After sorting, low-pass filtered low-frequency data volumes of 10 Hz, 9 Hz, 8 Hz, 7 Hz, 6 Hz, 5 Hz, 4 Hz, 3 Hz, 2 Hz, and 1 Hz will be obtained respectively. The sorted low-pass filtered low-frequency data volumes are used to facilitate subsequent quality control in descending order. When the quality control of the low-pass filtered data volume of a certain frequency fails, it means that the quality control of the low-pass filtered low-frequency data volumes behind it will all fail. Then, the quality control of the data volumes with smaller frequencies behind the low-pass filtered low-frequency data volume with failed quality control will no longer be performed, thereby improving efficiency.

[0049] Step 3: Use the full-frequency structural interpretation horizon seismic data volume to perform quality control on the sorted low-pass filtered low-frequency data volumes in sequence to obtain a structurally constrained quality control low cut-off frequency.

[0050] In the present disclosure, the method of using the full-frequency structural interpretation horizon seismic data volume to perform quality control on the sorted low-pass filtered low-frequency data volumes in sequence to obtain a structurally constrained quality control low cut-off frequency includes: comparing the sorted low-pass filtered low-frequency data volumes with the full-frequency structural interpretation horizon seismic data volume data in sequence to determine whether their structural trends conform to those of the full-frequency structural interpretation horizon seismic data volume; if so, the quality control passes; if not, the quality control fails, and the judgment ends. The last low-pass filtered low-frequency data volume with passed quality control is used as the structurally constrained quality control low cut-off frequency.

[0051] In the present disclosure, the method of comparing the sorted low-pass filtered low-frequency data volumes with the full-frequency structural interpretation horizon seismic data volume data in sequence to determine whether their structural trends conform to those of the full-frequency structural interpretation horizon seismic data volume includes: taking the middle time point of the target layer on the full-frequency structural interpretation horizon seismic data volume as a reference, extracting amplitude attributes within a second predetermined time length range above and below it; taking the middle time point of the target layer on the low-pass filtered low-frequency data volume as a reference, extracting amplitude attributes within a second predetermined time length range above and below it. Determine whether there is an amplitude mutation or inversion with an area of more than a predetermined percentage between the amplitude attributes of the low-pass filtered low-frequency data volume and the amplitude attributes of the full-frequency structural interpretation horizon seismic data volume. If so, their structural trends do not conform; if not, they conform.

[0052] In an embodiment of the present disclosure, taking the middle time point of the target layer on the full-frequency structural interpretation horizon seismic data volume as a reference, and taking the middle time point of the target layer on the low-pass filtered low-frequency data volume as a reference, amplitude attributes are respectively extracted within a predetermined second time length range above and below each. Wherein, the second time length is 10 ms, that is, amplitude attributes are extracted within a range of 10 ms above and below the middle time point of the target layer. The top, bottom, and middle interfaces of the target layer may be included within the 10 ms range.

[0053] When performing quality control, first compare the amplitude attribute map of the first low-pass filtered low-frequency data volume after sorting, that is, the amplitude attribute map of the 10 Hz low-pass filtered low-frequency data volume, with the amplitude attribute map of the full-frequency structural interpretation horizon seismic data volume to determine whether there is an amplitude mutation or inversion in an area above a predetermined percentage between the two. If the answer is no, it means that the amplitude mutation or inversion area between the two is below the predetermined percentage, and the structural coincidence trend between the 10 Hz low-pass filtered low-frequency data volume and the full-frequency structural interpretation horizon seismic data volume is good, that is, the structural trend conforms, and the quality control passes. Among them, the predetermined percentage is: 20%.

[0054] If the quality control of the 10 Hz low-pass filtered low-frequency data volume passes, then continue to compare the amplitude attribute of the next, that is, the 9 Hz low-pass filtered low-frequency data volume, with the amplitude attribute of the full-frequency structural interpretation horizon seismic data volume to determine whether there is an amplitude mutation or inversion in an area above 20% between the two. If the answer is yes, it means that there is a large range of time shift in the 9 Hz low-pass filtered low-frequency data volume, which does not conform to the structural trend of the full-frequency structural interpretation horizon seismic data volume, and the quality control fails, and the quality control ends, that is, no longer perform quality control on the low-pass filtered low-frequency data volume with a frequency below 9 Hz, and use the last low-pass filtered low-frequency data volume that passes the quality control, that is, the 10 Hz low-pass filtered low-frequency data volume, as the structural constraint quality control low cut-off frequency.

[0055] Step 4: Use the acoustic logging curve to perform quality control on the low-pass filtered low-frequency data volumes in descending order to obtain the well data constrained quality control low cut-off frequency.

[0056] In the present disclosure, the method of using the acoustic logging curve to perform quality control on the low-pass filtered low-frequency data volumes in descending order to obtain the well data constrained quality control low cut-off frequency includes: performing low-pass filtering on the acoustic logging curve to obtain a well curve low-pass filtered spectrum; performing spectral analysis on the sorted low-pass filtered low-frequency data volumes, taking the same time range for the spectra of the low-pass filtered low-frequency data volumes with the same frequency and the well curve low-pass filtered spectrum, and determining whether the degree of coincidence between the two spectra is greater than or equal to a predetermined degree of coincidence; if the answer is yes, the quality control passes; if the answer is no, the quality control fails, and the judgment ends, and the last low-pass filtered low-frequency data volume that passes the quality control is used as the well data constrained quality control low cut-off frequency.

[0057] In the embodiment of the present disclosure, perform low-pass filtering on the acoustic logging curve in the study area corresponding to the seismic data to obtain a well curve low-pass filtered spectrum from 10 Hz to 1 Hz. When performing quality control, first take the same time range for the first low-pass filtered low-frequency data volume after sorting, that is, the 10 Hz low-pass filtered low-frequency data volume, and the 10 Hz well curve low-pass filtered spectrum with the same frequency, and determine whether the degree of coincidence between the two spectra is greater than or equal to a predetermined degree of coincidence. If the answer is yes, the quality control passes. Among them, the predetermined degree of coincidence is 70%.

[0058] If the quality control of the low-pass filtered low-frequency data volume at 10 Hz passes, for the next low-pass filtered low-frequency data volume, that is, the low-pass filtered low-frequency data volume at 9 Hz and the low-pass filtered spectrum of the 9 Hz well curve at the same frequency, take the same time range. Judge that if the compliance degree between the spectra of the two is greater than or equal to 70%, the quality control passes, and continue to judge the compliance degrees of the low-pass filtered low-frequency data volumes at 8 Hz, 7 Hz, 6 Hz, and 5 Hz and the low-pass filtered spectra of the corresponding well curves at the same frequency in turn. If the compliance degree between the spectrum of the low-pass filtered low-frequency data volume at 5 Hz and the low-pass filtered spectrum of the 5 Hz well curve is less than 70% after judgment, the quality control fails, and the quality control of the low-pass filtered low-frequency data volume below 5 Hz will not continue; use the last low-pass filtered low-frequency data volume at 6 Hz that passes the quality control as the low cut-off frequency for well data constrained quality control. Among them, the spectrum analysis is: convert the low-pass filtered low-frequency data volume from the time domain to the frequency domain, and then determine the compliance degree between the converted low-pass filtered low-frequency data volume and the low-pass filtered spectrum of the well curve at the same frequency.

[0059] Step 5: Use the synthetic seismogram to perform quality control on the low-pass filtered low-frequency data volumes sorted in descending order in turn to obtain the low cut-off frequency for synthetic seismogram quality control.

[0060] In the present disclosure, the method of using the synthetic seismogram to perform quality control on the low-pass filtered low-frequency data volumes sorted in descending order in turn to obtain the low cut-off frequency for synthetic seismogram quality control includes: adjusting the low-pass filtered low-frequency data volume to the same time-depth position as the synthetic seismogram;

[0061] Determine the similarity between the sorted low-pass filtered low-frequency data volumes and the synthetic seismograms at the same frequency in turn, and judge whether the similarity is greater than or equal to a predetermined similarity; if so, the quality control passes; if not, the quality control fails, end the judgment, and use the last low-pass filtered low-frequency data volume that passes the quality control as the low cut-off frequency for synthetic seismogram quality control.

[0062] In the present disclosure, the method of obtaining the synthetic seismogram includes: obtaining a very low-frequency wavelet and a reflection coefficient sequence, and convolving the very low-frequency wavelet with the reflection coefficient sequence to obtain a series of synthetic seismograms.

[0063] In the embodiments of the present disclosure, the very low-frequency wavelet can be artificially set by the Ricker wavelet, and the reflection coefficient sequence is obtained during the previous seismic data processing; select the very low-frequency wavelet below 10 Hz to convolve with the reflection coefficient sequence, and a series of synthetic seismograms with main frequencies from 10 Hz to 1 Hz will be obtained.

[0064] During quality control, adjust the low-pass filtered low-frequency data volume to the same time-depth position as the synthetic seismogram, determine the first low-pass filtered low-frequency data volume after descending sorting, that is, the similarity between the 10 Hz low-pass filtered low-frequency data volume and the 10 Hz synthetic seismogram, and judge whether the similarity is greater than or equal to a predetermined similarity. If so, pass the quality control. Among them, the predetermined similarity is 80%.

[0065] If the quality control of the 10 Hz low-pass filtered low-frequency data volume passes, then quality control the 9 Hz low-pass filtered low-frequency data volume, determine the similarity between the 9 Hz low-pass filtered low-frequency data volume and the 9 Hz synthetic seismogram, and judge whether the similarity is greater than or equal to 80%. If so, the quality control passes. Then continue to quality control the 7 Hz, 6 Hz, 5 Hz, and 4 Hz low-pass filtered low-frequency data volumes in turn. If the similarity between the 4 Hz low-pass filtered low-frequency data volume and the 4 Hz synthetic seismogram is less than 80%, the quality control fails and the quality control ends, and no longer continue to quality control the low-pass filtered low-frequency data volume below 4 Hz. Take the 5 Hz low-pass filtered low-frequency data volume as the low cut-off frequency for the quality control of the synthetic seismogram. Among them, the similarity between the low-pass filtered low-frequency data volume and the synthetic seismogram of the same frequency can be obtained by performing a cross-correlation operation.

[0066] Step 6: Compare the structure-constrained quality control low cut-off frequency, well data-constrained quality control low cut-off frequency, and synthetic seismogram quality control low cut-off frequency, and select the maximum value among them as the low cut-off frequency for the fidelity quality control of the low-frequency seismic signal, and complete the fidelity quality control of the seismic signal.

[0067] In the embodiment of the present disclosure, comparing the structure-constrained quality control low cut-off frequency, well data-constrained quality control low cut-off frequency, and synthetic seismogram quality control low cut-off frequency obtained after steps 3, 4, and 5 is to compare the structure-constrained quality control low cut-off frequency of 10 Hz obtained in step 3, the well data-constrained quality control low cut-off frequency of 6 Hz obtained in step 4, and the synthetic seismogram quality control low cut-off frequency of 5 Hz obtained in step 5, and select the maximum value, that is, the structure-constrained quality control low cut-off frequency of 10 Hz obtained in step 3 as the final low cut-off frequency for the fidelity quality control of the low-frequency seismic signal. After high-pass filtering the seismic data through this low cut-off frequency of 10 Hz for the fidelity quality control of the low-frequency seismic signal, the output is obtained, thereby completing the quality control.

[0068] The execution entity of the low-frequency seismic signal fidelity quality control method can be a low-frequency seismic signal fidelity quality control device. For example, the low-frequency seismic signal fidelity quality control method can be executed by a terminal device, a server, or other processing devices. Among them, the terminal device can be a user equipment (UE), a mobile device, a user terminal, a terminal, a cellular phone, a cordless phone, a personal digital assistant (PDA), a handheld device, a computing device, a vehicle-mounted device, a wearable device, etc. In some possible implementation manners, the low-frequency seismic signal fidelity quality control method can be implemented by a processor calling computer-readable instructions stored in a memory.

[0069] Those skilled in the art can understand that in the above method of the specific implementation manner, the writing order of each step does not mean a strict execution order that constitutes any limitation on the implementation process. The specific execution order of each step should be determined according to its function and possible internal logic.

[0070] The present disclosure also proposes a low-frequency seismic signal fidelity quality control device. The low-frequency seismic signal fidelity quality control device includes: an acquisition unit, configured to acquire a full-frequency structural interpretation horizon seismic data volume, a sonic logging curve, a synthetic seismogram, and a low-pass filtered low-frequency data volume of different frequencies of a target layer; a quality control unit, configured to perform a decreasing sorting on the low-pass filtered low-frequency data volume of different frequencies according to a predetermined increment, and successively perform quality control on the sorted low-pass filtered low-frequency data volume by using the full-frequency structural interpretation horizon seismic data volume to obtain a structure-constrained quality control low cut-off frequency, perform quality control on the sorted low-pass filtered low-frequency data volume by using the sonic logging curve to obtain a well-data-constrained quality control low cut-off frequency, and perform quality control on the sorted low-pass filtered low-frequency data volume by using the synthetic seismogram to obtain a synthetic seismogram quality control low cut-off frequency; a comparison unit, configured to compare the structure-constrained quality control low cut-off frequency, the well-data-constrained quality control low cut-off frequency, and the synthetic seismogram quality control low cut-off frequency, and select the maximum value among them as the low-frequency seismic signal fidelity quality control low cut-off frequency to complete the quality control of the seismic signal fidelity.

[0071] In some embodiments, the functions or the included units and modules of the device provided by the embodiments of the present disclosure can be used to execute the low-frequency seismic signal fidelity quality control method described in the above method embodiments. The specific implementation can refer to the description of the above method embodiments. For the sake of brevity, it will not be repeated here.

[0072] The core of the present invention is to firstly conduct usability quality control on seismic data. If the original seismic data has a DC component of 0Hz or does not have a low-frequency component below 10Hz, the direct quality control fails and the seismic data under quality control is deemed unavailable. Whether the low-frequency component conforms to the structural trend, the method adopted is to quality control the full-frequency structural interpretation layer seismic data body on the profile. When the low-pass filtered low-frequency data body profile is through the layer, the amplitude attribute is extracted by the layer constraint to perform plane structural matching degree quality control. After the acoustic logging curve spectrum is low-pass filtered, it is compared with the spectrum of the low-pass filtered low-frequency data body for quality control. If the degree of conformity is higher than 70%, the frequency low frequency is reliable. Using very low-frequency sub-waves below 10Hz to make artificial synthetic seismic records and compare them with the low-pass filtered low-frequency data body for quality control. If the similarity with the synthetic seismic record is higher than 80%, the frequency low frequency is reliable. The present invention eliminates unreliable low-frequency components that are not collected through well-seismic joint quality control, and efficiently and accurately identifies the fidelity of the low-frequency components of the processing results, providing reliable basic data for subsequent applications.

[0073] It can be understood that the above-mentioned various method embodiments mentioned in the present disclosure can be combined with each other to form a combined embodiment without violating the principle logic. Due to space limitations, the present disclosure will not go into details.

[0074] Those skilled in the art will appreciate that, in the above method of specific implementation, the order in which the steps are written does not imply a strict execution order and does not constitute any limitation on the implementation process. The specific execution order of the steps should be determined by their functions and possible internal logic.

[0075] The embodiments of the present disclosure have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or technical improvements to the technology in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A method for quality control of the fidelity of low-frequency seismic signals, characterized in that, it includes: Obtaining low-pass filtered low-frequency data volumes of different frequencies in the target layer, full-frequency structural interpretation horizon seismic data volumes, acoustic logging curves, and synthetic seismograms; Sorting the low-pass filtered low-frequency data volumes of different frequencies in the target layer in descending order at a predetermined increment; Using the full-frequency structural interpretation horizon seismic data volume to sequentially perform quality control on the sorted low-pass filtered low-frequency data volumes to obtain a structurally constrained quality control low cut-off frequency, and the method includes; Performing low-pass filtering on the acoustic logging curve to obtain a low-pass filtered spectrum of the well curve; Performing spectral analysis on the sorted low-pass filtered low-frequency data volumes, taking the same time range for the spectra of the low-pass filtered low-frequency data volumes of the same frequency and the low-pass filtered spectrum of the well curve, and judging whether the compliance of the spectra between the two is greater than or equal to a predetermined compliance; if so, the quality control passes; if not, the quality control fails, ending the judgment, and taking the last low-pass filtered low-frequency data volume that passes the quality control as the well data constrained quality control low cut-off frequency; Using the acoustic logging curve to sequentially perform quality control on the low-pass filtered low-frequency data volumes sorted in descending order to obtain a well data constrained quality control low cut-off frequency; Using the synthetic seismogram to sequentially perform quality control on the low-pass filtered low-frequency data volumes sorted in descending order to obtain a synthetic seismogram quality control low cut-off frequency; Comparing the structurally constrained quality control low cut-off frequency, the well data constrained quality control low cut-off frequency, and the synthetic seismogram quality control low cut-off frequency, and selecting the maximum value among them as the low-frequency seismic signal fidelity quality control low cut-off frequency to complete the quality control of the seismic signal fidelity.

2. The method for quality control of the fidelity of low-frequency seismic signals according to claim 1, characterized in that, the method for obtaining the low-pass filtered low-frequency data volumes of different frequencies in the target layer includes: Obtaining seismic data, performing quality control on the availability of the seismic data to obtain effective seismic data; Performing frequency-divided low-pass filtering on the effective seismic data to obtain low-pass filtered low-frequency data volumes of different frequencies.

3. The method for quality control of the fidelity of low-frequency seismic signals according to claim 2, characterized in that, the method for performing quality control on the availability of the seismic data to obtain effective seismic data includes: Selecting seismic data with a length of more than a first predetermined time at the target layer of the seismic data, performing spectral analysis on the selected seismic data, and judging whether the low frequency in the selected seismic data is rich and whether there is no DC component of the first predetermined frequency; if so, the quality control passes to obtain effective seismic data.

4. The method for quality control of the fidelity of low-frequency seismic signals according to claim 1, characterized in that, the method for using the full-frequency structural interpretation horizon seismic data volume to sequentially perform quality control on the sorted low-pass filtered low-frequency data volumes to obtain a structurally constrained quality control low cut-off frequency includes: The sorted low-pass filtered low-frequency data volume is successively compared with the seismic data volume of the full-frequency structural interpretation horizon to determine whether its structural trend conforms to that of the seismic data volume of the full-frequency structural interpretation horizon; if so, the quality control passes; if not, the quality control fails, the judgment ends, and the last low-pass filtered low-frequency data volume that passes the quality control is used as the low cut-off frequency for structural constraint quality control.

5. The low-frequency seismic signal fidelity quality control method according to claim 4, characterized in that the method of successively comparing the sorted low-pass filtered low-frequency data volume with the seismic data volume of the full-frequency structural interpretation horizon to determine whether its structural trend conforms to that of the seismic data volume of the full-frequency structural interpretation horizon includes: Taking the middle time point of the target layer on the seismic data volume of the full-frequency structural interpretation horizon as a reference, extracting the amplitude attribute within a second predetermined time length range above and below it, taking the middle time point of the target layer on the low-pass filtered low-frequency data volume as a reference, and extracting the amplitude attribute within a second predetermined time length range above and below it, and determining whether there is an amplitude mutation or inversion with an area of more than a predetermined percentage between the amplitude attributes of the low-pass filtered low-frequency data volume and the seismic data volume of the full-frequency structural interpretation horizon; if so, their structural trends do not conform; if not, they conform.

6. The low-frequency seismic signal fidelity quality control method according to claim 1, characterized in that the method of successively performing quality control on the sorted low-pass filtered low-frequency data volume using the synthetic seismic record to obtain the low cut-off frequency for synthetic seismic record quality control includes; Adjusting the low-pass filtered low-frequency data volume to the same time-depth position as the synthetic seismic record; Successively determining the similarity between the sorted low-pass filtered low-frequency data volume and the synthetic seismic record of the same frequency, and determining whether the similarity is greater than or equal to a predetermined similarity; If so, the quality control passes; if not, the quality control fails, the judgment ends, and the last low-pass filtered low-frequency data volume that passes the quality control is used as the low cut-off frequency for synthetic seismic record quality control.

7. The low-frequency seismic signal fidelity quality control method according to any one of claims 1-6, characterized in that the method for obtaining the synthetic seismic record includes: Obtaining a very low-frequency wavelet and a reflection coefficient sequence, and convolving the very low-frequency wavelet with the reflection coefficient sequence to obtain a series of synthetic seismic records.

8. A low-frequency seismic signal fidelity quality control device, characterized in that it includes: An acquisition unit for acquiring the seismic data volume of the full-frequency structural interpretation horizon, the acoustic logging curve, the synthetic seismic record, and the low-pass filtered low-frequency data volume of different frequencies of the target layer; A quality control unit is configured to perform a decreasing sort on the low-pass filtered low-frequency data volumes of different frequencies at a predetermined increment, and successively perform quality control on the sorted low-pass filtered low-frequency data volumes using the full-frequency structural interpretation horizon seismic data volume to obtain a structurally constrained quality control low cut-off frequency, perform quality control on the sorted low-pass filtered low-frequency data volumes successively using the acoustic logging curve to obtain a well data constrained quality control low cut-off frequency, and perform quality control on the sorted low-pass filtered low-frequency data volumes successively using the synthetic seismogram to obtain a synthetic seismogram quality control low cut-off frequency; A comparison unit is configured to compare the structurally constrained quality control low cut-off frequency, the well data constrained quality control low cut-off frequency, and the synthetic seismogram quality control low cut-off frequency, and select the maximum value among them as the low-frequency seismic signal fidelity quality control low cut-off frequency to complete the fidelity quality control of the seismic signal.

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