Near-surface Q-compensation methods, devices, equipment and storage media

Abstract

This application discloses a near-surface Q-compensation method, apparatus, device, and storage medium, relating to the field of seismic exploration technology. It includes: acquiring seismic waves received by geophones in a receiving well, wherein the receiving well is equipped with at least three geophones located at geophone points at different depths within the receiving well; determining layer Q values ​​for different candidate strata based on the received frequency and propagation time of the seismic waves, wherein the different candidate strata are located at different stratum depths; fitting a QV scale based on the layer Q values ​​of the different candidate strata, the stratum depths, and a near-surface velocity field, wherein the near-surface velocity field characterizes the relationship between stratum depth and stratum velocity, and the QV scale characterizes the relationship between layer Q values ​​and stratum velocity; constructing a near-surface Q-field based on the QV scale and the near-surface velocity field; and performing near-surface Q-compensation processing based on the near-surface Q-field.

Description

Technical Field

[0001] This application relates to the field of seismic exploration technology, and in particular to a near-surface Q-compensation method, apparatus, equipment, and storage medium. Background Technology

[0002] As seismic exploration deepens, the exploration targets have gradually shifted from structural oil and gas reservoirs to lithologic oil and gas reservoirs, placing increasingly higher demands on the accuracy of these targets. Furthermore, it requires the differentiation of small geological bodies such as thin interbedded layers, thus imposing higher requirements on the resolution and amplitude preservation of seismic data. With further research, the quality factor Q compensation technique has emerged as an effective method to eliminate the absorption and attenuation effects of incompletely elastic media on seismic waves, thereby improving the resolution and amplitude preservation of seismic data. Obtaining accurate near-surface Q values ​​is crucial for achieving near-surface Q compensation.

[0003] Single-well and dual-well micrologging data can be used to determine near-surface Q-values ​​due to their data characteristics. Dual-well micrologging offers advantages over single-well micrologging in terms of both the principle and accuracy of Q-value determination. However, the dual-well micrologging method used in related technologies does not fully utilize the information from both wells. It only uses bottom-hole and surface geophones to determine Q-values. Its algorithm assumes a simple single- or double-layer structure near the surface, neglecting other geophones within the well, and the resulting Q-value is a single-point, single-value, leading to low accuracy. Summary of the Invention

[0004] This application provides a near-surface Q-compensation method, apparatus, device, and storage medium. The technical solution is as follows:

[0005] On one hand, embodiments of this application provide a near-surface Q compensation method, the method comprising:

[0006] The seismic wave received by the geophone in the receiving well is acquired. The receiving well is equipped with at least three geophones, and the at least three geophones are located at geophone points at different depths in the receiving well. The seismic wave is generated by the excitation point in the excitation well, and different excitation points are set at different depths in the excitation well.

[0007] Based on the received frequency and propagation time of the seismic waves, the layer Q value of different candidate strata is determined, wherein the different candidate strata are located at different stratum depths;

[0008] Based on the layer Q value, layer depth, and near-surface velocity field of different candidate strata, a QV scale is obtained by fitting. The near-surface velocity field is used to characterize the relationship between layer depth and layer velocity. The QV scale is used to characterize the relationship between layer Q value and layer velocity.

[0009] Construct a near-surface Q-field based on the QV scale and the near-surface velocity field;

[0010] Near-surface Q-compensation processing is performed based on the near-surface Q-field.

[0011] On the other hand, embodiments of this application provide a near-surface Q-compensation device, the device comprising:

[0012] A seismic wave acquisition module is used to acquire seismic waves received by detectors in a receiving well. The receiving well is equipped with at least three detectors, which are located at different depths in the receiving well. The seismic waves are generated by excitation points in an excitation well, and different excitation points are located at different depths in the excitation well.

[0013] The Q-value determination module is used to determine the layer Q-value of different candidate strata based on the receiving frequency and propagation time of the seismic waves, wherein the different candidate strata are located at different stratum depths.

[0014] The QV scale fitting module is used to fit a QV scale based on the layer Q value, the layer depth, and the near-surface velocity field of different candidate strata. The near-surface velocity field is used to characterize the relationship between the layer depth and the layer velocity, and the QV scale is used to characterize the relationship between the layer Q value and the layer velocity.

[0015] The Q-field construction module is used to construct the near-surface Q-field based on the QV scale and the near-surface velocity field.

[0016] The Q-value compensation module is used to perform near-surface Q-compensation processing based on the near-surface Q-field.

[0017] On the other hand, embodiments of this application provide a computer device including a processor and a memory; the memory stores at least one instruction, which is executed by the processor to implement the near-surface Q-compensation method as described above.

[0018] On the other hand, embodiments of this application provide a computer-readable storage medium storing at least one piece of program code, which is loaded and executed by a processor to implement the near-surface Q-compensation method as described above.

[0019] In this embodiment, seismic waves received by at least three geophones at different depths in the receiving well are acquired. Based on the received frequency and propagation time of the seismic waves, layer Q values ​​of different candidate strata can be determined. Furthermore, based on the obtained layer Q values, stratum depths, and near-surface velocity fields of the different candidate strata, a QV scale is fitted. A near-surface Q field is then constructed based on the QV scale and the near-surface velocity field, and near-surface Q compensation processing is performed based on the near-surface Q field. By employing the scheme provided in this embodiment, by setting at least three geophones at different depths in the receiving well, multi-layer Q values ​​can be obtained based on the seismic wave data received by the geophones, improving the accuracy of Q value estimation. Moreover, by fitting the QV scale, the near-surface Q field can be obtained by fitting the near-surface velocity field, further improving the accuracy of the near-surface Q field. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 A schematic diagram of an implementation environment provided by an exemplary embodiment of this application is shown;

[0022] Figure 2 A flowchart of a near-surface Q-compensation method provided in an exemplary embodiment of this application is shown;

[0023] Figure 3 This is a schematic diagram of dual-well micro-logging exploration provided in an exemplary embodiment of this application;

[0024] Figure 4 A flowchart of a near-surface Q-compensation method provided in another exemplary embodiment of this application is shown;

[0025] Figure 5 This is a schematic diagram of different detectors receiving seismic waves generated from the same excitation point, provided in an exemplary embodiment of this application.

[0026] Figure 6 This is a schematic diagram of wavelet truncation provided in an exemplary embodiment of this application;

[0027] Figure 7 This is a schematic diagram of spectrum analysis provided in an exemplary embodiment of this application;

[0028] Figure 8 This is a schematic diagram of the same detector receiving seismic waves generated from different excitation points, provided in an exemplary embodiment of this application.

[0029] Figure 9 A flowchart of a near-surface Q-compensation method provided in another exemplary embodiment of this application is shown;

[0030] Figure 10 This is a schematic diagram of all detectors receiving seismic waves generated from the same excitation point, provided in an exemplary embodiment of this application;

[0031] Figure 11 This is a schematic diagram illustrating multiple Q values ​​corresponding to the same candidate stratum, provided in an exemplary embodiment of this application.

[0032] Figure 12 This is a schematic diagram of the near-surface Q-field provided in an exemplary embodiment of this application;

[0033] Figure 13 This is a structural block diagram of a near-surface Q-compensation device provided in an exemplary embodiment of this application;

[0034] Figure 14 A structural block diagram of a computer device provided in an exemplary embodiment of this application is shown. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0036] Please refer to Figure 1 The diagram illustrates an implementation environment provided by an exemplary embodiment of this application. This implementation environment includes a computer device 110 and a dual-well micro-logging system 120.

[0037] Computer device 110 is an electronic device with Q-value estimation functionality. This Q-value estimation functionality can be a native application within the computer device or a function of a third-party application; the electronic device can be a smartphone, tablet, personal computer, wearable device, or in-vehicle terminal, etc. Figure 1 The example provided uses computer device 110 as a personal computer with a Q-value estimation application installed, but this is not intended to limit the scope of the example.

[0038] The dual-well micro-logging system 120 includes an excitation well 1210 and a receiving well 1220. The excitation well 1210 is provided with an excitation point for generating seismic waves by exciting the shot point. The receiving well 1220 is provided with a geophone point for receiving seismic waves. The depths of the excitation well 1210 and the receiving well 1220 can be the same or different. This application embodiment does not limit this.

[0039] Indicative, such as Figure 1As shown, computer device 110 acquires seismic exploration data from dual-well micro-logging system 120. When a shot point is activated at a trigger point in trigger well 1210, the trigger point generates seismic waves. The geophone at the geophone point in receiving well 1220 receives the seismic waves, and computer device 110 acquires the seismic wave data. Thus, computer device 110 calculates the layer Q value based on the acquired seismic wave data.

[0040] Please refer to Figure 2 This document illustrates a flowchart of a near-surface Q-compensation method provided in an exemplary embodiment of this application. This embodiment uses this method for... Figure 1 Taking the computer device shown as an example, the method may include the following steps:

[0041] Step 201: Obtain the seismic waves received by the geophones in the receiving well. The receiving well is equipped with at least three geophones, which are located at geophone points at different depths in the receiving well. The seismic waves are generated by the excitation points in the excitation well, and different excitation points are located at different depths in the excitation well.

[0042] In one possible implementation, the excitation well is provided with at least three excitation points at different depths, and each excitation point is provided with a corresponding shot point. The depth of the excitation point can be determined according to the required accuracy of the exploration data or according to the geological conditions of the well point. This application embodiment does not limit this.

[0043] Optionally, the excitation points can be determined at equal depths, or they can follow the principle of denser shallow layers and sparser deep layers, with the distance gradually increasing with depth. This application does not limit this.

[0044] Unlike related technologies, which only set geophones at the bottom of the receiving well and the ground, in this embodiment, in order to estimate the Q value of multiple layers, at least three geophones at different depths are set in the receiving well. When a seismic wave is generated at one of the excitation points, the computer device acquires the seismic waves received by the geophones at at least two geophones in the receiving well.

[0045] Optionally, the detector points in the receiving well can be distributed at the same depth as the excitation points in the excitation well, or they can be distributed at different depths. This application embodiment does not limit this.

[0046] In one possible implementation, each excitation point in the excitation well is sequentially excited by shot point to generate corresponding seismic waves, and the computer equipment sequentially acquires each seismic wave received by each geophone in the receiving well.

[0047] In one possible implementation, based on the distance between each excitation point and each detector point, the computer device acquires the seismic waves received by at least two detectors in the receiving well that are relatively close to each excitation point.

[0048] Indicative, such as Figure 3 As shown, five excitation points at different depths are set in the excitation well 301, namely the first excitation point 3011, the second excitation point 3012, the third excitation point 3013, the fourth excitation point 3014, and the fifth excitation point 3015. Five detector points at different depths are set in the receiving well 302, namely the first detector point 3021, the second detector point 3022, the third detector point 3023, the fourth detector point 3024, and the fifth detector point 3025. When the third excitation point 3013 is shot-point excited, the computer equipment acquires the seismic waves received by the five detectors in the receiving well 302. Alternatively, the computer equipment acquires the seismic waves received by the detectors at the second detector point 3022, the third detector point 3023, and the fourth detector point 3024, which are close to the third excitation point 3013.

[0049] Step 202: Based on the received frequency and propagation time of the seismic waves, determine the layer Q value of different candidate strata, where different candidate strata are located at different stratum depths.

[0050] Optionally, candidate formations can be divided directly based on excitation points at different depths set in the excitation well, or directly based on detector points at different depths set in the receiving well, or divided separately based on excitation points and detector points at different formation depths according to the specific formation structure at the well location. This application embodiment does not limit this.

[0051] In one possible implementation, after a shot point in the ignition well is ignited, the generated seismic wave propagates through the strata to reach various geophones, where the seismic wave is received by each geophone. The time it takes for the seismic wave to travel from the ignition point to the geophone is the propagation time of the seismic wave, and the peak frequency of the seismic wave when it reaches the geophone is the receiving frequency of the seismic wave.

[0052] In one possible implementation, the computer device determines the layer Q value corresponding to the candidate strata between each pair of geophones based on the received frequency and propagation time of the seismic waves received by each geophone.

[0053] In one possible implementation, the computer device determines the layer Q value corresponding to the candidate strata between each pair of excitation points based on the received frequency and propagation time of the seismic waves generated by the two excitation points received by the same detector.

[0054] Indicative, such as Figure 3As shown, when shot point excitation is performed at the third excitation point 3013, the computer equipment acquires the seismic waves received by each geophone in the receiving well 302, and divides the formation into four candidate strata based on the depth of each geophone, namely the first candidate stratum Q1, the second candidate stratum Q2, the third candidate stratum Q3, and the fourth candidate stratum Q4. Therefore, based on the propagation time and receiving frequency of the seismic waves received by the geophones at the first geophone point 3021 and the second geophone point 3022, the computer equipment can determine the layer Q value of the first candidate stratum Q1. Based on the propagation time and reception frequency of seismic waves received by the geophones at the second geophone point 3022 and the third geophone point 3023, the layer Q value of the second candidate stratum Q2 can be determined. Based on the propagation time and reception frequency of seismic waves received by the geophones at the third geophone point 3023 and the fourth geophone point 3024, the layer Q value of the third candidate stratum Q3 can be determined. Based on the propagation time and reception frequency of seismic waves received by the geophones at the fourth geophone point 3024 and the fifth geophone point 3025, the layer Q value of the fourth candidate stratum Q4 can be determined.

[0055] Step 203: Based on the layer Q value, layer depth and near-surface velocity field of different candidate strata, a QV scale is fitted. The near-surface velocity field is used to characterize the relationship between layer depth and layer velocity, and the QV scale is used to characterize the relationship between layer Q value and layer velocity.

[0056] In one possible implementation, a computer device acquires a near-surface velocity field near the excitation well and the receiving well, which characterizes the relationship between formation depth and formation velocity, where formation velocity refers to the propagation speed of seismic waves in the formation.

[0057] Optionally, the near-surface velocity field can be obtained by tomographic inversion, surface survey, or other methods that can obtain a more accurate near-surface velocity field. This application does not limit this method.

[0058] Since different candidate strata are located at different strata depths, and the number of excitation points set in the excitation well and the number of detector points set in the receiving well are limited, only a limited number of layer Q values ​​corresponding to different depths can be obtained, rather than continuous layer Q values ​​at different depths. However, based on the relationship between strata depth and strata velocity characterized by the near-surface velocity field, relatively dense and continuous strata velocity values ​​can be obtained. Thus, based on the strata depth, the strata velocities corresponding to the limited number of layer Q values ​​can be obtained.

[0059] In one possible implementation, the computer device obtains the corresponding formation velocity based on the formation depth corresponding to the layer Q value. The layer Q value and the formation velocity are in one-to-one correspondence, thereby fitting a QV scale, i.e., the QV relationship curve.

[0060] Step 204: Construct the near-surface Q field based on the QV scale and the near-surface velocity field.

[0061] In one possible implementation, since the QV gauge characterizes the relationship between continuous formation velocity and layer Q value, and the near-surface velocity field characterizes the relationship between continuous formation depth and formation velocity, the computer device can establish a near-surface Q field characterizing continuous formation depth and layer Q value based on the QV gauge and the near-surface velocity field.

[0062] Step 205: Perform near-surface Q-compensation processing based on the near-surface Q-field.

[0063] Furthermore, the computer equipment performs near-surface Q-compensation processing based on the near-surface Q-field to compensate for the attenuation of seismic data, thereby improving the resolution and amplitude preservation of the seismic data.

[0064] In summary, in this embodiment, by acquiring seismic waves received by at least three geophones at different depths in the receiving well, the layer Q values ​​of different candidate strata can be determined based on the received seismic wave frequency and propagation time. Furthermore, based on the obtained layer Q values, stratum depth, and near-surface velocity field of different candidate strata, a QV scale is fitted, and a near-surface Q field is constructed based on the QV scale and the near-surface velocity field. Finally, near-surface Q compensation processing is performed based on the near-surface Q field. Using the scheme provided in this embodiment, by setting at least three geophones at different depths in the receiving well, multiple layers of Q values ​​can be obtained based on the seismic wave data received by the geophones, improving the accuracy of Q value estimation. Moreover, by fitting the QV scale, the near-surface Q field can be obtained by fitting the near-surface velocity field, further improving the accuracy of the near-surface Q field.

[0065] In one possible implementation, in order to improve the accuracy of layer Q value calculation, it is necessary to obtain relatively complete and specific seismic wave data and perform calculation analysis. The process is described in detail below.

[0066] Please refer to Figure 4 This illustrates a flowchart of a near-surface Q-compensation method provided in another exemplary embodiment of this application. The method may include the following steps:

[0067] Step 401: Obtain the seismic waves received by the geophones in the receiving well. The receiving well is equipped with at least three geophones, which are located at geophone points at different depths in the receiving well. The seismic waves are generated by the excitation point in the excitation well, and different excitation points are set at different depths in the excitation well.

[0068] The implementation method of this step can refer to step 201 above, and will not be repeated here.

[0069] Step 402: The seismic wave received by the detector is truncated into a wavelet to obtain a seismic wavelet, which is a complete waveform segment of the first arrival seismic wave.

[0070] In one possible implementation, since seismic waves attenuate continuously as they propagate through the strata, in order to obtain a relatively accurate seismic wavelet, computer equipment performs wavelet truncation on the seismic waves received by the detector, thereby obtaining the seismic wavelet.

[0071] In one possible implementation, since the first-arrival seismic wave is the first wave to arrive at the detector and has a relatively complete waveform, the computer equipment performs wavelet extraction on the first-arrival seismic wave to obtain a complete waveform segment of the first-arrival seismic wave, which is the seismic wavelet.

[0072] Indicative, such as Figure 5 As shown, when the firing point 5011 in the firing well 501 is fired to generate seismic waves, the computer equipment performs wavelet extraction on the seismic waves received by the first detector at the first detector point 5021 in the receiving well 502 and the seismic waves received by the second detector at the second detector point 5022.

[0073] Indicative, such as Figure 6 As shown, the computer equipment obtains the seismic wavelet after performing wavelet interception on the seismic waves received by the first detector at the first detector point 5021 and the seismic waves received by the second detector at the second detector point 5022.

[0074] Step 403: Perform spectral analysis on the seismic wavelet to obtain the receiving frequency of the seismic wavelet.

[0075] Furthermore, the computer equipment performs spectral analysis on the intercepted seismic wavelet to obtain the peak frequency of the seismic wavelet reaching the receiver point, i.e., the receiving frequency.

[0076] Indicative, such as Figure 7 As shown, the computer equipment performs spectral analysis on the seismic wavelets intercepted at the first detector point 5021 and the second detector point 5022. According to the spectral curve analysis, the receiving frequency of the first seismic wavelet at the first detector point 5021 is f1, and the receiving frequency of the second seismic wavelet at the second detector point 5022 is f2.

[0077] Step 404: Determine the formation depth of the candidate formation based on the detector point depth corresponding to the detector point, or the excitation point depth of the excitation point.

[0078] In one possible implementation, in order to facilitate the calculation of the layer Q value based on the propagation duration and the receiving frequency, the computer device can directly determine the formation depth of the candidate formation based on the detector point depth of the corresponding detector point or the excitation point depth of the excitation point.

[0079] In one possible implementation, the computer device determines the formation depth of the candidate strata based on the first geophone depth corresponding to the first geophone point and the second geophone depth corresponding to the second geophone point.

[0080] Indicative, such as Figure 5 As shown, the computer device determines the formation depth of candidate formation Q1 based on the first detector point depth corresponding to the first detector point 5021 of the first detector and the second detector point depth corresponding to the second detector point 5022 of the second detector.

[0081] In one possible implementation, a computer device determines the formation depth of a candidate formation based on the first excitation point depth of a first excitation point and the second excitation point depth of a second excitation point.

[0082] Indicative, such as Figure 8 As shown, when the first excitation point 8011 and the second excitation point 8012 in the excitation well 801 are respectively shot point excitation to generate seismic waves, the computer equipment acquires the seismic waves received by the first detector at the first detector point 8021 in the receiving well 802, and determines the formation depth of candidate formation Q1 based on the first excitation point depth of the first excitation point 8011 and the second excitation point depth of the second excitation point 8012.

[0083] Step 405: Based on the receiving frequency and propagation time of the seismic wavelet, determine the layer Q value corresponding to the formation depth using the peak frequency shift formula.

[0084] In one possible implementation, the computer device determines the layer Q value corresponding to the formation depth using the peak frequency shift formula, based on the propagation duration and received frequency data of two sets of seismic wavelets.

[0085]

[0086] Among them, t n This refers to the propagation time of a seismic wavelet with a longer propagation path, t. n+1 This refers to the propagation time of seismic wavelets with shorter propagation paths, f. n This refers to the receiving frequency of seismic wavelets with longer propagation paths, f. n+1 This refers to the receiving frequency of seismic wavelets with shorter propagation paths.

[0087] In one possible implementation, the computer device determines the layer Q value corresponding to the formation depth using a peak frequency shift formula based on the first propagation time of the first seismic wavelet, the first receiving frequency of the first seismic wavelet, the second propagation time of the second seismic wavelet, and the second receiving frequency of the second seismic wavelet. The first seismic wavelet is intercepted from the first seismic wave received by the first detector, and the second seismic wavelet is intercepted from the second seismic wave received by the second detector. The first and second seismic waves are generated from the same excitation point.

[0088] Indicative, such as Figure 5 As shown, the first propagation time of the first seismic wavelet is t1, the first receiving frequency of the first seismic wavelet is f1, the second propagation time of the second seismic wavelet is t2, and the second receiving frequency of the second seismic wavelet is f2. The computer equipment can determine the layer Q value corresponding to the depth of candidate stratum Q1 using the peak frequency shift formula.

[0089]

[0090] In one possible implementation, the computer device determines the layer Q value corresponding to the formation depth using a peak frequency shift formula based on the third propagation time of the third seismic wavelet, the third receiving frequency of the third seismic wavelet, the fourth propagation time of the fourth seismic wavelet, and the fourth receiving frequency of the fourth seismic wavelet. The third seismic wavelet is intercepted from the third seismic wave received by the target geophone, and the fourth seismic wavelet is intercepted from the fourth seismic wave received by the target geophone. The third seismic wave is generated by the first excitation point, and the fourth seismic wave is generated by the second excitation point.

[0091] Indicative, such as Figure 8 As shown, the third propagation time of the third seismic wavelet is t3, the third receiving frequency of the third seismic wavelet is f3, the fourth propagation time of the fourth seismic wavelet is t4, and the fourth receiving frequency of the fourth seismic wavelet is f4. The computer equipment can determine the layer Q value corresponding to the formation depth of candidate stratum Q1 using the peak frequency shift formula.

[0092]

[0093] Step 406: Perform tomographic inversion based on micrologging information to obtain the near-surface velocity field.

[0094] In one possible implementation, a computer device obtains the near-surface velocity field based on micrologging information through tomographic inversion. First, the computer device determines an initial velocity model based on the micrologging information, including formation conditions and geological structure. Then, it simulates ray paths in the initial model grid using the shortest path ray tracing method to calculate the travel time of the first-arrival seismic wave. This travel time is compared with the actual acquired first-arrival seismic wave travel time to establish a linear equation for travel time inversion. This equation is then used to correct and iteratively update the initial velocity model, resulting in a more accurate near-surface velocity field.

[0095] Step 407: Based on the correspondence between the Q values ​​of different candidate strata and the stratum depth, as well as the near-surface velocity field, the QV scale is obtained by fitting using the least squares method.

[0096] In one possible implementation, in order to obtain a relatively accurate correspondence between layer Q values ​​and formation velocities, a computer device fits the relationship between layer Q values ​​and formation velocities using the least squares method based on the correspondence between layer Q values ​​and formation depth for different candidate formations, as well as the near-surface velocity field, thereby obtaining a QV scale, i.e., a QV relationship curve, which reflects a continuous correspondence between layer Q values ​​and formation velocities.

[0097] Step 408: Construct the near-surface Q field based on the QV scale and the near-surface velocity field.

[0098] Step 409: Perform near-surface Q-compensation processing based on the near-surface Q-field.

[0099] The implementation methods for steps 408 and 409 can refer to steps 204 and 205 above, and will not be repeated here in this embodiment.

[0100] In the above embodiments, the computer device calculates the layer Q value based on the first and second seismic waves generated from the same excitation point, or the third and fourth seismic waves generated from different excitation points received by the same detector, using the peak frequency shift formula. This improves the accuracy of the layer Q value calculation. Furthermore, through tomographic inversion, the initial velocity model can be corrected and iteratively updated to obtain a more accurate near-surface velocity field, thus improving the accuracy of the near-surface Q field construction.

[0101] Since there are various ways to divide candidate strata, there may be issues of overlapping or covering of candidate strata, and the same candidate stratum may also have multiple corresponding layer Q values. Therefore, in order to obtain a clearer stratigraphic division and a more accurate QV fitting relationship, it is necessary to screen the received seismic waves and screen multiple layer Q values ​​of the same candidate stratum. The process is described in detail below.

[0102] Please refer to Figure 9This illustrates a flowchart of a near-surface Q-compensation method provided in another exemplary embodiment of this application. The method may include the following steps:

[0103] Step 901: Obtain the seismic waves received by the geophones in the receiving well. The receiving well is equipped with at least three geophones, which are located at geophone points at different depths in the receiving well. The seismic waves are generated by the excitation points in the excitation well, and different excitation points are located at different depths in the excitation well.

[0104] The implementation method of this step can refer to step 201 above, and will not be repeated here.

[0105] Step 902: Determine the excitation point depth of the excitation point and the detection point depth of each detector corresponding to the detection point. Select candidate detectors from the detectors. The depth difference between the candidate detector and the excitation point is smaller than the depth difference between other detectors and the excitation point.

[0106] Because seismic waves attenuate during propagation through the strata, for seismic waves generated from the same excitation point, the seismic waves received by detectors closer to the excitation point have a smaller attenuation amplitude and a more complete waveform, while the seismic waves received by detectors farther from the excitation point have a larger attenuation amplitude and a more obvious waveform change. Therefore, in order to improve the accuracy of seismic wave data and reduce the storage of invalid data, based on the excitation point depth of different excitation points, the computer equipment selects candidate detectors corresponding to different excitation points from the detectors.

[0107] In one possible implementation, the computer device determines the excitation depth of the excitation point and the detection point depth of the corresponding detection point of each detector, and selects candidate detectors from the detectors based on the depth difference between the excitation point and the detector, so that the depth difference between the candidate detector and the excitation point is smaller than the depth difference between other detectors and the excitation point.

[0108] Optionally, the number of candidate detectors is at least two, depending on the calculation of the layer Q value. When the depth differences are relatively small, the number of candidate detectors can also be multiple.

[0109] Indicative, such as Figure 10 As shown, when a shot point is generated at the third excitation point 1013 in the excitation well 1010 to produce a seismic wave, the geophones at the first geophone point 1021, the second geophone point 1022, the third geophone point 1023, the fourth geophone point 1024, and the fifth geophone point 1025 in the receiving well 1020 can all receive the seismic wave. Due to the depth difference between each geophone and the third excitation point 1013, the computer equipment can select the geophones at the second geophone point 1022, the third geophone point 1023, and the fourth geophone point 1024 as candidate geophones.

[0110] Step 903: Filter the seismic waves received by the candidate detectors.

[0111] In one possible implementation, in order to obtain a more complete seismic wave waveform, the computer device filters the seismic waves received by each candidate detector, thereby obtaining more accurate seismic wave data.

[0112] Step 904: Determine the layer Q value of different candidate strata based on the receiving frequency and propagation time of the seismic waves received by the candidate detectors.

[0113] Furthermore, based on the receiving frequency and propagation time of the seismic waves received by the candidate detectors, the computer equipment determines the layer Q value of different candidate strata.

[0114] Step 905: Perform outlier filtering on multiple layer Q values ​​corresponding to the same candidate stratum.

[0115] In one possible implementation, based on the seismic wave data received by each detector, multiple layer Q values ​​can be calculated for the same candidate stratum due to the variability of excitation and reception conditions. Therefore, there may be obvious outliers in the calculated layer Q values, so the computer equipment needs to perform outlier filtering on the multiple layer Q values ​​corresponding to the same candidate stratum.

[0116] Indicative, such as Figure 11 As shown, when a shot point 1111 in the excitation well 1110 is used to generate seismic waves, the geophones at the first geophone point 1121 and the second geophone point 1122 in the receiving well 1120 receive the seismic waves; similarly, when a shot point 1112 in the excitation well 1110 is used to generate seismic waves, the geophones at the first geophone point 1121 and the second geophone point 1122 in the receiving well 1120 receive the seismic waves. Therefore, for candidate formation Q1, the computer equipment can determine the seismic waves based on the signals received by the geophones at the first geophone point 1121 and the second geophone point 1122. The seismic wave data generated by the first excitation point 1111, or the seismic wave data generated by the second excitation point 1112 received by the detectors at the first and second detector points 1121, or the seismic wave data generated by the first excitation point 1111 and the second excitation point 1112 received by the detector at the first detector point 1121, or the seismic wave data generated by the first excitation point 1111 and the second excitation point 1112 received by the detector at the second detector point 1122, are used to calculate the four layer Q values ​​corresponding to the candidate stratum Q1, and then the computer equipment performs outlier filtering on the four layer Q values.

[0117] Step 906: Based on the filtered layer Q-values, determine the target layer Q-values ​​of the candidate formations.

[0118] In one possible implementation, after filtering out anomalous layer Q values, there may be multiple similar layer Q values ​​for the same candidate formation, so the computer device can determine the target layer Q value of the candidate formation from the multiple layer Q values ​​by calculating the average value.

[0119] Step 907: Based on the target layer Q value, formation depth, and near-surface velocity field of different candidate strata, the QV scale is fitted to obtain the QV scale.

[0120] Furthermore, based on the target layer Q value, formation depth, and near-surface velocity field corresponding to different candidate formations, the computer equipment fits and obtains the QV scale.

[0121] Step 908: Construct the near-surface Q field based on the QV scale and the near-surface velocity field.

[0122] Step 909: Perform near-surface Q-compensation processing based on the near-surface Q-field.

[0123] The implementation methods for steps 908 and 909 can refer to steps 204 and 205 above, and will not be repeated here in this embodiment.

[0124] In the above embodiments, the computer device determines candidate detectors from multiple detectors based on the depth difference between the detector and the excitation point, reducing the storage and calculation of invalid seismic wave data. In addition, for multiple layer Q values ​​of the same candidate stratum, the computer device determines the target layer Q value through outlier filtering, improving the accuracy of the layer Q value of the candidate stratum.

[0125] Please refer to Figure 12 The figure shows a schematic diagram of the near-surface Q-field provided in an exemplary embodiment of this application. As shown, the near-surface Q-field characterizes the correspondence between the formation depth and the layer Q value.

[0126] Please refer to Figure 13 The diagram illustrates a structural block diagram of a near-surface Q-compensation device provided in an exemplary embodiment of this application. The device may include the following structure:

[0127] The seismic wave acquisition module 1301 is used to acquire seismic waves received by the detectors in the receiving well. The receiving well is equipped with at least three detectors, and the at least three detectors are located at detector points at different depths in the receiving well. The seismic waves are generated by excitation points in the excitation well, and different excitation points are located at different depths in the excitation well.

[0128] Q-value determination module 1302 is used to determine the layer Q-value of different candidate strata based on the receiving frequency and propagation time of the seismic waves, wherein the different candidate strata are located at different stratum depths.

[0129] The QV scale fitting module 1303 is used to fit a QV scale based on the layer Q value, the layer depth and the near-surface velocity field of different candidate strata. The near-surface velocity field is used to characterize the relationship between the layer depth and the layer velocity. The QV scale is used to characterize the relationship between the layer Q value and the layer velocity.

[0130] Q-field construction module 1304 is used to construct a near-surface Q-field based on the QV scale and the near-surface velocity field.

[0131] The Q-value compensation module 1305 is used to perform near-surface Q-compensation processing based on the near-surface Q-field.

[0132] Optionally, the Q-value determination module 1302 includes:

[0133] The wavelet truncation unit is used to truncate the seismic wave received by the detector to obtain a seismic wavelet, wherein the seismic wavelet is a complete waveform segment of the first arrival seismic wave.

[0134] A spectrum analysis unit is used to perform spectrum analysis on the seismic wavelet to obtain the receiving frequency of the seismic wavelet;

[0135] A depth determination unit is used to determine the formation depth of the candidate formation based on the detector point depth of the detector corresponding to the detector point, or the excitation point depth of the excitation point.

[0136] The Q-value determination unit is used to determine the layer Q-value corresponding to the formation depth based on the receiving frequency and propagation duration of the seismic wavelet using the peak frequency shift formula.

[0137] Optionally, the depth determination unit is used for:

[0138] The formation depth of the candidate formation is determined based on the first detector point depth corresponding to the first detector point and the second detector point depth corresponding to the second detector point.

[0139] The Q-value determination unit is used for:

[0140] Based on the first propagation time of the first seismic wavelet, the first receiving frequency of the first seismic wavelet, the second propagation time of the second seismic wavelet, and the second receiving frequency of the second seismic wavelet, the layer Q value corresponding to the formation depth is determined by the peak frequency shift formula. The first seismic wavelet is intercepted from the first seismic wave received by the first detector, and the second seismic wavelet is intercepted from the second seismic wave received by the second detector. The first seismic wave and the second seismic wave are generated from the same excitation point.

[0141] Optionally, the depth determination unit is used for:

[0142] The formation depth of the candidate formation is determined based on the first excitation point depth of the first excitation point and the second excitation point depth of the second excitation point.

[0143] The Q-value determination unit is used for:

[0144] Based on the third propagation time of the third seismic wavelet, the third receiving frequency of the third seismic wavelet, the fourth propagation time of the fourth seismic wavelet, and the fourth receiving frequency of the fourth seismic wavelet, the layer Q value corresponding to the formation depth is determined by the peak frequency shift formula. The third seismic wavelet is intercepted from the third seismic wave received by the target geophone, and the fourth seismic wavelet is intercepted from the fourth seismic wave received by the target geophone. The third seismic wave is generated by the first excitation point, and the fourth seismic wave is generated by the second excitation point.

[0145] Optionally, the QV measurement module 1303 is used for:

[0146] The near-surface velocity field is obtained by tomographic inversion based on micrologging information;

[0147] Based on the correspondence between the Q value of different candidate strata and the stratum depth, and the near-surface velocity field, the QV scale is obtained by least squares fitting.

[0148] Optionally, before determining the layer Q value of different candidate strata based on the received frequency and propagation time of the seismic waves, the device further includes:

[0149] The depth determination module is used to determine the excitation point depth of the excitation point and the detector point depth of each detector corresponding to the detector point, and to select candidate detectors from the detectors, wherein the depth difference between the candidate detector and the excitation point is smaller than the depth difference between other detectors and the excitation point;

[0150] A seismic wave filtering module is used to filter the seismic waves received by the candidate detectors;

[0151] The Q-value determination module 1302 is used for:

[0152] The layer Q value of different candidate strata is determined based on the receiving frequency and propagation time of the seismic waves received by the candidate geophones.

[0153] Optionally, when multiple layer Q values ​​corresponding to the same candidate stratum are determined, before fitting the QV scale based on the layer Q values, stratum depth, and near-surface velocity field of different candidate strata, the device further includes:

[0154] The Q-value processing module is used to perform outlier filtering on multiple Q-values ​​corresponding to the same candidate stratum.

[0155] The Q-value determination module 1302 is used to determine the target layer Q-value of the candidate stratum based on the filtered layer Q-value;

[0156] The QV measurement module 1303 is used for:

[0157] The QV scale is obtained by fitting the target layer Q value, the layer depth, and the near-surface velocity field based on different candidate strata.

[0158] In summary, in this embodiment, by acquiring seismic waves received by at least three geophones at different depths in the receiving well, the layer Q values ​​of different candidate strata can be determined based on the received seismic wave frequency and propagation time. Furthermore, based on the obtained layer Q values, stratum depth, and near-surface velocity field of different candidate strata, a QV scale is fitted, and a near-surface Q field is constructed based on the QV scale and the near-surface velocity field. Finally, near-surface Q compensation processing is performed based on the near-surface Q field. Using the scheme provided in this embodiment, by setting at least three geophones at different depths in the receiving well, multiple layers of Q values ​​can be obtained based on the seismic wave data received by the geophones, improving the accuracy of Q value estimation. Moreover, by fitting the QV scale, the near-surface Q field can be obtained by fitting the near-surface velocity field, further improving the accuracy of the near-surface Q field.

[0159] It should be noted that the apparatus provided in the above embodiments is only an example of the division of the above functional modules. In practical applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the apparatus can be divided into different functional modules to complete all or part of the functions described above. In addition, the apparatus and method embodiments provided in the above embodiments belong to the same concept, and their implementation process can be found in the method embodiments, which will not be repeated here.

[0160] Please refer to Figure 14 This diagram illustrates a structural block diagram of a computer device provided in an exemplary embodiment of this application. The computer device 1400 may include one or more components such as a processor 1410 and a memory 1420.

[0161] Processor 1410 may include one or more processing cores. Processor 1410 connects to various parts within the computer device 1400 using various interfaces and lines, and performs various functions and processes data of the computer device 1400 by running or executing instructions, programs, code sets, or instruction sets stored in memory 1420, and by calling data stored in memory 1420. Optionally, processor 1410 may be implemented using at least one hardware form of Digital Signal Processing (DSP), Field-Programmable Gate Array (FPGA), or Programmable Logic Array (PLA). Processor 1410 may integrate one or more of the following: Central Processing Unit (CPU), Graphics Processing Unit (GPU), Neural-network Processing Unit (NPU), and modem. Specifically, the CPU primarily handles the operating system, user interface, and applications; the GPU is responsible for rendering and drawing the content required to be displayed on the touch screen; the NPU is used to implement Artificial Intelligence (AI) functions; and the modem is used to handle wireless communication. It is understandable that the aforementioned modem may not be integrated into the processor 1410, but may be implemented as a separate chip.

[0162] The memory 1420 may include random access memory (RAM) or read-only memory (ROM). Optionally, the memory 1420 may include a non-transitory computer-readable storage medium. The memory 1420 may be used to store instructions, programs, code, code sets, or instruction sets. The memory 1420 may include a program storage area and a data storage area, wherein the program storage area may store instructions for implementing an operating system, instructions for at least one function (such as touch function, sound playback function, image playback function, etc.), instructions for implementing the various method embodiments described below, etc.; the data storage area may store data (such as audio data, telephone book, etc.) created according to the use of the computer device 1400.

[0163] In addition, those skilled in the art will understand that the structure of the computer device 1400 shown in the above figures does not constitute a limitation on the computer device. The computer device may include more or fewer components than shown, or combine certain components, or have different component arrangements. For example, the computer device 1400 also includes a display screen, camera, microphone, speaker, radio frequency circuit, input unit, sensors (such as accelerometer, angular velocity sensor, light sensor, etc.), audio circuit, WiFi module, power supply, Bluetooth module, etc., which will not be described in detail here.

[0164] This application also provides a computer-readable storage medium storing at least one piece of program code, which is loaded and executed by a processor to implement the near-surface Q-compensation method as described in the above embodiments.

[0165] It should be understood that "multiple" as used herein refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. Furthermore, the step numbers described herein are merely illustrative of one possible execution order. In some other embodiments, the steps may not be executed in numerical order, such as two steps with different numbers being executed simultaneously, or two steps with different numbers being executed in the reverse order of the illustration. This application does not limit this.

[0166] The above description is merely an optional embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A near-surface Q compensation method, characterized in that, The method includes: The seismic wave received by the geophone in the receiving well is acquired. The receiving well is equipped with at least three geophones, and the at least three geophones are located at geophone points at different depths in the receiving well. The seismic wave is generated by the excitation point in the excitation well, and different excitation points are set at different depths in the excitation well. Determine the excitation point depth of the excitation point and the detection point depth of each detector corresponding to the detection point, and select candidate detectors from the detectors, wherein the depth difference between the candidate detector and the excitation point is smaller than the depth difference between other detectors and the excitation point; The seismic waves received by the candidate detectors are filtered; The seismic waves received by the candidate geophones are truncated into a wavelet to obtain a seismic wavelet, which is a complete waveform segment of the first arrival seismic wave; the seismic wavelet is subjected to spectral analysis to obtain the received frequency of the seismic wavelet; based on the received frequency and propagation time of the seismic wavelet, the layer Q value of different candidate strata is determined by the peak frequency shift formula, wherein the different candidate strata are located at different stratum depths; Based on the layer Q value, layer depth, and near-surface velocity field of different candidate strata, a QV scale is obtained by fitting. The near-surface velocity field is used to characterize the relationship between layer depth and layer velocity. The QV scale is used to characterize the relationship between layer Q value and layer velocity. Construct a near-surface Q-field based on the QV scale and the near-surface velocity field; Near-surface Q-compensation processing is performed based on the near-surface Q-field.

2. The method according to claim 1, characterized in that, The method further includes: The formation depth of the candidate formation is determined based on the detector point depth corresponding to the detector point, or the excitation point depth of the excitation point.

3. The method according to claim 2, characterized in that, Determining the formation depth of the candidate formation based on the detector point depth corresponding to the detector point, or the excitation point depth of the excitation point, includes: The formation depth of the candidate formation is determined based on the first detector point depth corresponding to the first detector point and the second detector point depth corresponding to the second detector point. The method further includes: Based on the first propagation time of the first seismic wavelet, the first receiving frequency of the first seismic wavelet, the second propagation time of the second seismic wavelet, and the second receiving frequency of the second seismic wavelet, the layer Q value corresponding to the formation depth is determined by the peak frequency shift formula. The first seismic wavelet is intercepted from the first seismic wave received by the first detector, and the second seismic wavelet is intercepted from the second seismic wave received by the second detector. The first seismic wave and the second seismic wave are generated from the same excitation point.

4. The method according to claim 2, characterized in that, Determining the formation depth of the candidate formation based on the detector point depth corresponding to the detector point, or the excitation point depth of the excitation point, includes: The formation depth of the candidate formation is determined based on the first excitation point depth of the first excitation point and the second excitation point depth of the second excitation point. The method further includes: Based on the third propagation time of the third seismic wavelet, the third receiving frequency of the third seismic wavelet, the fourth propagation time of the fourth seismic wavelet, and the fourth receiving frequency of the fourth seismic wavelet, the layer Q value corresponding to the formation depth is determined by the peak frequency shift formula. The third seismic wavelet is intercepted from the third seismic wave received by the target geophone, and the fourth seismic wavelet is intercepted from the fourth seismic wave received by the target geophone. The third seismic wave is generated by the first excitation point, and the fourth seismic wave is generated by the second excitation point.

5. The method according to any one of claims 1 to 4, characterized in that, The QV scale is obtained by fitting the layer Q value, the layer depth, and the near-surface velocity field based on different candidate strata, including: The near-surface velocity field is obtained by tomographic inversion based on micrologging information; Based on the correspondence between the Q value of different candidate strata and the stratum depth, and the near-surface velocity field, the QV scale is obtained by least squares fitting.

6. The method according to any one of claims 1 to 4, characterized in that, When multiple layer Q values ​​corresponding to the same candidate stratum are determined, before fitting the QV scale based on the layer Q values, stratum depth, and near-surface velocity field of different candidate strata, the method further includes: Outlier filtering is performed on multiple Q values ​​corresponding to the same candidate stratum. Based on the filtered layer Q value, the target layer Q value of the candidate strata is determined; The QV scale is obtained by fitting the layer Q value, the layer depth, and the near-surface velocity field based on different candidate strata, including: The QV scale is obtained by fitting the target layer Q value, the layer depth, and the near-surface velocity field based on different candidate strata.

7. A near-surface Q-compensation device, characterized in that, The device includes: A seismic wave acquisition module is used to acquire seismic waves received by detectors in a receiving well. The receiving well is equipped with at least three detectors, which are located at different depths in the receiving well. The seismic waves are generated by excitation points in an excitation well, and different excitation points are located at different depths in the excitation well. The depth determination module is used to determine the excitation point depth of the excitation point and the detector point depth of each detector corresponding to the detector point, and to select candidate detectors from the detectors, wherein the depth difference between the candidate detector and the excitation point is smaller than the depth difference between other detectors and the excitation point; A seismic wave filtering module is used to filter the seismic waves received by the candidate detectors; The Q-value determination module is used to extract wavelet segments from the seismic waves received by the candidate detectors to obtain seismic wavelets, wherein the seismic wavelets are a complete waveform segment of the first arrival seismic waves; to perform spectral analysis on the seismic wavelets to obtain the received frequency of the seismic wavelets; and to determine the layer Q-values ​​of different candidate strata using the peak frequency shift formula based on the received frequency and propagation duration of the seismic wavelets, wherein the different candidate strata are located at different stratum depths. The QV scale fitting module is used to fit a QV scale based on the layer Q value, the layer depth, and the near-surface velocity field of different candidate strata. The near-surface velocity field is used to characterize the relationship between the layer depth and the layer velocity, and the QV scale is used to characterize the relationship between the layer Q value and the layer velocity. The Q-field construction module is used to construct the near-surface Q-field based on the QV scale and the near-surface velocity field. The Q-value compensation module is used to perform near-surface Q-compensation processing based on the near-surface Q-field.

8. A computer device, characterized in that, The computer device includes a processor and a memory; the memory stores at least one instruction, which is executed by the processor to implement the near-surface Q-compensation method as described in any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores at least one piece of program code, which is loaded and executed by a processor to implement the near-surface Q-compensation method as described in any one of claims 1 to 6.

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