Interlayer multiple suppression method, system, equipment and medium

Abstract

The invention belongs to the field of oil-gas exploration, and relates to an interlayer multiple suppression method, system and device and a medium. The method comprises the following steps: acquiring actual profile data; and data above the strong reflection layer in the actual profile data are cut off to obtain cut-off profile data, so that the cut-off profile data meet the requirements of 0D-SRME. The 0D-SRME is combined with the cut profile data for prediction to obtain the predicted multiples, and the prediction precision of the multiples is high. And adaptively subtracting the predicted multiples from the actual profile data by using a least square method to obtain profile data without the multiples. By applying 0D-SRME, multiples and interlayer multiples are effectively suppressed and eliminated, effective signals of seismic data are recovered, counterfeit removal and true storage are achieved, the imaging quality of a land ultra-deep seismic section is scientifically and reasonably improved, the multiple prediction precision is high, the suppression effect is good, the seismic imaging reliability is improved, and true underground geological information is more accurately provided.

Description

Technical Field

[0001] The invention belongs to the field of oil and gas exploration and relates to an interlayer multiple wave suppression method, system, equipment and medium. Background Art

[0002] Strong sand layers are also good reflection interfaces, so seismic waves can easily oscillate back and forth between the diving surface and the strong sand layers, forming strong multiple wave interference. In addition, seismic waves will also form interlayer multiple waves between several sets of strong reflection interfaces in the ultra-deep target layer on land. These multiple waves related to the free surface, interlayer multiple waves and effective waves are mixed together, which will reduce the profile resolution and seriously affect the authenticity and reliability of seismic imaging.

[0003] In desert areas, there are many methods for suppressing interlayer multiple waves, such as predictive deconvolution technology, traditional fk, Radon transform, 3D-SRME technology, etc.

[0004] In practical applications, predictive deconvolution technology can only compress wavelets to a limited extent and improve resolution, but has limited effect on attenuation of multiple waves. Traditional fk filtering and Radon transform multiple wave suppression methods are limited by their ability to transform and distinguish events based on different time differences, especially for interlayer multiple waves that are very similar to reflection signals, which are basically impossible to remove using these methods. Traditional 3D-SRME has a relatively good effect on marine data. This method is based on a single regular acquisition condition because the distribution of shots and checkpoints in the marine seismic data acquisition system has its regularity. However, the shots and checkpoints of desert surface seismic data are often irregular and do not meet the prerequisites of 3D-SRME. In addition, the signal-to-noise ratio of the data is low, which leads to wrong multiple wave prediction operators and affects the effect of interlayer multiple wave suppression. Summary of the invention

[0005] In order to overcome the shortcomings of the above-mentioned prior art, the purpose of the present invention is to provide a method, system, equipment and medium for suppressing interlayer multiple waves. The present invention adopts 0D-SRME to suppress interlayer multiple waves, and the multiple wave prediction accuracy is high, the suppression effect is good, and the reliability of seismic imaging is improved.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] In a first aspect, the present invention discloses a method for suppressing interlayer multiple waves, comprising the following steps:

[0008] Obtain actual profile data;

[0009] Cut off the data above the strong reflection layer in the actual profile data to obtain the profile data after cutting off;

[0010] The predicted multiple waves were obtained by using 0D-SRME combined with the section data after resection;

[0011] The predicted multiple waves are adaptively subtracted from the actual profile data using the least squares method to obtain profile data with multiple waves eliminated.

[0012] In a second aspect, according to the method of the present invention, an interlayer multiple wave suppression system is provided, characterized in that it comprises: a data acquisition module, a data removal module, a multiple wave prediction module and a multiple wave elimination module;

[0013] Data acquisition module: used to obtain actual profile data;

[0014] Data removal module: used to remove the data above the strong reflection layer in the actual profile data to obtain the profile data after removal;

[0015] Multiple wave prediction module: used to predict the predicted multiple waves by using 0D-SRME combined with the section data after resection;

[0016] Multiple wave elimination module: It is used to adaptively subtract the predicted multiple waves from the actual profile data using the least squares method to obtain the profile data with the multiple waves eliminated.

[0017] In a third aspect, the present invention provides an electronic device, comprising: a processor; a memory for storing computer program instructions; and steps for implementing a method for automatically synchronizing historical data with a real-time database when executing the computer program.

[0018] In a fourth aspect, the present invention provides a storage medium storing computer program instructions. When the computer program instructions are loaded and executed by a processor, the processor executes a method for automatically synchronizing historical data with a real-time database.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] The method of the present invention: obtain actual profile data. The data above the strong reflection layer in the actual profile data is cut off to obtain the profile data after the cut off, so as to achieve an effect similar to the seabed reflection, so that the profile data after the cut off meets the requirements of 0D-SRME. 0D-SRME is used in combination with the profile data after the cut off to predict the predicted multiple waves, and the prediction accuracy of the multiple waves is high. The predicted multiple waves are adaptively subtracted from the actual profile data using the least squares method to obtain the profile data with the multiple waves eliminated. The amplitude and phase deviation of the predicted multiple waves are corrected by the least squares method adaptive subtraction, so as to ensure the elimination of multiple waves of the seismic data. By applying 0D-SRME to effectively suppress and eliminate multiple waves and interlayer multiple waves, the effective signal of the seismic data is restored, the false is eliminated and the true is retained, and the imaging quality of the ultra-deep seismic profile on land is scientifically and rationally improved, the multiple wave prediction accuracy is high, the suppression effect is good, the reliability of seismic imaging is improved, and the real underground geological information is provided more accurately.

[0021] The system of the present invention includes a data acquisition module, a data excision module, a multiple wave prediction module and a multiple wave elimination module. The data acquisition module is used to acquire actual profile data. The data excision module is used to excise the data above the strong reflection layer in the actual profile data to obtain the profile data after excision. The multiple wave prediction module is used to use 0D-SRME combined with the profile data after excision to predict and obtain predicted multiple waves. The multiple wave elimination module is used to use the least squares method to adaptively subtract the predicted multiple waves from the actual profile data to obtain the profile data with the multiple waves eliminated. The modules cooperate with each other to effectively suppress the multiple waves between layers, the multiple wave prediction accuracy is high, the suppression effect is good, and the reliability of seismic imaging is improved.

[0022] The electronic device and storage medium provided by the present invention can also effectively suppress interlayer multiple waves, with high multiple wave prediction accuracy and good suppression effect, thereby improving the reliability of seismic imaging. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a schematic diagram of a zero-offset 0D-SRME of the present invention;

[0024] Figure 2 The convolution of a zero-offset primary wave and a secondary wave with its own primary wave will produce a secondary wave and a cubic wave flow chart;

[0025] Figure 3 The convolution of a zero-offset primary and secondary wave with itself will produce a secondary wave, a cubic wave, and a quartic wave;

[0026] Figure 4 It is a 2D velocity model diagram;

[0027] Figure 5This is a schematic diagram of multiple wave suppression of CMP stacking data of velocity model 1;

[0028] Figure 6 This is a schematic diagram of multiple wave suppression in prestack time migration of model data 1;

[0029] Figure 7 This is a schematic diagram of multiple wave suppression in the stacked section of the Sigsbee model;

[0030] Figure 8 This is a schematic diagram of multiple wave suppression of reverse time migration data of the Sigsbee model;

[0031] Fig. 9 This is the multiple wave suppression effect diagram of the Sigsbee model reverse time migration data;

[0032] Fig.10 It is the Ronan 3D actual pre-stack time migration profile and the profile after multiple wave suppression;

[0033] Fig.11 The present invention is applied to Fig.10 Multiple wave profiles predicted from the data;

[0034] Fig.12 is a flow chart of the method of the present invention;

[0035] Fig.13 It is a system structure diagram of the present invention. DETAILED DESCRIPTION

[0036] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0037] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0038] The present invention is further described in detail below in conjunction with the accompanying drawings:

[0039] See also Fig.12 The present invention discloses an interlayer multiple wave suppression method, comprising the following steps:

[0040] S1. Obtain actual profile data;

[0041] The actual profile data needs to be preprocessed. The actual profile data is preprocessed to the profile after CMP gather stacking or migration is completed.

[0042] S2. cutting off the data above the strong reflection layer in the actual profile data to obtain the profile data after cutting off;

[0043] When cutting off the data above the strong reflection layer in the actual profile data, the cutting should be performed along the reflection layer.

[0044] S3. Use 0D-SRME combined with the resected profile data to predict the predicted multiple waves;

[0045] The details are as follows:

[0046] Each section data after resection is divided into at least one time window, at least one matched filter is performed in each time window to obtain a matched filter operator, and then 0D-SRME combined with the filter operator is used for prediction to obtain the predicted multiple waves.

[0047] 0D-SRME is as follows:

[0048] P(z0)=D - (z0)X0(z0,z0)[S + (z0)+R - (z0)P - (z0)]=P0(z0)+M0(z0)

[0049] P0(z0)=D - (z0)X0(z0,z0)S + (z0)

[0050] M0(z0)=D - (z0)X0(z0,z0)[R - (z0)P - (z0)]

[0051] Among them, P(z0) is the single reflection wave, M0(z0) is the multiple reflection wave; X0(z0, z0) is the underground propagation operator without interlayer multiple waves, R - is the reflection operator of the upgoing wave, S + (z0) is the source wave field at the sea surface z0, D- (z0) is the receiver operator, P - (z0) is the upgoing wave field.

[0052] X0(z0, z0) is as follows:

[0053]

[0054] Among them, R + is the reflection operator of the downlink wave, W - is the propagation operator of the upgoing wave, W + is the propagation operator of the downlink wave.

[0055] P - (z0) The details are as follows:

[0056] If interlayer multiple waves are ignored, P - (z0) is:

[0057]

[0058] If all multiples are neglected, P - (z0) is:

[0059]

[0060] Among them, P + (z0) is the downlink wave field.

[0061] S4. Use the least square method to adaptively subtract the predicted multiple waves from the actual profile data to obtain the profile data with the multiple waves eliminated.

[0062] See also Fig.12In another feasible embodiment of the present invention, the following is adaptively modified according to the situation. Acquire actual profile data. Cut the data above the strong reflection layer in the actual profile data to obtain the profile data after cutting, so as to achieve an effect similar to the seabed reflection, so that the profile data after cutting meets the requirements of 0D-SRME. Use 0D-SRME combined with the profile data after cutting to predict the predicted multiple waves, and the prediction accuracy of the multiple waves is high. Use the least squares method to adaptively subtract the predicted multiple waves from the actual profile data to obtain the profile data with the multiple waves eliminated. Since the reflection coefficients of the formations with different amplitudes are averaged after the stacking process, the amplitude of the predicted multiple waves that are inconsistent with the expected amplitude will increase, and the phase will also deviate during the stacking process. Therefore, the least squares method is used for adaptive subtraction to correct the amplitude and phase deviation of the predicted multiple waves, thereby ensuring the elimination of multiple waves in the seismic data. By applying 0D-SRME to effectively suppress and eliminate multiple waves and interlayer multiple waves, the effective signals of seismic data can be restored, the true signals can be retained while the false signals can be eliminated, and the imaging quality of ultra-deep seismic profiles on land can be improved scientifically and rationally. The multiple wave prediction accuracy is high and the suppression effect is good, which improves the reliability of seismic imaging and provides more accurate and real underground geological information.

[0063] Embodiment 1:

[0064] The theory of 0D-SRME is as follows:

[0065] The present invention proposes a method for suppressing multiple waves between layers, specifically, a method for suppressing multiple waves between layers of 0D-SRME target layers. This theory is also based on the propagation theory of seismic longitudinal waves or p waves, and a method for suppressing multiple waves based on the wave equation. The forward model of the seismic wave field can be described by the following formula:

[0066]

[0067] P + (z m, z0)=W + (z m, z m-1 )[P + (z m-1, z0)+R - (z m-1 ) - (z m-1, z0)](1b)

[0068] P + (z0) = S + (z0)+R - (z0)P - (z0)(1c)(1c)

[0069] Here P- is the upgoing wave field, P + is the downlink wave field, W - is the propagation operator of the upgoing wave, W + is the propagation operator of the downlink wave, R - is the reflection operator of the upgoing wave, R + is the reflection operator of the downlink wave, S + (z0) is the source wave field at the sea surface z0. If it is a continuous function, Formula 1a, Formula 1b and Formula 1c are integral processes; if it is a discrete function, Formula 1a, Formula 1b and Formula 1c are matrix operations. Formula 1a, Formula 1b and Formula 1c are Fourier transforms or Laplace transforms of a time point, which are applicable to two-dimensional wave fields as well as three-dimensional wave fields.

[0070] If interlayer multiple waves are ignored, Equations 1a and 1b can be simplified to

[0071]

[0072] If all multiple waves are neglected, Equation 1a and Equation 1b can be simplified to

[0073]

[0074] If you define

[0075]

[0076] Then X0(z 0, z0) is the underground propagation operator without interlayer multiple waves

[0077] If you use D - (z0) represents the receiver operator. The wave field recorded at the receiving point is:

[0078] P(z0)=D - (z0)X0(z 0, z0)[S + (z0)+R - (z0)P - (z0)]=P0(z0)+M0(z0) (3)

[0079] Among them, P(z0) is the single reflection wave, and M0(z0) is the multiple reflection wave.

[0080] P0(z0)=D - (z0)X0(z 0, z0)S + (z0) (4)

[0081] M0(z0)=D - (z0)X0(z0, z00[R - (z0)P - (z0)] (5)

[0082] The task of SRME is to predict the multiple waves M0(z0) of Formula 5 from the full wavefield record ]0(z0) of the seismic data of Formula 3 using a purely data-driven method without any prior conditions or reliance on any geological model.

[0083] The implementation theory of 0D-SRME is as follows:

[0084] Formula 1 to Formula 5 are continuous functions, which are the integration process of Fourier transform or Laplace transform at a time point; if converted into discrete functions, they become the convolution between channels.

[0085] Attached Figure 1 This is a schematic diagram of a zero-offset 0D-SRME. Figure 1 a is the ray path, Figure 1 b is a schematic diagram of seismic wave patterns. When a primary wave is convolved with itself, a secondary wave is generated. The ray path after convolution is a multiple path, and the propagation time is twice that of the primary wave, that is, the propagation time of the multiple wave. When the wave is reflected back from the water surface to generate multiple waves, the reflection coefficient of the water surface is -1, so we have Figure 1 When the convolution is performed, a “-” sign is added. The primary wave is reflected once by the seabed, and the secondary wave is reflected twice by the seabed. The amplitude intensity of the convolution of the primary wave and itself is exactly the intensity of the secondary wave. Therefore, the multiple waves after simple convolution are consistent with the actual secondary wave in terms of reflection time, phase and amplitude intensity.

[0086] In the original data, there is no pure primary reflection, the data also contains secondary reflections and higher-order multiple reflections.

[0087] Attached Figure 2 It is a zero-offset primary wave and a secondary wave. For the sake of step-by-step description, we assume that we have taken measures to remove multiple waves and obtained a pure primary wave. Let it be convolved with the original trace containing multiple waves, and a secondary wave and a cubic wave will be generated! Here, the convolution of the primary wave and the primary wave produces a secondary wave, and the convolution of the primary wave and the secondary wave produces a cubic wave. In the following introduction, we will find that such a simple formula is suitable for the convolution of any multiple waves. The convolution of the Nth wave and the Mth wave will produce the N+Mth wave.

[0088] In the actual original data, the above assumption that the means of removing multiple waves are taken to obtain a pure primary wave is just for the convenience of description. In fact, it does not exist. If it is really obtained, there is no need to suppress the multiple waves. The data also contains secondary reflections and higher-order multiple reflections.

[0089] Attached Figure 3 It is a zero-offset primary wave and a secondary wave. Let it convolve with itself, and the resulting wave is a secondary wave, a cubic wave, and a quartic wave. Here, the convolution of the primary wave and the primary wave produces a secondary wave, the convolution of the primary wave and the secondary wave produces a cubic wave, and the convolution of the secondary wave and the secondary wave produces a quartic wave. We will notice that the primary wave and the secondary wave are cross-convolved twice, so the amplitude of the generated cubic wave is twice that of the normal cubic wave. There are two ways to solve the amplitude anomaly. One is the adaptive subtraction method, which uses matched filtering to make the abnormal amplitude close to the true amplitude; the other is the iterative method, which goes through the multiple wave channel and then convolves it with the original channel to obtain multiple waves with abnormally small amplitudes.

[0090] If higher order waves are included, higher multiple waves will be predicted. Their general pattern is:

[0091] The convolution of the primary wave and the primary wave produces the secondary wave

[0092] The convolution of the primary and secondary waves produces the cubic wave

[0093] The convolution of the first and third waves produces the fourth wave

[0094] The convolution of a quadratic wave and a quadratic wave produces a quartic wave

[0095] The convolution of the quadratic and cubic waves produces the quintic wave

[0096] The convolution of the Mth wave and the Nth wave produces the M+Nth wave

[0097] …

[0098] The convolution of the Mth wave and the Nth wave produces the M+Nth wave

[0099] Application conditions of 0D-SRME

[0100] For general land data, the elimination of multiple waves related to the surface is not as easy and applicable as for marine data. Therefore, the application of surface-related multiple wave elimination technology in land seismic data is quite limited. In addition, the near-surface conditions during land acquisition are very different from the simple free surface conditions in the marine environment. It is much easier to find multiple waves in marine seismic data. They are generally seabed multiple waves, or in special cases, interlayer multiple waves generated by certain strong reflection layers under the seabed. On land, the multiple waves of land seismic data are difficult to identify, and the shape of the multiple waves varies, which depends on the surface undulation and the strong reflection interface that produces the multiple waves. In the time domain post-stack profile, the inclination of the multiple waves is steeper than that of the primary reflection wave, which causes the intersection with the adjacent phase axes above and below, and the morphological characteristics show abnormalities.

[0101] The present invention is different from traditional SRME, and is mainly applied to zero-offset data, and can also be applied to the result data after the offset. For zero-offset data, 0D-SRME multiple wave suppression of the target layer is performed in the time domain, so that those unfavorable factors that affect the application effect of 3D-SRME no longer exist. Here, we are targeting desert areas, where the surface undulation is not large, the static correction amount is relatively small, and can even be ignored, so there is no need to consider near-surface static correction and ray bending problems; for 0D-SRME of post-stack seismic data, the data must be placed on the floating surface, so that the first multiple wave can be twice the time of the initial reflection wave. In addition, because it is post-stack data, the shot and the inspection point are in the same position, there is no bending of the seismic wave ray, and there is no static correction problem in the data. The key is that the post-stack data fully meets the application conditions of 0D-SRME.

[0102] The near-surface conditions during land acquisition are very different from the simple free-surface conditions in the marine environment, so careful preprocessing of the input data is required. This is especially true when the signal-to-noise ratio of the seismic data is not high, which is a common problem and must be solved in land seismic acquisition. However, in many cases, the geological structure can be modeled as a one-dimensional layered medium, and the corresponding seismic data stack profile is considered to be a plane wave response. In this case, the multiple wave prediction process is simplified to the self-convolution of each stack trace, as shown in Figure 1 Zero offset 0D-SRME. Because it is post-stack data, such as CMP stack sections and offset sections, the signal-to-noise ratio of seismic data is relatively high, which provides relatively good conditions for the application of 0D-SRME. Self-convolution is performed on all stack sections to obtain predicted multiple waves, and then they are adaptively subtracted from the stack sections of the reference data to obtain the post-stack multiple wave removal result.

[0103] The adaptive subtraction of 0D-SRME is as follows:

[0104] The multiple waves predicted by 0D-SRME cannot be directly subtracted from the original data. Since the reflection coefficients of the formations with different amplitudes are averaged after the stacking process, the amplitude of the multiple waves predicted inconsistent with the expected amplitude will increase, and the phase will also deviate during the stacking process. Adaptive subtraction must be used to correct the amplitude and phase deviation of the predicted multiple waves. 0D-SRME is relatively accurate in predicting multiple waves, and its suppression effect also depends on the quality of parameter selection in the adaptive least squares matched filter subtraction process. On the profile record, the implementation process of the adaptive matched filter method and subtraction method based on the minimum energy criterion is to divide each channel into one or more time windows, perform single-channel or multi-channel matched filtering in each time window to calculate the matched filter operator that can achieve the best fit between the multiple wave model and the actual multiple wave record, and then apply the operator to the multiple wave model and subtract the corrected result from the original data. It can be seen that in the adaptive matched filtering stage, the filter length used to calculate the filter operator, the division of the processing time window, and the number of adjacent matching channels are crucial to the effect of 0D-SRME in attenuating multiple waves. The main control parameters of the adaptive matched filter operator need to be carefully tested and the optimal values ​​selected. The specific selection needs to be determined according to the actual situation. Since the primary and multiple waves can be easily distinguished in the forward model records, the main parameter characteristics of the method and the effect of suppressing free surface multiple waves can be tested using model data before applying 0D-SRME to process actual data.

[0105] The present invention is based on the driving principle of the post-stack data itself on land, and the predicted multiple waves have high accuracy. The 0D-SRME developed by the present invention is very efficient. The adaptive subtraction technology of the present invention can meet the needs of post-subtraction separation of multiple waves prediction. The present invention is not only suitable for offshore towing data, but also for any onshore acquisition system. The present invention can adopt iterative application to suppress the multiple waves between layers of ultra-deep target layers on land. For the first time, SRME is successfully applied to the suppression of multiple waves of onshore seismic data, and ideal results are achieved.

[0106] Embodiment 2:

[0107] Multiple suppression of model 1 data

[0108] In order to test the effectiveness of 0D-SRME in suppressing multiple waves of post-stack data, model data is first used. The wave equation finite difference method is a key and commonly used technology in seismic wave field simulation technology, and is widely used in model forward calculation, theoretical method and new method verification. The numerical simulation technology of seismic wave field is a technical method that uses theoretical calculation methods to study the propagation law of seismic waves in underground media when the structure and parameters of the underground media are known, so as to synthesize seismic records. Figure 4It is a 2D velocity model with the following parameters: horizontal length 17000 meters, vertical length 3500 meters, spatial grid wavelength dx = dz = 12.5 meters, sampling rate dt = 0.001 seconds, and recording length t = 6 seconds. The track spacing is 12.5 meters, with a total of 161 shots, and each shot has 321 detection points. The model consists of 5 layers of media, with velocities of v1 = 1500 m / s, v2 = 2200 m / s, v3 = 2700 m / s, v4 = 3000 m / s, and v5 = 4000 m / s. The second layer is an inclined reflection interface, and the thickness of each layer is as follows: Figure 4 As shown in Figure 1, multiple wave suppression test of CMP stacking data of velocity model 1; Figure 5 This is a schematic diagram of multiple wave suppression of CMP stacking data of velocity model 1. Figure 5 a is the superimposed section, Figure 5 b is the cross section after multiple wave suppression, Figure 5 c is the predicted multiple waves. It can be seen that 0D-SRME has achieved an ideal effect and the multiple waves have been suppressed. In particular, the multiple waves related to the inclined interface are also well suppressed, which proves the effectiveness of 0D-SRME in suppressing multiple waves of post-stack data. Figure 6 For the multiple suppression test of prestack time migration of model data, Figure 6 a in the middle is the pre-stack time migration section. Figure 6 Middle b is the section after multiple wave suppression of prestack time migration. Figure 6 Figure c is the predicted multiple wave. It can be seen that 0D-SRME also achieved an ideal effect in suppressing multiple waves in the prestack time migration profile, and the multiple waves were suppressed. In particular, the multiple waves related to the inclined interface were also well suppressed, which proves the effectiveness of 0D-SRME in suppressing multiple waves in prestack time migration data.

[0109] Model 2: Sigsbee model multiple suppression

[0110] The complex Sigsbee model is further applied to verify the effectiveness of 0D-SRME in suppressing multiple waves of post-stack data. Figure 7 It is a schematic diagram of multiple wave suppression in the superposition profile of the Sigsbee model. Figure 7 a is the Sigsbee speed model. Figure 7 b is the superposition section containing multiple waves. Figure 7 The middle c is the superposition section after multiple wave suppression. Figure 7 The middle d is the predicted multiple waves, and it can be seen that the seabed multiple waves are well suppressed. In addition, the prestack RTM depth migration profile needs to be converted from the depth domain to the time domain, and 0D-SRME is applied in the time domain. Figure 8 This is a schematic diagram of multiple wave suppression of Sigsbee model reverse time migration data. Figure 8 a in the middle is the time domain section containing multiple wave reverse time migration. Figure 8 Middle b is the reverse time migration time domain section after multiple wave suppression. Figure 8 In the figure c, it is the predicted multiple wave profile in the time domain. Fig. 9 This is the multiple wave suppression effect diagram of the Sigsbee model reverse time migration data. Fig. 9 The a in the middle is the depth domain profile containing multiple wave reverse time migration. Fig. 9 Middle b is the depth domain profile of reverse time migration after multiple wave suppression. Fig. 9 In c, multiple waves are converted to the depth domain. After comparison, the multiple wave suppression of the complex Sigsbee model also achieved ideal results, the cross-cutting axis phenomenon was eliminated, and the multiple waves were effectively suppressed.

[0111] The actual multiple wave suppression between ultra-deep target layers on the desert surface specifically includes the following steps:

[0112] In order to achieve the ideal multiple wave suppression effect, the actual profile data must be pre-processed, especially the elimination of shallow noise. First, the input data needs to be finely pre-processed. According to the technical requirements of 0D-SRME, the land desert seismic data is pre-processed conventionally to complete the profile after CMP gather stacking or migration. There is a certain signal-to-noise ratio, and the data is located on the floating datum surface, which meets the data required by 0D-SRME.

[0113] The data above the strong reflection layer in the actual profile data must be cut off. The cutting should be carried out along the reflection layer. The effect of cutting should be similar to the seabed reflection to obtain the profile data after cutting off. Which reflection interface is used to simulate the seabed will seriously affect the effect of 0D-SRME. The predicted multiple waves are related to the underlying strata closest to the cutting off, because the multiple waves are the images of the strata below the cutting off point.

[0114] The predicted multiple waves were obtained by combining 0D-SRME with the cross-sectional data after resection.

[0115] The predicted multiple waves are subtracted from the input data by using least squares adaptive subtraction, which ensures that the multiple waves of the seismic data are eliminated and the profile data with multiple waves eliminated are obtained.

[0116] Attached Fig.10 a in the middle is the prestack time migration section with multiple suppressed wavefronts. Fig.10 b is the prestack time migration section after multiple wave elimination. Fig.11 is the predicted multiple wave, that is Fig.10 A and Fig.10The 0D-SRME multiple wave suppression technology better predicts the multiple waves developed on the prestack time migration section. The prestack time migration section after suppression has a better signal-to-noise ratio and more accurate reflection homing, which improves the intersection problem of the Cambrian-Ordovician phase axis, making the contact relationship between the Ordovician buried hill and the internal strata clearer and more reliable than before suppression. At the same time, it also reduces the ambiguity of the identification of the Cambrian salt layer, especially the internal strata of the bedrock.

[0117] This paper proposes a 0D-SRME surface multiple wave elimination method based on the wave equation. The effectiveness and practicality of the proposed method are demonstrated by applying two sets of model data and actual land desert surface post-stack seismic data. In the process of model testing, the model CMP gather stacking profile and pre-stack time migration profile have the characteristics of high signal-to-noise ratio and balanced amplitude. The application of 0D-SRME has achieved good results; in all the models and actual desert seismic data examples, the data before and after multiple wave suppression are displayed with the same amplitude level, and the amplitude of the removed multiple waves needs to be adjusted to the same level, so that it is convenient to compare the results. These test results also verify the effectiveness of the method.

[0118] Based on the above method, the present invention also discloses an interlayer multiple wave suppression system, including: a data acquisition module, a data removal module, a multiple wave prediction module and a multiple wave elimination module;

[0119] Data acquisition module: used to obtain actual profile data;

[0120] Data removal module: used to remove the data above the strong reflection layer in the actual profile data to obtain the profile data after removal;

[0121] Multiple wave prediction module: used to predict the predicted multiple waves by using 0D-SRME combined with the section data after resection;

[0122] Multiple wave elimination module: It is used to adaptively subtract the predicted multiple waves from the actual profile data using the least squares method to obtain the profile data with the multiple waves eliminated.

[0123] See also Fig.13In another feasible embodiment of the present invention, the following is adaptively modified according to the situation. Data acquisition module, data excision module, multiple wave prediction module and multiple wave elimination module. The data acquisition module is used to obtain actual profile data. The data excision module is used to excise the data above the strong reflection layer in the actual profile data to obtain the profile data after excision, so as to achieve an effect similar to the seabed reflection, so that the profile data after excision meets the requirements of 0D-SRME. The multiple wave prediction module is used to use 0D-SRME to combine the profile data after excision to predict the predicted multiple waves. The multiple wave elimination module is used to use the least squares method to adaptively subtract the predicted multiple waves from the actual profile data to obtain the profile data with the multiple waves eliminated. The least squares method is used for adaptive subtraction to correct the amplitude and phase deviation of the predicted multiple waves, so as to ensure the elimination of multiple waves of seismic data. By applying 0D-SRME to effectively suppress and eliminate multiple waves and interlayer multiple waves, the effective signal of seismic data is restored, the false is eliminated and the true is retained, and the imaging quality of ultra-deep seismic profiles on land is scientifically and rationally improved. The modules cooperate with each other to effectively suppress the multiple waves between layers. The multiple wave prediction accuracy is high, the suppression effect is good, and the reliability of seismic imaging is improved.

[0124] An electronic device comprises: a processor; a memory for storing computer program instructions; and steps for implementing a method for automatically synchronizing historical data with a real-time database when executing the computer program.

[0125] A storage medium stores computer program instructions. When the computer program instructions are loaded and run by a processor, the processor executes a method for automatically synchronizing historical data with a real-time database.

[0126] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0127] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0128] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0129] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0130] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A method for suppressing interlayer multiple waves, characterized in that: The steps include: Obtain actual profile data; Cut off the data above the strong reflection layer in the actual profile data to obtain the profile data after cutting off; The predicted multiple waves were obtained by using 0D-SRME combined with the section data after resection; The predicted multiple waves are adaptively subtracted from the actual profile data using the least squares method to obtain profile data with multiple waves eliminated.

2. The method for suppressing multiple waves between layers according to claim 1, characterized in that: The actual profile data needs to be preprocessed, and the actual profile data is preprocessed to the profile after the CMP gather is stacked or the migration is completed.

3. The method for suppressing interlayer multiple waves according to claim 1, characterized in that: When the data above the strong reflection layer in the actual profile data is cut, the cutting should be performed along the reflection layer.

4. The method for suppressing interlayer multiple waves according to claim 1, characterized in that: The multiple waves predicted by using 0D-SRME combined with the cross-section data after resection are as follows: Each section data after resection is divided into at least one time window, at least one matched filter is performed in each time window to obtain a matched filter operator, and then 0D-SRME combined with the filter operator is used for prediction to obtain the predicted multiple waves.

5. The method for suppressing interlayer multiple waves according to claim 4, characterized in that: The 0D-SRME is specifically as follows: P(z0)=D - (z0)X0(z0,z0)[S + (z0)+R - (z0)P - (z0)]=P0(z0)+M0(z0) P0(z0)=D-(z0)X0(z0,z0)S + (z0) M0(z0)=D-(z0)X0(z0,z0)[R-(z0)P-(z0)] Among them, P(z0) is the primary reflection wave, M0(z0) is the multiple reflection wave; X0(z0, z0) is the underground propagation operator without interlayer multiple waves, R- is the reflection operator of the upgoing wave, S + (z0) is the source wavefield at the sea surface z0, D-(z0) is the receiver operator, and P-(z0) is the upgoing wavefield.

6. The method for suppressing interlayer multiple waves according to claim 5, characterized in that: The X0(z0, z0) is specifically as follows: Among them, R + is the reflection operator of the downgoing wave, W- is the propagation operator of the upgoing wave, and W + is the propagation operator of the downlink wave.

7. The method for suppressing interlayer multiple waves according to claim 5, characterized in that: The P-(z0) is specifically as follows: If the interlayer multiple waves are ignored, P-(z0) is: If all multiple waves are ignored, P-(z0) is: Among them, P + (z0) is the downlink wave field.

8. An interlayer multiple wave suppression system as claimed in claim 1, characterized in that: include: Data acquisition module, data removal module, multiple wave prediction module and multiple wave elimination module; Data acquisition module: used to obtain actual profile data; Data removal module: used to remove the data above the strong reflection layer in the actual profile data to obtain the profile data after removal; Multiple wave prediction module: used to predict the predicted multiple waves by using 0D-SRME combined with the section data after resection; Multiple wave elimination module: It is used to adaptively subtract the predicted multiple waves from the actual profile data using the least squares method to obtain the profile data with the multiple waves eliminated.

9. An electronic device, comprising: A processor; a memory for storing computer program instructions; characterized in that it is used to implement the steps of the method for automatically synchronizing historical data with a real-time database as described in any one of claims 1-7 when executing the computer program.

10. A storage medium storing computer program instructions, characterized in that: When the computer program instructions are loaded and executed by the processor, the processor executes the method for automatically synchronizing historical data with a real-time database according to any one of claims 1 to 7.

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