阅读说明：本技术 利用速度特征压制沙丘鸣震的方法 (Method for suppressing sand dune ringing by using speed characteristics ) 是由 宋智强 徐雷良 刘斌 赵国勇 徐钰 杨德宽 朱迪 姜海波 李伟 曹宇宁 高健 于 2020-05-26 设计创作，主要内容包括：本发明提供一种利用速度特征压制沙丘鸣震的方法,包括：步骤1,对单炮数据进行静校正；步骤2,进行正演模拟确定沙丘鸣震类型,当确定沙丘鸣震类型是接收点鸣震,流程进入到步骤3；当确定沙丘鸣震类型是激发点、接收点鸣震共存的现象,流程进入到步骤6；步骤3,将资料抽取共检波点道集；步骤4,进行炮检距排序,压制接收点鸣震；步骤5,抽回共炮点道集,对比压制效果；步骤6,压制接收点鸣震；步骤7,抽共检波点道集,进行炮检距排序；步骤8,抽回共炮点道集,对比压制效果。该利用速度特征压制沙丘鸣震的方法能够有效针对沙丘鸣震噪音进行去除,提高资料的信噪比。(The invention provides a method for suppressing dune ringing by using speed characteristics, which comprises the following steps: step 1, performing static correction on single shot data; step 2, performing forward modeling to determine the type of the sand dune acoustic shock, and entering the step 3 when the sand dune acoustic shock type is determined to be the reception point acoustic shock; when the sand dune ring vibration type is determined to be the phenomenon that the excitation point and the receiving point are in the resonance coexistence, the flow enters the step 6; step 3, extracting a common detection point gather from the data; step 4, performing offset sorting and suppressing receiving point ringing; step 5, drawing back the common shot gather, and comparing the pressing effect; step 6, suppressing the receiving point to sound; step 7, extracting a common detection point gather, and sequencing shot-geophone distances; and 8, drawing back the common shot gather, and comparing the pressing effect. The method for suppressing the sand dune ringing by using the speed characteristics can effectively remove the sand dune ringing noise and improve the signal-to-noise ratio of data.)

1. The method for suppressing the sand dune acoustic shock by utilizing the speed characteristics is characterized by comprising the following steps of:

step 1, performing static correction on single shot data;

step 2, performing forward modeling to determine the type of the sand dune acoustic shock, and when the type of the sand dune acoustic shock is determined to be a receiving point acoustic shock, the process enters step 3, and when the type of the sand dune acoustic shock is determined to be an excitation point and a receiving point acoustic shock coexists, the process enters step 6;

step 3, extracting a common detection point gather from the data;

step 4, performing offset sorting and suppressing receiving point ringing;

step 5, drawing back the common shot gather, and comparing the pressing effect;

step 6, suppressing the receiving point to sound;

step 7, extracting a common detection point gather, and sequencing shot-geophone distances;

and 8, drawing back the common shot gather, and comparing the pressing effect.

2. The method of suppressing sand dune blasts using the velocity signature as recited in claim 1 wherein, in step 1, single shot data is staticized to eliminate surface elevation differences and near surface induced moveout problems.

3. The method for suppressing sand dune seismic singing according to claim 1, wherein in step 2, the near surface model of the work area is established by collecting the work area surface elevation data, including the actually measured surface elevation data of the shot point geophone point, and collecting the micro-logging data of the work area for surface layer data interpretation, the wave field information is analyzed through forward simulation, and the actual single shot data characteristics are combined to analyze the main components of the sand dune seismic singing of the area, and whether the receiving point seismic is the main component or the excitation point and the receiving point seismic coexist is determined.

4. The method of suppressing sand dune seismic events according to claim 1, wherein in step 3, when it is determined by wavefield simulation analysis that the sand dune seismic events are mainly received point seismic events, the data is extracted into a common detector point gather.

5. The method for suppressing sand dune seismic according to claim 1, wherein in step 4, sorting is performed according to the magnitude of offsets in the gather of common detector points, and after the offsets are sorted according to the magnitude, the sand dune seismic and the reflected wave have obvious velocity difference, which is beneficial to separation, and the sand dune seismic is removed by adopting a velocity characteristic filtering method, and the reflected wave information is left.

6. The method for suppressing sand dune seismic singing according to claim 1, wherein in step 5, the data after sand dune seismic singing is removed is extracted back to the common shot gather to complete suppression of sand dune seismic singing, and the single shot data after sand dune seismic suppression and the single shot data before suppression are compared in effect to determine the suppression effect.

7. The method for suppressing sand dune singing according to claim 1, wherein in step 6, when the sand dune singing type determined by the wave field simulation analysis is the phenomenon of coexistence of excitation point and receiving point singing, the linear noise removing method is firstly adopted in the shot domain to remove the excitation point sand dune singing.

8. The method for suppressing sand dune seismic acquisition using velocity signature as claimed in claim 1 wherein, in step 7, single shot data from which firing point seismic acquisition was removed is decimated into common geophone point gathers and sorted by shot-to-geophone distance size within the common geophone point gathers; at this time, the remaining receiving line ringing and the reflected wave have obvious speed difference, which is beneficial to separation, and a speed characteristic filtering method is adopted to remove the sand dune ringing at the receiving point and leave the reflection information.

9. The method for suppressing sand dune seismic acquisition according to claim 1, wherein in step 8, the data after removing the sand dune seismic acquisition is extracted to the shot gather to complete the suppression of the sand dune seismic acquisition; and comparing the effect of the single shot data after the suppression of the seismic shock of the sand dune with the effect of the single shot data before the suppression to determine the suppression effect.

Technical Field

The invention relates to the technical field of desert area main noise suppression, in particular to a method for suppressing sand dune ringing by using speed characteristics.

Background

A large number of oil and gas fields are distributed in the western region of China in a large desert, the oil and gas reserves are large, but the exploitation difficulty is high, and the major reasons for the difficulty are that the earth surface is a huge desert, the sand layer is loose, the absorption and attenuation of seismic waves are serious, the surface fluctuation is large, and a large number of secondary interference waves are generated, so that the signal-to-noise ratio of seismic data is low, and the oil and gas exploitation in the desert region is difficult to meet. The earth surface is loose, so that seismic waves reflected from the underground are greatly attenuated, the energy is low, sand dunes on the earth surface fluctuate violently, the seismic waves propagated near the earth surface encounter tall sand dunes to generate a complex near-earth surface interference wave field, the underground weak reflection information is seriously covered, the signal-to-noise ratio of seismic data in desert areas is low as a whole, and shadows of effective waves are difficult to see in some areas. In the past, the noise in desert areas is mainly recognized by surface waves and refracted waves which are easy to recognize, and sand dune singing which really influences the signal-to-noise ratio of data is realized.

In the application No.: 201811292104.9, relates to a wave equation continuation-based near-surface noise suppression method, which comprises: step 1, inputting a near-surface velocity thickness model; step 2, sorting the data into common cannons and common check gather; step 3, extending the demodulator probe by the common shot gather to a low-speed bottoming interface; step 4, extending the demodulator probe by the common shot gather to the earth surface upwards; and 5, reselecting the data after the continuation of the shot points and the demodulator probes, and extracting and retrieving the common shot gather again to finish output. The method is characterized in that a near-surface model is established, and then interference waves are simulated through finite difference forward modeling. This method is theoretically possible, but the biggest and most critical problem of this method is the accuracy of the established near-surface model. If the established near-surface model is completely the same as the model of the actual surface, the real interference waves can be truly simulated, but the micro-logging grid points for performing near-surface detection by actual field seismic acquisition are grids of 2kmx2km, namely, survey point data of near-surface data is provided every 2 kilometers on the surface, the near-surface data collected by the sparse grid points is asked for asking, the established near-surface model is very accurate, and the camera with low resolution cannot shoot the head of a long-distance person, so that the imprecise establishment of the near-surface model cannot simulate the accurate near-surface interference waves, the accurate downward extension of the wave field of the wave detection point cannot be truly realized, and the accurate upward extension of the wave field of the shot point cannot be realized.

In the application No.: 200710121262.3, relating to a method for suppressing true three-dimensional seismic data linear noise, the method comprises the following steps: collecting and recording high-density seismic data; dividing the data into minimum data set data groups; sequencing all the tracks of each data group according to the offset and the azimuth angle to form a three-dimensional de-noising minimum data set; analyzing the velocity of linear noise according to the formed frequency wave number spectrum (FK spectrum) or original seismic data, and removing the linear noise; and repeatedly pressing the existence of linear noise until the noise is removed. The method extracts the seismic data into a minimum data set for processing so as to obtain the characteristics of obvious regular interference waves, and therefore the irregularly acquired data can be denoised in a three-dimensional linear way. The biggest defect of the invention is that the problem of the space sampling theorem cannot be avoided, data is extracted into the minimum data set by taking the receiving line distance and the gun line distance as units, although the data comparison is regular, the problem of serious space spurious frequency can be generated for various wave fields due to the fact that the receiving line distance and the gun line distance are too large, the space sampling theorem cannot be satisfied, and for any interference wave, if too many space spurious frequencies are generated, the interference wave cannot be effectively removed.

Therefore, a novel method for suppressing the sand dune ringing by using the speed characteristics is invented, and the technical problems are solved.

Disclosure of Invention

The invention aims to provide a method for suppressing sand dune ringing by utilizing sand dune ringing characteristics expressed in data in different desert areas and utilizing speed characteristics separated from the data according to the different types of sand dune ringing characteristics.

The object of the invention can be achieved by the following technical measures: the method for suppressing the sand dune ringing by utilizing the speed characteristics comprises the following steps: step 1, performing static correction on single shot data; step 2, performing forward modeling to determine the type of the sand dune acoustic shock, and when the type of the sand dune acoustic shock is determined to be a receiving point acoustic shock, the process enters step 3, and when the type of the sand dune acoustic shock is determined to be an excitation point and a receiving point acoustic shock coexists, the process enters step 6; step 3, extracting a common detection point gather from the data; step 4, performing offset sorting and suppressing receiving point ringing; step 5, drawing back the common shot gather, and comparing the pressing effect; step 6, suppressing the receiving point to sound; step 7, extracting a common detection point gather, and sequencing shot-geophone distances; and 8, drawing back the common shot gather, and comparing the pressing effect.

The object of the invention can also be achieved by the following technical measures:

in step 1, static correction is carried out on the single shot data, and the problems of surface height difference and time difference caused by the near surface are solved.

In step 2, surface elevation data of the work area, including actually measured surface elevation data of shot point geophone points, and micro-logging data of the work area are collected to perform surface data interpretation, a near-surface model of the work area is established, wave field information is analyzed through forward simulation, and main components of the district dune singing are analyzed by combining actual single-shot data characteristics, and whether receiving point singing is the main component or excitation point singing coexisting is determined.

In step 3, when the sand dune acoustic shock is determined to be mainly receiving point acoustic shock through wave field simulation analysis, a common detection wave point gather is extracted from the data.

And 4, sequencing according to the magnitude of the shot-geophone distance in the common detector gather, wherein after the shot-geophone distance is sequenced according to the magnitude, the sand dune ringing and the reflected wave have obvious speed difference, so that the separation is facilitated, and the sand dune ringing is removed by adopting a speed characteristic filtering method, so that the reflection information is left.

And 5, extracting the data without the sand dune singing shock back to the shot-sharing gather to complete the suppression of the sand dune singing shock, and comparing the effect of the single shot data after the sand dune singing shock is suppressed with the effect of the single shot data before the suppression to determine the suppression effect.

In step 6, when the determined type of the sand dune singing is the phenomenon that the excitation point and the receiving point singing coexist through the wave field simulation analysis, firstly, the linear noise removing method is adopted in the shot domain to remove the sand dune singing of the excitation point.

In step 7, extracting the single shot data without the excitation point to form a common-geophone point gather, and sorting the single shot data in the common-geophone point gather according to the size of shot-geophone offset; at this time, the remaining receiving line ringing and the reflected wave have obvious speed difference, which is beneficial to separation, and a speed characteristic filtering method is adopted to remove the sand dune ringing at the receiving point and leave the reflection information.

In step 8, the data without the sand dune ringing is extracted back to the common shot gather to complete the suppression of the sand dune ringing; and comparing the effect of the single shot data after the suppression of the seismic shock of the sand dune with the effect of the single shot data before the suppression to determine the suppression effect.

The method for suppressing the sand dune seismic singing by using the speed characteristics can effectively remove the sand dune seismic singing noise and improve the signal-to-noise ratio of data, firstly determines the main wave field types of the sand dune seismic singing, establishes a near-surface model by using near-surface and near-surface elevation data of a work area, analyzes the sand dune seismic singing wave field characteristics through forward simulation, determines the main wave field types of the sand dune seismic singing of the work area according to the expression characteristics of the actual single-shot sand dune seismic singing wave field, has two practical conditions, mainly receives point sand dune singing, such as southern Xinjiang desert, and has the coexistence of point seismic excitation and point seismic reception, such as northern desert, and then sets different suppression processes according to different sand dune seismic wave field types. In the first case, data are subjected to static correction, the data are extracted to a common detection wave point gather, the common detection wave point gather is sorted according to the magnitude of offset, the sand dune ringing is removed by utilizing the difference of effective waves and the sand dune ringing at the receiving point in terms of speed and the speed characteristic of the sand dune ringing at the receiving point, then the data are extracted back to the common shot point gather, and the effect after pressing is compared with the effect before pressing. And in the second case, performing static correction on the data, eliminating the excitation point ringing by utilizing the speed characteristic of the excitation point ringing according to the difference of the excitation point ringing and the effective wave in speed in the shot-sharing point gather, then extracting the data to the shot-sharing point gather, sequencing the shot-sharing point gather according to the magnitude of shot-geophone distance, eliminating the sand dune ringing by utilizing the difference of the effective wave and the sand dune ringing in speed of the received point sand dune ringing, then extracting the data back to the shot-sharing point gather, and comparing the pressed effect with the effect before pressing. The method can effectively suppress the sand dune ringing noise and effectively improve the signal-to-noise ratio of the seismic data.

Drawings

FIG. 1 is a flow chart of one embodiment of a method of suppressing a dune ring using velocity signature in accordance with the present invention;

fig. 2 is a diagram illustrating an effect of applying the present invention in an embodiment of the present invention.

Detailed Description

In order to make the aforementioned and other objects, features and advantages of the present invention comprehensible, preferred embodiments accompanied with figures are described in detail below.

As shown in fig. 1, fig. 1 is a flow chart of the method for suppressing a sand hill blast using a velocity profile according to the present invention.

In step 101, single shot data is statically corrected to eliminate the problem of surface height difference and time difference caused by the near surface, so that the characteristics of the sand dune seismic wave field are clearer and more continuous, and removal is facilitated. The flow proceeds to step 102.

In step 102, a near-surface model of the work area is established by collecting work area surface elevation data, including actually measured surface elevation data of shot point geophone points, and collecting work area micro-logging data for surface layer data interpretation, wherein the model is used for analyzing a sand dune acoustic generation mechanism and a main sand dune acoustic type, and is different from the requirement of the patent application No. 201811292104.9 on the model, and the required model precision is not required to be very high but is only used for analyzing main components of the sand dune acoustic. Through forward simulation analysis of wave field information and combination of actual single shot data characteristics, the main components of the district dune singing earthquake are analyzed, and whether receiving point singing earthquake is the main component or excitation point and receiving point singing earthquake coexist is determined. When it is determined that the dune ring earthquake type is mainly reception of point earthquake, the flow proceeds to step 103; when it is determined that the dune ring earthquake type is the phenomenon that the excitation point and the reception point earthquake coexist, the flow proceeds to step 106;

In step 103, if it is determined that the dune seismic event is primarily a reception point seismic event, the data is extracted into a common detector point gather. The flow proceeds to step 104.

In step 104, sorting is performed in the common detection wave point gather according to the magnitude of the shot-geophone distance, and after the shot-geophone distance is sorted according to the magnitude, the sand dune ringing and the reflected wave have obvious speed difference, which is beneficial to separation, so that the sand dune ringing is removed by adopting a speed characteristic filtering method, and the reflection information is left. The flow proceeds to step 105.

In step 105, the data after the sand dune ringing is removed is extracted back to the shot-sharing gather, the suppression of the sand dune ringing is completed, the single shot data after the sand dune ringing is suppressed is compared with the single shot data before the suppression, and the suppression effect is determined.

In step 106, if the determined type of the dune ring is the phenomenon that the excitation point and the receiving point ring are coexisted through the wave field simulation analysis, the dune ring at the excitation point is firstly removed in the shot domain by a method of removing linear noise. The flow proceeds to step 107.

In step 107, the single shot data without the firing point is extracted into a common geophone point gather, and sorted according to the magnitude of the shot-geophone distance in the common geophone point gather. At this time, the remaining receiving line ringing and the reflected wave have obvious speed difference, which is beneficial to separation, so that a speed characteristic filtering method is adopted to remove the sand dune ringing at the receiving point and leave the reflection information. The flow proceeds to step 108.

In step 108, the data without the dune seismic is extracted back to the common shot gather, and the suppression of the dune seismic is completed. And comparing the effect of the single shot data after the suppression of the seismic shock of the sand dune with the effect of the single shot data before the suppression to determine the suppression effect.

As shown in fig. 2. FIG. 2 is a single shot effect diagram before and after the method is applied, and it can be seen that the signal-to-noise ratio of the single shot before the application is low, the reflection in-phase axis is unclear, a large amount of sand dune ringing interference exists, the signal-to-noise ratio of the single shot after the application is obviously improved, the reflection in-phase axis is very clear and continuous, the sand dune ringing phenomenon is weakened, and the method is very favorable for completing geological target imaging.

The method for suppressing the sand dune acoustic shock by utilizing the speed characteristics simulates the wave field characteristics of the sand dune acoustic shock by establishing a near-surface model forward simulation, analyzes the main components of a sand dune acoustic wave field by combining with the wave field characteristics of actual data, determines whether the receiving of the point acoustic shock is dominant or the point acoustic shock is excited and the point acoustic shock is received and coexists, and works out a corresponding processing flow and a method according to the two conditions. For the data mainly for receiving the point sand dune singing earthquake, firstly, the data needs to be subjected to static correction processing, then the data is extracted to a common detection point gather, the common detection point gather is sorted according to the magnitude of the offset, and the point sand dune singing earthquake is separated according to the speed difference between the effective wave and the point sand dune singing earthquake in the data performance characteristics. And then, extracting the processed data back to the common shot gather. For the condition that the excitation point sand dune ringing and the receiving point sand dune ringing coexist, the data needs to be subjected to static correction processing firstly, then the excitation point sand dune ringing is separated from the effective wave on the basis of the speed difference of the excitation point sand dune ringing and the effective wave on the shot point gather, and then the data is extracted to the common detection wave point gather. And sorting the common detection wave point gathers according to the magnitude of the offset, and separating the sand dune singing shakes of the receiving points according to the speed difference between the effective waves and the sand dune singing shakes of the receiving points in the data expression characteristics. And then, extracting the processed data back to the common shot gather.

The method for suppressing the sand dune acoustic shock by using the speed characteristics researches the corresponding suppressing method aiming at the sand dune acoustic shock wave field characteristics of different areas, can effectively eliminate the influence of the sand dune acoustic shock, and effectively improves the signal-to-noise ratio of the desert data.