Method for selecting matching relationship between excitation parameters of well gun and vibroseis

Abstract

The invention provides a method for selecting a matching relationship between excitation parameters of a well gun and a vibroseis, and the method comprises the steps: 1, carrying out the partitioning of the ground surface of a work area, and carrying out the single-gun test of the well gun and the vibroseis; step 2, performing static correction and denoising processing on the single shot; 3, copying the processed single shot, and modifying coordinate information; 4, superposing different coverage times of single shots of the well shot and the vibroseis respectively, and analyzing signal-to-noise ratios of the single shots with different coverage times respectively; and 5, finding out the coverage times of the well shot and the vibroseis with the same signal-to-noise ratio, and solving a matching relation on other earth surfaces by using the same method. The method for selecting the matching relationship between the excitation parameters of the well shot and the vibroseis can effectively improve the selection correctness of acquisition factors for a deep target, and lays a foundation for reasonably selecting the acquisition factors.

Description

Technical Field

[0001] The present invention relates to the technical field of oilfield development, and in particular to a method for selecting a matching relationship between well guns and controllable vibrator excitation parameters. Background Art

[0002] The Junggar Basin boasts rich oil and gas resources, but its surface conditions are complex and diverse, encompassing farmland, desert fringes, and the heart of the desert. Within these diverse near-surface conditions, water content and the depth of the water table determine data quality, significantly impacting both well and vibroseis acquisition. However, current practices employ consistent parameters for both well and vibroseis acquisition, even across varying surface conditions. For example, a vibroseis acquisition of 1,000 coverages in farmland would be equivalent to the same number in desert areas. This lack of targeted operation hinders data quality. Therefore, optimizing the appropriate parameters for each surface condition is crucial to addressing the challenges of imaging data in diverse near-surface conditions.

[0003] The Chinese patent application with application number CN202010013593.0 relates to a method and apparatus for matching seismic data collected by a mixture of well-shot and vibroseis. The method comprises: adjusting the vibroseis records and well-shot records in the seismic data to the same energy level; extracting the well-shot records and vibroseis records from the seismic data, and performing minimum phase conversion on the vibroseis records to obtain phase-converted vibroseis records; denoising the phase-converted vibroseis records and well-shot records; performing longitudinal energy compensation on the denoised vibroseis records and the denoised well-shot records; adjusting the phase of the longitudinally energy-compensated vibroseis records to a mixed phase; superimposing the mixed-phase vibroseis records with the longitudinally energy-compensated well-shot records to obtain superimposed data; and eliminating the time difference between the vibroseis records and the well-shot records in the superimposed data. This solution solves the problem of more adaptable matching of well-shot and seismic data with low signal-to-noise ratio. It does not solve the problem of how to choose the matching relationship between the controllable source and the coverage number of well guns according to the near-surface conditions in different areas to better suppress the secondary interference on the surface.

[0004] The Chinese patent application, application number CN202011193649.1, relates to a method and apparatus for matching the number of vibroseis excitation combinations with the number of coverages. The method comprises: determining multiple sets of test data based on historical vibroseis excitation test line data from a target work area, each set of test data containing a corresponding relationship between the number of vibroseis excitation combinations and the number of coverages of the observation system; obtaining the seismic profiles corresponding to each set of test data, and determining the signal-to-noise ratio data of each seismic profile within a set time window of the target exploration layer; and obtaining the matching target number of vibroseis excitation combinations and the target number of coverages of the observation system based on a matching formula. This application can closely link the number of vibroseis excitation combinations, which primarily affects the quality of seismic data, with the number of coverages in the observation system, and can effectively improve the quality of seismic acquisition data while reducing the cost of seismic acquisition work. The invention aims to obtain a method for matching the number of vibroseis excitation combinations with the number of coverages, referring to the relationship between the two parameters when the vibroseis is excited by itself, without considering the matching relationship between the vibroseis and the well gun, or the relationship between the two excitation modes.

[0005] In the Chinese patent application with application number: CN202111275689.5, a seismic data matching method, device, storage medium and electronic equipment are involved, including: determining the same number of multiple vibroseis seismic traces and multiple explosive source seismic traces according to the construction design of the target area; performing phase rotation on each vibroseis seismic trace according to a preset angle interval, and performing structural similarity evaluation on the signal of each explosive source seismic trace and the signal of the corresponding vibroseis seismic trace to obtain the optimal phase rotation angle of each vibroseis seismic trace; calculating the average to obtain the optimal average phase rotation angle of the target area; performing phase rotation on all vibroseis seismi in the target area to obtain matched vibroseis data. This application obtains a more accurate phase rotation angle through quantitative phase rotation and similarity evaluation, which can better achieve the same-phase superposition of vibroseis seismi and explosive sources, effectively improving the quality of seismic imaging. This invention is based on the consideration of the phase rotation of vibroseis and well guns, and selects the optimal phase for superposition through different phase rotations. It does not solve the problem of how to choose the matching relationship between the controllable source and the coverage number of well guns according to the near-surface conditions in different areas to better suppress the secondary interference on the surface.

[0006] The Chinese patent application with application number CN201611235414.8 discloses a method for matching inhomogeneous near-surface seismic detection combined intra-group distances, including the following steps: Step 1: improving the combined noise suppression formula based on the traditional seismic exploration principle to derive a new intuitive formula for calculating the combined noise suppression response with the wavelength of the interference wave as the main variable; Step 2: fitting the seismic detection combined noise suppression response curves at different intra-group distances using the new formula; Step 3: fitting and extracting the quantitative matching formula for the seismic detection group distances; Step 4: simulating and verifying the seismic detection combined noise suppression responses at different intra-group distances; and Step 5: analyzing the overall noise suppression effect based on actual data. This method for matching inhomogeneous near-surface seismic detection combined intra-group distances solves the problems of complex interference and low signal-to-noise ratio in seismic data in similar areas. It has great application value and can even be applied to all complex surface and near-surface areas in a targeted manner. It has a wide range of applications and good application prospects. This invention is aimed at the problem of selecting the internal distance of the detector combination. How to select the internal distance of the detector combination can better suppress noise. It is aimed at the situation at the receiving end and does not consider how to select the matching coverage times of the controllable seismic source at the excitation end and the well gun to suppress noise.

[0007] The above existing technologies are all significantly different from the present invention and fail to solve the technical problem we want to solve. Therefore, we have invented a new method for selecting the matching relationship between well gun and controllable vibrator excitation parameters. Summary of the Invention

[0008] The purpose of the present invention is to provide a method for selecting the matching relationship between well gun and controllable vibroseis excitation parameters, which can effectively improve the accuracy of selecting acquisition factors for quasi-medium and deep targets.

[0009] The object of the present invention can be achieved by the following technical measures: a method for selecting a matching relationship between well gun and controllable vibrator excitation parameters, the method for selecting a matching relationship between well gun and controllable vibrator excitation parameters comprising:

[0010] Step 1: Divide the surface of the work area into sections and conduct well shot and vibroseis single shot tests respectively;

[0011] Step 2: Perform static correction and denoising on the single shot;

[0012] Step 3: Copy the processed single shot and modify the coordinate information;

[0013] Step 4: Superimpose different coverage times of well shot and vibroseis single shot respectively, and analyze the signal-to-noise ratio of the single shot with different coverage times;

[0014] Step 5: Find the well gun and vibroseis coverage times with the same signal-to-noise ratio, and use the same method to obtain matching relationships on other surfaces.

[0015] The purpose of the present invention can also be achieved by the following technical measures:

[0016] In step 1, the surface conditions of the work area are divided into types, and a representative place is selected as a test point for each type of surface.

[0017] In step 1, well gun and vibroseis single shot acquisition tests are carried out at each test point, with the well gun and vibroseis firing one shot each, and the shot point is located in the middle of the arrangement.

[0018] In step 2, after the single-shot acquisition is completed, the data needs to be statically corrected to eliminate the time difference problem caused by the surface height difference.

[0019] In step 2, after static correction, linear noise removal is performed. Because the high-speed layer interface will produce more linear secondary interference, which seriously affects the signal-to-noise ratio of a single shot, a certain velocity information is used for linear removal to eliminate the impact of noise on the effective reflection wave.

[0020] In step 2, the 1800 m / s velocity information is used for linear removal to eliminate the influence of noise on the effective reflected wave.

[0021] In step 2, after linear noise removal, dynamic correction is performed. In relatively flat areas of the formation, the formation is flattened after dynamic correction, which basically conforms to the formation characteristics.

[0022] In step 3, the single shot after dynamic correction is copied and the shot point coordinates of each shot are modified. When the coordinates of the shot point are changed, the coordinates of the corresponding detection points are also changed.

[0023] In step 4, the modified shot records are superimposed according to the coordinates to form a superimposed section, and the superposition is performed according to different coverage times.

[0024] In step 5, after superimposing the well gun and the vibrator single shot with different coverage times, the signal-to-noise ratios of the well gun and the vibrator with different coverage times are analyzed, so as to find the corresponding relationship between the coverage times of the well gun and the vibrator with the same signal-to-noise ratio under the surface conditions, that is, the matching relationship.

[0025] The purpose of the present invention can also be achieved through the following technical measures: a selection system for the matching relationship between well guns and controllable seismic source excitation parameters under different near-surface conditions. The selection system for the matching relationship between well guns and controllable seismic source excitation parameters under different near-surface conditions adopts a selection method for the matching relationship between well guns and controllable seismic source excitation parameters to consider the matching relationship between well guns and controllable seismic sources under different near-surface conditions to select acquisition factors for deep targets.

[0026] The method for selecting the matching relationship between well gun and controllable source excitation parameters in the present invention conducts research on the method for selecting well gun and controllable source construction parameters under different near-surface conditions in the quasi-middle layer. By conducting single-shot tests at different near-surface conditions, the influence of near-surface conditions on excitation is fully considered, and suitable acquisition parameters are analyzed, which is of great significance for improving the level of oil and gas exploration in the quasi-middle and deep layers. The present invention can effectively analyze the matching relationship for different near-surface conditions in the quasi-middle layer, while fully considering the influence of different near-surface conditions on the excitation wave field of well gun and controllable source. This method can effectively consider the matching relationship between well gun and controllable source under different near-surface conditions, effectively improve the correctness of the selection of acquisition factors for deep targets, and lay the foundation for the reasonable selection of acquisition factors. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A flowchart of a specific embodiment of the method for selecting the matching relationship between well gun and vibroseis excitation parameters of the present invention;

[0028] Figure 2 This is a rendering of the effect obtained by using this method in a specific embodiment of the present invention. DETAILED DESCRIPTION

[0029] It should be noted that the following detailed descriptions are exemplary and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present invention belongs.

[0030] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations and / or combinations thereof.

[0031] like Figure 1 As shown, Figure 1 The flowchart of the method for selecting the matching relationship between the well gun and the controllable source excitation parameters of the present invention is as follows:

[0032] Step 101: The work area's surface is divided into zones, and well shot and vibroseis single shot tests are conducted. The zones are categorized based on the surface conditions of the central work area. For example, some work areas span a large area, encompassing three different surface areas: farmland, desert edge, and desert heartland. A representative location is selected for each surface type as a test point. Well shot and vibroseis single shot acquisition tests are then conducted at each test point. One well shot and one vibroseis shot are fired, with a range length of 14,000 meters and a trace spacing of 25 meters, with the shot point located in the center of the range.

[0033] Step 102: Perform static correction and denoising on the single shot. After the single shot acquisition is complete, the data needs to be statically corrected to eliminate the time difference caused by surface elevation differences. Linear noise removal is then performed. Because high-speed layer interfaces generate a significant amount of linear secondary interference, which can severely impact the signal-to-noise ratio of a single shot, linear noise removal is performed using 1800 m / s velocity information to eliminate the impact of noise on the effective reflection wave. After these steps are completed, dynamic movement correction (DMN) is performed. Since the strata in the central region are relatively flat, the DMN results in a flattened stratum, essentially matching the stratigraphic characteristics.

[0034] Step 103: Copy the acquired single shot and modify its coordinates. Copy the corrected single shot and modify the shot point coordinates for each shot. The distance between adjacent shots is 50 meters. Changing the shot point coordinates also changes the coordinates of the corresponding detector points.

[0035] Step 104 , superimposing well shots and vibroseis single shots with different coverage times, and analyzing the signal-to-noise ratio of the single shots with different coverage times.

[0036] The modified gun records are superimposed according to the coordinates to form a superimposed section, and are superimposed according to different coverage times.

[0037] Step 105: Find the well guns and vibroseis coverage times with the same signal-to-noise ratio, and use this method to obtain matching relationships on other surfaces.

[0038] from Figure 2 It can be seen that Figure 2 The figure shows the signal-to-noise ratio of well-shot coverage times at different coverage times, compared to the signal-to-noise ratio of 660 vibroseis data. The height of the bar represents the signal-to-noise ratio. As can be seen from the figure, the signal-to-noise ratio of 200 well-shot coverage times is almost equivalent to that of 660 vibroseis data, resulting in a 1:3 matching relationship between well-shot coverage times and vibroseis coverage times.

[0039] According to the above method, after superimposing the well gun and the controllable source single shot with different coverage times, the signal-to-noise ratio of the well gun and the controllable source with different coverage times is analyzed, so as to find the corresponding relationship between the coverage times of the well gun and the controllable source under the same signal-to-noise ratio under the surface conditions, that is, the matching relationship. This method can effectively consider the matching relationship between the well gun and the controllable source under different near-surface conditions, effectively improve the correctness of the selection of acquisition factors for deep targets, and lay the foundation for the reasonable selection of acquisition factors.

[0040] The following are several specific embodiments of the present invention:

[0041] Example 1

[0042] In a specific embodiment 1 of the present invention, the method for selecting the matching relationship between the well gun and the vibrator excitation parameters includes the following steps:

[0043] After analyzing the surface type of the work area, well shot and vibroseis single-shot tests were conducted on various surfaces. A range length of 14,000 meters was selected, with a trace spacing of 25 meters, and the shot point located in the center of the range. After the single-shot acquisition was completed, static correction was performed on the data to eliminate time differences caused by surface elevation differences.

[0044] Then, linear noise removal is performed. Because the high-speed layer interface produces a lot of linear secondary interference, which seriously affects the signal-to-noise ratio of a single shot, 1800m / s velocity information is used for linear removal to eliminate the impact of noise on the effective reflection wave.

[0045] After these steps are completed, dynamic movement correction (DMN) processing is performed. Since the strata in the central region are relatively flat, DMN results in a flattened stratum, essentially matching the stratigraphic characteristics. Each shot after DMN is copied. For example, 500 shots are copied for a well shot, while 1200 shots are copied for a vibroseis shot, recorded as S1, S2, S3, and so on. The shot point coordinates for each shot are modified, with the distance between adjacent shots being 50 meters. For example, the coordinates for shot S1 are 7000, for shot S2 7050, for shot S3 7100, and so on. As the shot point coordinates are modified, the coordinates of the corresponding receiver points are also modified. For example, the coordinates of each receiver point for S2 are S1 + 50, the coordinates of each receiver point for S3 are S1 + 100, and so on.

[0046] The modified shot records are then stacked according to coordinates to form a stacked profile. This stacking is then repeated for different overlay times, such as 100, 150, 200, and so on. Following this method, after stacking well and vibroseis shots at different overlay times, the signal-to-noise ratios of the well and vibroseis shots at different overlay times are analyzed. This allows the correspondence between the overlay times for well and vibroseis shots under the same surface conditions, i.e., the matching relationship. For example, in a farmland area, the signal-to-noise ratio of 200 well shots is 2.1, which is the same as the signal-to-noise ratio of 500 vibroseis shots, so the matching relationship between well and vibroseis shots in the farmland area is 2:5.

[0047] Example 2

[0048] In the second embodiment of the present invention, the method for selecting the matching relationship between the well gun and the vibrator excitation parameters includes the following steps:

[0049] After analyzing the surface type of the work area, well shot and vibroseis single-shot tests were conducted on various surfaces. A range length of 12,000 meters was selected, with a trace spacing of 50 meters, and the shot point located in the center of the range. After the single-shot acquisition was completed, static correction was performed on the data to eliminate time differences caused by surface elevation differences.

[0050] Then, linear noise removal is performed. Because the high-speed layer interface produces a lot of linear secondary interference, which seriously affects the signal-to-noise ratio of a single shot, 1850m / s velocity information is used for linear removal to eliminate the impact of noise on the effective reflection wave.

[0051] After these steps are completed, dynamic movement correction (DMN) processing is performed. Since the strata in the central region are relatively flat, DMN results in a flattened formation, essentially matching the stratigraphic characteristics. Each shot after DMN is replicated. For example, 400 shots are replicated for a well shot, while 1000 shots are replicated for a vibroseis shot, recorded as S1, S2, S3, and so on. The shot point coordinates for each shot are modified, with the distance between adjacent shots being 50 meters. For example, the coordinates for shot S1 are 6000, for shot S2 6050, for shot S3 6100, and so on. As the shot point coordinates are modified, the coordinates of the corresponding receiver points are also modified. For example, the coordinates of each receiver point for S2 are S1 + 50, the coordinates of each receiver point for S3 are S1 + 100, and so on.

[0052] The modified shot records are then stacked according to coordinates to form a stacked profile. This stacking is then repeated with varying overlay times, such as 200, 250, 300, and so on. Following this method, after stacking well and vibroseis shots at varying overlay times, the signal-to-noise ratios of these overlay times are analyzed. This allows the relationship between the overlay times for well and vibroseis shots under the same surface conditions, i.e., the matching relationship, or "matching relationship." For example, in a farmland area, the signal-to-noise ratio for 200 well shots is 2.2, which is the same as the 2.2 for 500 vibroseis shots. Therefore, the matching relationship between well and vibroseis shots in the farmland area is 2:5.

[0053] Example 3

[0054] In the third embodiment of the present invention, the method for selecting the matching relationship between the well gun and the vibrator excitation parameters includes the following steps:

[0055] After analyzing the surface type of the work area, well shot and vibroseis single-shot tests were conducted on various surfaces. A range length of 11,000 meters was selected, with a trace spacing of 40 meters, and the shot point located in the center of the range. After the single-shot acquisition was completed, static correction was performed on the data to eliminate time differences caused by surface elevation differences.

[0056] Next, linear noise removal is performed. Because high-speed layer interfaces generate significant linear secondary interference, significantly impacting the signal-to-noise ratio of a single shot, linear noise removal is performed using 1900 m / s velocity information to eliminate the impact of noise on the effective reflection wave. After these steps are completed, dynamic correction (DNO) processing is performed. Since the strata in the central region are relatively flat, DNO results flatten the strata, essentially matching the stratigraphic characteristics. The DNO-corrected single shot is replicated. For example, for a well shot, 350 shots are replicated, while for a vibroseis shot, 900 shots are replicated, denoted as S1, S2, S3, and so on. The shot point coordinates of each shot are modified, with the distance between adjacent shots being 50 m. For example, the coordinates of shot S1 are 5000, S2 are 5050, S3 are 5100, and so on. After the coordinates of the shot point change, the coordinates of the corresponding detection points will also change. For example, the coordinates of the detection points of S2 are based on S1 + 50, the coordinates of the detection points of S3 are based on S1 + 100... and so on.

[0057] The modified gun records are superimposed according to the coordinates to form a superimposed profile, and the superposition is performed according to different coverage times, such as 50 times, 100 times, 150 times... and so on.

[0058] Following this method, after stacking well and vibroseis shots at different coverage times, the signal-to-noise ratios of each are analyzed. This allows the corresponding relationship between the coverage times for well and vibroseis shots under the same signal-to-noise ratio conditions, i.e., the matching relationship, to be found. For example, in a farmland area, the signal-to-noise ratio of 100 well shots is 1.2, which is the same as the signal-to-noise ratio of 300 vibroseis shots, meaning the matching relationship between well and vibroseis shots in the farmland area is 1:3.

[0059] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art may modify the technical solutions described in the aforementioned embodiments or substitute equivalents for some of the technical features therein. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

[0060] Except for the technical features described in the specification, all other technical features are known technologies to those skilled in the art.

Claims

1. A method for selecting the matching relationship between well gun and vibroseis excitation parameters, characterized in that: The method for selecting the matching relationship between the well gun and the vibrator excitation parameters includes: Step 1: Divide the surface of the work area into sections and conduct well shot and vibroseis single shot tests respectively; Step 2: Perform static correction and denoising on the single shot; Step 3: Copy the processed single shot and modify the coordinate information; Step 4: Superimpose different coverage times of well shot and vibroseis single shot respectively, and analyze the signal-to-noise ratio of the single shot with different coverage times; Step 5: Find the well gun and vibroseis coverage times with the same signal-to-noise ratio, and use the same method to obtain matching relationships on other surfaces.

2. The method for selecting the matching relationship between well gun and vibroseis excitation parameters according to claim 1, characterized in that: In step 1, the surface conditions of the work area are divided into types, and a representative place is selected as a test point for each type of surface.

3. The method for selecting the matching relationship between well gun and vibroseis excitation parameters according to claim 2, characterized in that: In step 1, well gun and vibroseis single shot acquisition tests are carried out at each test point, with the well gun and vibroseis firing one shot each, and the shot point is located in the middle of the arrangement.

4. The method for selecting the matching relationship between well gun and vibroseis excitation parameters according to claim 1, characterized in that: In step 2, after the single-shot acquisition is completed, the data needs to be statically corrected to eliminate the time difference problem caused by the surface height difference.

5. The method for selecting the matching relationship between well gun and vibroseis excitation parameters according to claim 4, characterized in that: In step 2, after static correction, linear noise removal is performed. Because the high-speed layer interface will produce more linear secondary interference, which seriously affects the signal-to-noise ratio of a single shot, a certain velocity information is used for linear removal to eliminate the impact of noise on the effective reflection wave.

6. The method for selecting the matching relationship between well gun and vibroseis excitation parameters according to claim 5, characterized in that: In step 2, the 1800 m / s velocity information is used for linear removal to eliminate the influence of noise on the effective reflected wave.

7. The method for selecting the matching relationship between well gun and vibroseis excitation parameters according to claim 6, characterized in that: In step 2, after linear noise removal, dynamic correction is performed. In relatively flat areas of the formation, the formation is flattened after dynamic correction, which basically conforms to the formation characteristics.

8. The method for selecting the matching relationship between well gun and vibroseis excitation parameters according to claim 1, characterized in that: In step 3, the single shot after dynamic correction is copied and the shot point coordinates of each shot are modified. When the coordinates of the shot point are changed, the coordinates of the corresponding detection points are also changed.

9. The method for selecting the matching relationship between well gun and vibroseis excitation parameters according to claim 1, characterized in that: In step 4, the modified shot records are superimposed according to the coordinates to form a superimposed section, and the superposition is performed according to different coverage times.

10. The method for selecting the matching relationship between well gun and vibroseis excitation parameters according to claim 1, characterized in that: In step 5, after superimposing the well gun and the vibrator single shot with different coverage times, the signal-to-noise ratios of the well gun and the vibrator with different coverage times are analyzed, so as to find the corresponding relationship between the coverage times of the well gun and the vibrator with the same signal-to-noise ratio under the surface conditions, that is, the matching relationship.

11. A selection system for matching the excitation parameters of well guns and vibroseis for different near-surface conditions, characterized by: The selection system for the matching relationship between well guns and controllable vibrator excitation parameters under different near-surface conditions adopts the selection method for the matching relationship between well guns and controllable vibrator excitation parameters described in any one of claims 1-10 to consider the matching relationship between well guns and controllable vibrators under different near-surface conditions to select acquisition factors for deep targets.

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