A method for solving the static correction problem of two-dimensional survey lines using three-dimensional surface survey points

Abstract

A method for solving the static correction problem of two-dimensional survey lines using three-dimensional surface survey points belongs to the field of near-surface static correction technology for seismic data processing. For the first time, this method uses three-dimensional surface survey points within the work area to establish a field near-surface model. Two-dimensional static corrections are calculated using this three-dimensional model. Three-dimensional micro-logging and small refraction are used to constrain the inversion of the two-dimensional tomographic model, resulting in higher accuracy in the calculated tomographic static corrections. This method also achieves excellent results for the two-dimensional closure problem of multiple survey lines. Designed based on actual seismic data and the seismic work area, this method features simple steps and is easy to use. Simply leveraging existing methods can quickly achieve the final function, saving significant funds and personnel. Most importantly, it shortens the processing cycle and doubles the efficiency of the static correction process.

Description

Technical Field

[0001] The invention belongs to the technical field of near-surface static correction in seismic data processing, and in particular relates to a method for solving the static correction problem of a two-dimensional survey line by utilizing three-dimensional surface survey network points. Background Art

[0002] Static correction is a crucial step in ensuring the accuracy of seismic data processing and is one of the most important issues to address in seismic data processing. Static correction errors not only affect the signal-to-noise ratio (SNR) but also affect data resolution by preventing the data from being stacked in phase. To improve velocity picking accuracy, a combination of velocity spectra, moving average gathers, and variable-velocity stack profiles is employed to accurately determine stacking velocities. As the saying goes, "Solving static correction effectively solves almost half the problems in seismic exploration." This statement clearly illustrates the importance of static correction in seismic exploration. Failure to properly address static correction makes it difficult to image reflections in horizontal stacks, which can lead to structural morphology errors and hinder structural interpretation. Furthermore, the accuracy of static correction also affects the SNR of seismic data and can even affect data resolution, resulting in errors in reservoir description and attribute analysis. Furthermore, poorly addressed static correction can also compromise the imaging performance of prestack depth migration.

[0003] Old seismic data often present various issues, the most prominent of which is near-surface static correction. Because the data were collected so early, much of the information is incomplete. Therefore, leveraging existing data for reprocessing and achieving superior results is paramount. The most significant issue is resolving the static correction issue. Due to this missing information, commonly used static correction calculation methods are inaccurate and prone to creating false structures, significantly complicating subsequent interpretation. Therefore, an accurate and efficient static correction calculation method is urgently needed to address this issue. Summary of the Invention

[0004] In order to solve the above problems, the present invention proposes a method for solving the static correction problem of a two-dimensional survey line using a three-dimensional surface survey network, comprising the following steps:

[0005] S1. First, you need to collect the electronic sps files of all 2D survey line grids, obtain the distribution range of the 2D survey lines, as well as the elevation and well depth information, and collect the 3D surface survey point files involved in the work area;

[0006] S2. Load the 2D electronic sps file of the entire area and the 3D surface survey point file involved in the work area through the near-surface acquisition and processing system;

[0007] S3. Use the 3D surface survey point file to build a near-surface structural model, interpret the micro-well logging or small refraction curve, perform stratification, and then smooth it to make the structural model more reasonable.

[0008] S4. Use the 3D model to calculate the static correction of the entire area, and then use the sps file of the 2D survey line to reflect it and apply it to the actual 2D survey line;

[0009] S5. Separate the high and low frequencies of the two-dimensional line static correction data as needed, and output the required low-frequency data text;

[0010] S6. Establishing an initial model by picking the first arrival of the two-dimensional line;

[0011] S7, loading the three-dimensional surface survey point data to perform constrained tomography inversion iteration on the initial model to ensure that the error values ​​of picking the first arrival and inverting the first arrival converge to a reasonable threshold value;

[0012] S8. Determine the high-speed layer top, calculate the tomographic static correction, and finally perform high- and low-frequency separation on the tomographic amount, and output the final high-frequency component static correction text file.

[0013] Furthermore, in step S1, all three-dimensional survey points within the two-dimensional survey line are collected to ensure the accuracy of the three-dimensional model.

[0014] Furthermore, in step S2, the two-dimensional sps file and the three-dimensional survey point file are ensured to be accurate during the loading process.

[0015] Furthermore, in step S3, the three-dimensional survey point file is interpreted to ensure the rationality of the model.

[0016] Furthermore, before step S4, it is necessary to ensure that the accuracy of the three-dimensional model meets the requirements. In step S4, the static correction amount of the three-dimensional range is first calculated and then reflected and applied to the two-dimensional survey line.

[0017] Furthermore, in step S5, the calculated two-dimensional field static correction amount is separated into high and low frequencies, and the low frequency amount is output.

[0018] Furthermore, in step S6, the first arrival of the two-dimensional line is picked.

[0019] Furthermore, in step S7, the three-dimensional surface survey points are used to constrain the two-dimensional line tomography inversion.

[0020] Furthermore, in step S8, a tomographic static correction calculation is performed, and then the high-frequency component is extracted and output.

[0021] The beneficial effects of the present invention are as follows: the present invention is designed in combination with actual seismic data and seismic work areas, and is implemented jointly by using near-surface model software and static correction software. Relatively speaking, the steps are simple and easy to operate. The final function can be quickly realized by simply making good use of the existing software. A large amount of money and personnel can be saved, and the most important thing is to shorten the processing cycle, which can double the efficiency of the static correction link. It has an immeasurable positive effect on the reprocessing of a large number of two-dimensional lines in the old areas of the Jilin Oilfield. This method is highly practical and has a wide range of applications. It can produce significant economic and social benefits in terms of reducing costs and increasing efficiency, or have a significant impact on the field of strategic advance reserve technology. It is expected to be transformed and create benefits within 1 year. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 Shown is a two-dimensional survey line distribution range diagram in an example of the present invention;

[0023] Figure 2 Shown is a distribution diagram of three-dimensional surface survey points in a two-dimensional survey line grid in an example of the present invention;

[0024] Figure 3 Shown is a two-dimensional low-frequency component static correction plane distribution diagram calculated in an example of the present invention;

[0025] Figure 4 Shown is a diagram of a near-surface structure model inverted using three-dimensional micro-well logging and small refraction constraints in an example of the present invention;

[0026] Figure 5 Shown is a two-dimensional high-frequency component static correction plane distribution diagram calculated in an example of the present invention.

[0027] Figure 6 Shown are superimposed cross-sectional renderings before and after static correction is applied in an example of the present invention. DETAILED DESCRIPTION

[0028] To make the technical means and objectives of the present invention easier to understand, the present invention is further described below in conjunction with specific embodiments. A method for solving the static correction problem of a two-dimensional survey line using three-dimensional surface survey points includes the following steps:

[0029] S1. First, you need to collect the electronic sps files of all 2D survey line grids, obtain the distribution range of the 2D survey lines, as well as the elevation and well depth information, and collect the 3D surface survey point files involved in the work area;

[0030] S2. Load the 2D electronic sps file of the entire area and the 3D surface survey point file involved in the work area through the near-surface acquisition and processing system;

[0031] S3. Use the 3D surface survey point file to build a near-surface structural model, interpret the micro-well logging or small refraction curve, perform stratification, and then smooth it to make the structural model more reasonable.

[0032] S4. Use the 3D model to calculate the static correction of the entire area, and then use the sps file of the 2D survey line to reflect it and apply it to the actual 2D survey line;

[0033] S5. Separate the high and low frequencies of the two-dimensional line static correction data as needed, and output the required low-frequency data text;

[0034] S6. Establishing an initial model by picking the first arrival of the two-dimensional line;

[0035] S7, loading the three-dimensional surface survey point data to perform constrained tomography inversion iteration on the initial model to ensure that the error values ​​of picking the first arrival and inverting the first arrival converge to a reasonable threshold value;

[0036] S8. Determine the high-speed layer top, calculate the tomographic static correction, and finally perform high- and low-frequency separation on the tomographic amount, and output the final high-frequency component static correction text file.

[0037] Reference Figure 1 , Step 1: Load the sps file and data preparation of the table file

[0038] This paper uses 148 two-dimensional line data from the western slope from 1988 to 2005 as an example;

[0039] The main requirements are standard SPS file formats and standard loadable surface files. Due to data collection, some survey lines need to convert electronic shift reports to SPS files. At the same time, all SPS files must be QC-ed to ensure data usability.

[0040] Step 2: If Figure 2 As shown, fully load all 2D line sps files and 3D surface survey point files within the scope of the project, ensure that there are no errors during the loading process, and perform quality control through plane monitoring. Any problematic data should be modified.

[0041] Step 3: If Figure 3 As shown in the figure, using the three-dimensional surface survey points, the static correction value within the work area is first calculated, and then the high and low frequencies are separated to output the static correction low-frequency component of the two-dimensional survey line. This quantity has a certain mirror relationship with the surface elevation.

[0042] Step 4: If Figure 4 As shown in the figure, 3D micro-logging and a small refraction grid are used to constrain the initial model when calculating high-frequency tomographic quantities, ensuring the accuracy of the inversion model. It can be seen that the velocity in the low-deceleration zone is more accurate, which is beneficial for defining the high-velocity layer top interface.

[0043] Step 5: Then calculate the tomographic static correction by replacing the velocity and the final reference plane and combining the refraction residual, and extract its high-frequency components, such as Figure 5 shown.

[0044] Step 6: Combine the low-frequency component and the high-frequency component in the final application to achieve the purpose of solving the static correction problem and ensure the closure of the subsequent two-dimensional survey line. Figure 6 shown.

[0045] The method developed above utilizes a 3D surface survey network to solve the static correction problem of 2D survey lines. This method, for the first time, utilizes 3D surface survey points within the work area to establish a near-surface model in the field. Calculating 2D statics using the 3D model solves the problem of static correction issues often hindered by the lack of data collected when the 2D survey lines were constructed early. Furthermore, 3D micro-logging and small refraction constraints are used to constrain the 2D tomographic model inversion, resulting in higher accuracy in the calculated tomographic statics. It also achieves excellent results in solving the 2D closure problem of multiple survey lines. This method was designed based on actual seismic data and the seismic work area. The steps are relatively simple and easy to use. Simply leveraging existing methods, the final function can be quickly achieved. This method saves significant funds and personnel, and most importantly, shortens the processing cycle, doubling the efficiency of the static correction process. It has an immeasurable positive impact on the reprocessing of a large number of 2D lines in the old oilfields of Jilin Oilfield. This method is highly practical and has a wide range of applications. It can generate significant economic and social benefits in terms of cost reduction and efficiency improvement, and may have a significant impact on the field of strategic advance reserve technology. It is expected to be commercially effective within one year.

[0046] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, i.e., they may be located in one location or distributed across multiple network units. Some or all of the modules may be selected based on actual needs to achieve the objectives of the present embodiment. Persons of ordinary skill in the art will be able to understand and implement the present invention without inventive effort.

[0047] Through the description of the above embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus a necessary general hardware platform, or of course, by hardware. Based on this understanding, the essence of the above technical solution or the part that contributes to the relevant technology can be embodied in the form of a software product. The computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a magnetic disk, an optical disk, etc., and includes a number of instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or certain parts of the embodiment.

[0048] To solve the static correction problem, we need to do well in two aspects.

[0049] First, calculate the short-wavelength static correction; this is usually caused by drastic changes in the near-surface, which affects the superposition effect. Usually, the first-arrival tomographic inversion method is used to solve it.

[0050] The second is to calculate long-wavelength static corrections; these corrections are caused by near-surface gradients, and their impact is primarily on structural morphology, with little influence on the stacking effect. Long-wavelength static corrections are typically addressed through field micro-logging and small refraction.

[0051] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed in the present invention, who makes equivalent replacements or changes based on the technical solutions and concepts of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A method for solving the static correction problem of a two-dimensional survey line using three-dimensional surface survey points, characterized in that: The following steps are involved: S1. First, you need to collect the electronic sps files of all 2D survey line grids, obtain the distribution range of the 2D survey lines, as well as the elevation and well depth information, and collect the 3D surface survey point files involved in the work area; S2. Load the 2D electronic sps file of the entire area and the 3D surface survey point file involved in the work area through the near-surface acquisition and processing system; S3. Use the 3D surface survey point file to build a near-surface structural model, interpret the micro-well logging or small refraction curve, perform stratification, and then smooth it to make the structural model more reasonable. S4. Use the 3D model to calculate the static correction of the entire area, and then use the sps file of the 2D survey line to reflect it and apply it to the actual 2D survey line; S5. Separate the high and low frequencies of the two-dimensional line static correction data as needed, and output the required low-frequency data text; S6. Establishing an initial model by picking the first arrival of the two-dimensional survey line; S7, loading the three-dimensional surface survey point data to perform constrained tomography inversion iteration on the initial model to ensure that the error values ​​of picking the first arrival and inverting the first arrival converge to a reasonable threshold value; S8. Determine the high-speed layer top, calculate the tomographic static correction, and finally perform high- and low-frequency separation on the tomographic amount, and output the final high-frequency component static correction text file.

2. The method for solving the static correction problem of a two-dimensional survey line using three-dimensional surface survey points according to claim 1, characterized in that: In step S1, all three-dimensional survey points within the two-dimensional survey line are collected to ensure the accuracy of the three-dimensional model.

3. The method for solving the static correction problem of a two-dimensional survey line using three-dimensional surface survey points according to claim 1, characterized in that: In step S2, the two-dimensional sps file and the three-dimensional survey point file are ensured to be accurate during the loading process.

4. The method for solving the static correction problem of a two-dimensional survey line using three-dimensional surface survey points according to claim 1, characterized in that: In step S3, the three-dimensional survey point file is interpreted to ensure the rationality of the model.

5. The method for solving the static correction problem of a two-dimensional survey line using three-dimensional surface survey points according to claim 1, characterized in that: Before step S4, it is necessary to ensure that the accuracy of the three-dimensional model meets the requirements. In step S4, the static correction amount of the three-dimensional range is first calculated and then reflected and applied to the two-dimensional survey line.

6. The method for solving the static correction problem of a two-dimensional survey line using three-dimensional surface survey points according to claim 1, characterized in that: In step S5, the calculated two-dimensional field static correction amount is separated into high and low frequencies, and the low frequency amount is output.

7. The method for solving the static correction problem of a two-dimensional survey line using three-dimensional surface survey points according to claim 1, characterized in that: In step S6, the first arrival of the two-dimensional survey line is picked.

8. The method for solving the static correction problem of a two-dimensional survey line using three-dimensional surface survey points according to claim 1, characterized in that: In step S7, the three-dimensional surface survey points are used to constrain the two-dimensional survey line tomographic inversion.

9. The method for solving the static correction problem of a two-dimensional survey line using three-dimensional surface survey points according to claim 1, characterized in that: In step S8, a tomographic static correction calculation is performed, and then high-frequency components are extracted and output.

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