OVT sheet division method for subdivision surface element observation system
By calculating the ratio of the coverage times of the conventional observation system and the size of the subdivided bin, and combining the maximum offset, the OVT slices are re-divided. This solves the problem of many holes in the OVT slices in the subdivided bin observation system, improves the imaging effect and the azimuth information retention.
Patent Information
- Application Number
- CN202410422015.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-09
- Publication Date
- 2025-10-14
AI Technical Summary
The existing OVT slice division method for the subdivided surface element observation system results in the number of OVT slices far exceeding the actual need, resulting in many holes and affecting the subsequent regularization and offset imaging effects.
By calculating the coverage times and subdivision bin size ratio of the conventional observation system and combining the maximum offset, the OVT slices are re-divided in non-vertical and vertical scales. A new OVT slice division method is adopted to reduce voids and improve imaging effects.
It effectively reduces the voids in the OVT slices, improves the imaging effect of seismic data, preserves the azimuth information, and provides a practical processing flow for the subdivision bin observation system.
Smart Images
Figure CN120779458A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of OVT domain prestack time migration imaging, and in particular relates to an OVT slice partitioning method for a subdivided bin observation system. Background Art
[0002] OVT (wide azimuth vector migration) domain processing technology is one of the current research hotspots in seismic data processing and interpretation. Its main advantages are: OVT gathers have good consistency and can truly preserve the original data acquisition characteristics; OVT domain migration can retain azimuth information; OVT domain migration has good amplitude characteristics, which is conducive to inversion.
[0003] The subdivided bin observation system refers to an irregular observation system designed to achieve small bin processing during the acquisition process, thereby improving the accuracy of seismic data. Its main feature is that when the track spacing or shot point spacing is large, sufficiently small "sub-bins" can still be obtained. Appropriate bin processing can be selected according to processing needs.
[0004] In conventional observation systems, the shot line spacing is a multiple of the receiver point spacing, and the receiver line spacing is a multiple of the shot point spacing. In subdivided bin observation systems, the shot line spacing and receiver point spacing, as well as the receiver line spacing and shot point spacing, are not integer multiples. Therefore, when conventional OVT domain processing is used to divide OVT slices, the OVT slice scale is equal to twice the shot line spacing multiplied by twice the receiver line spacing. The actual number of divided OVT slices will far exceed the theoretical number of OVT slices, and some OVT slices will have many holes, which will have an adverse effect on subsequent regularization and migration imaging. Therefore, for subdivided bin observation systems, it is necessary to change traditional thinking and invent new OVT slice division methods. Summary of the Invention
[0005] The object of the present invention is to provide an OVT slice partitioning method for a subdivided facet observation system, so as to solve the problem of OVT slice holes caused by the OVT slice partitioning method in the prior art.
[0006] To solve the above technical problems, the present invention provides an OVT slice partitioning method for a subdivided surface element observation system, comprising the following steps:
[0007] 1) Calculate the coverage times of the OVT slice in the non-vertical and vertical directions according to the conventional observation system; calculate the ratio of the non-vertical subdivision bin size to the conventional bin size, and multiply it by the coverage times of the OVT slice in the non-vertical directions according to the conventional observation system to obtain the coverage times of the OVT slice in the non-vertical directions according to the subdivision bin observation system F. x Calculate the ratio of the longitudinal subdivision bin size to the conventional bin size, and multiply it by the number of longitudinal coverage of the OVT slice divided by the conventional observation system to obtain the number of longitudinal coverage of the OVT slice divided by the subdivision bin observation system F y ;
[0008] 2) Calculate the non-longitudinal maximum offset and F x The ratio of the OVT slices is obtained by dividing the OVT slices in the non-vertical direction by the subdivided surface element observation system, and the longitudinal maximum offset and F are calculated. y The ratio of 1 to 2 is used to obtain the vertical scale IOY of the OVT slice divided by the subdivided surface element observation system;
[0009] 3) Divide the OVT slices according to the calculated IOX and IOY.
[0010] Furthermore, according to the conventional observation system, the number of OVT slices covered in the non-longitudinal direction is the number of single-line tracks multiplied by the track spacing and then divided by twice the shot line spacing.
[0011] Furthermore, according to the conventional observation system, the number of times the OVT slice covers in the longitudinal direction is half of the number of receiving lines.
[0012] Furthermore, the non-longitudinal regular bin size is half of the receiving track pitch.
[0013] Furthermore, the longitudinal regular bin size is half of the excitation point pitch.
[0014] Furthermore, the non-longitudinal maximum offset is the product of the track spacing and the number of single-line tracks.
[0015] Furthermore, the longitudinal maximum offset is the product of the receiving line distance and the number of receiving lines.
[0016] The beneficial effects are as follows: the present invention is an improved invention creation. The present invention first calculates the non-vertical and vertical coverage times of the OVT slices divided by the conventional observation system, then calculates the non-vertical and vertical coverage times of the OVT slices divided by the subdivided bin observation system based on the size relationship between the non-vertical and vertical subdivided bins and the conventional bins, and then calculates the non-vertical and vertical coverage times of the OVT slices divided by the subdivided bin observation system based on the non-vertical and vertical maximum offsets. Then, the scales for dividing the OVT slices by the subdivided bin observation system in the non-vertical and vertical directions are obtained. The OVT slices are then divided using the non-vertical and vertical scales for dividing the OVT slices by the subdivided bin observation system, thereby reasonably expanding the bin division scale and reducing the voids in the OVT slices. This avoids the situation where the number of OVT slices far exceeds the coverage times when the conventional OVT slice division method is applied to the subdivided bin observation system. This effectively solves the problem that the conventional OVT slice division method is not applicable to the subdivided bin observation system and has an adverse effect on subsequent regularization and migration imaging, thereby improving the imaging effect of seismic data. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 It is a flow chart of the OVT slice partitioning method for the subdivided facet observation system of the present invention;
[0018] Figure 2is a schematic diagram of an observation system used in an embodiment of the present invention;
[0019] Figure 3-1 、 Figure 3-2 The reflection point distribution diagrams in the embodiment of the present invention are respectively divided according to conventional OVT slices and the method of the present invention;
[0020] Figure 4-1 、 Figure 4-2 Schematic diagram of a single cross section according to conventional OVT slice division and the method of the present invention in an embodiment of the present invention;
[0021] Figure 5-1 、 Figure 5-2 Schematic diagram of the reflection surface element and single cross section of the OVT sheet after regularization according to the method of the present invention in an embodiment of the present invention. DETAILED DESCRIPTION
[0022] The main process of the OVT slice partitioning method for a subdivided bin observation system of the present invention is as follows: first, the number of times the OVT slice is partitioned in the non-longitudinal and longitudinal directions according to the conventional observation system is calculated. Then, the number of times the OVT slice is partitioned in the non-longitudinal and longitudinal directions according to the subdivided bin observation system is calculated by using the relationship between the size of the non-longitudinal and longitudinal subdivided bins and the size of the conventional bins, as well as the number of times the OVT slice is partitioned in the non-longitudinal and longitudinal directions according to the subdivided bin observation system, is obtained. Then, the scales of the OVT slice in the non-longitudinal and longitudinal directions according to the subdivided bin observation system are obtained by combining the non-longitudinal and longitudinal maximum offsets. The OVT slice is partitioned using the non-longitudinal and longitudinal scales according to the subdivided bin observation system for subsequent regularization and offset processing. This method effectively solves the problem that traditional OVT slice partitioning is not applicable to subdivided bin observation systems, providing a practical method for OVT domain processing of subdivided bin observation systems.
[0023] In order to make the objectives, technical solutions and advantages of the present invention more clear, the present invention is further described in detail below with reference to the accompanying drawings.
[0024] The present invention is an embodiment of an OVT slice partitioning method for a subdivided facet observation system, and its specific implementation process is as follows: Figure 1 As shown:
[0025] Step 1: Obtain the OVT domain seismic data collected by the subdivided bin observation system of a certain block and import it into the seismic data processing software for processing.
[0026] Step 2: Analyze the subdivision surface element observation system, as shown in Table 1 and Figure 2 As shown, the track distance D is 50 meters, the receiving line distance (i.e. detection line distance) R x For 100 meters, the number of receiving lines R nThere are 32 single-line channels, n is 128, and the excitation point distance (i.e., shot point distance) S d is 80 meters, and the gun line distance S s It is 80 meters.
[0027] Table 1
[0028]
[0029] Step 3: Calculate the number of times N that the OVT slices are covered in the non-vertical direction according to the conventional observation system. x and the number of vertical coverage N y , the calculation formulas are as follows:
[0030]
[0031]
[0032] Step 4: Calculate the ratio of the non-longitudinal subdivision bin size to the conventional bin size (half of the receiving track pitch), and multiply it by the number of times the OVT slice is covered in the non-longitudinal direction by the conventional observation system to obtain the number of times the OVT slice is covered in the non-longitudinal direction by the subdivided bin observation system; calculate the ratio of the longitudinal subdivision bin size to the conventional bin size (half of the excitation point pitch), and multiply it by the number of times the OVT slice is covered in the longitudinal direction by the conventional observation system to obtain the number of times the OVT slice is covered in the longitudinal direction by the subdivided bin observation system. The following is an example of a subdivided bin observation system with 10×10 subdivision bins. M x =M y =10, that is:
[0033]
[0034]
[0035] Where, F x and F y The coverage times of OVT slices in non-vertical and vertical directions are divided by subdivided facet observation system respectively.
[0036] Step 5: Calculate the ratio of the non-longitudinal maximum offset to the number of times the OVT slice is covered in the non-longitudinal direction by the subdivided bin observation system to obtain the scale of the OVT slice in the non-longitudinal direction by the subdivided bin observation system. Calculate the ratio of the longitudinal maximum offset to the number of times the OVT slice is covered in the longitudinal direction by the subdivided bin observation system to obtain the scale of the OVT slice in the longitudinal direction by the subdivided bin observation system. The specific calculation formula is as follows:
[0037]
[0038]
[0039] Where IOX and IOY are the division scales of the OVT slice in the non-vertical and vertical directions according to the subdivided surface observation system, respectively.
[0040] Step 6: Divide the OVT slices according to the non-vertical and vertical division scales of the subdivided facet observation system obtained in step 5.
[0041] Step seven: perform subsequent regularization processing.
[0042] The reflection point distribution diagrams are respectively divided according to the conventional observation system OVT slice division and the method of the present invention. Figure 3-1 、 3-2 As shown, the schematic diagram of the single cross-section is divided according to the conventional observation system OVT slice and the method of the present invention. Figure 4-1 、 4-2 As shown, the schematic diagram of the reflection surface element and single cross section of the OVT sheet after regularization according to the method of the present invention is as follows Figure 5-1 、 Figure 5-2 As shown in these figures, it can be seen that compared with the methods in the prior art, the method of the present invention can effectively reduce the voids in the OVT sheet.
[0043] In summary, the OVT slice division method for the subdivided surface element observation system of the present invention can well realize the OVT domain processing of the subdivided surface element observation system, and reduces the problem of OVT slices far exceeding the coverage number when the subdivided surface element observation system is processed in the conventional OVT domain. The OVT slice division method of the present invention avoids the phenomenon that there are many holes in the OVT slices, which has an adverse effect on subsequent regularization and migration imaging, improves the migration imaging effect, and retains the azimuth information of the seismic data, providing a practical processing flow for the OVT domain processing of the subdivided surface element observation system.
[0044] While specific embodiments have been described above, the present invention is not limited to the described embodiments. The fundamental concept of the present invention lies in the aforementioned basic scheme. Based on the teachings of the present invention, those skilled in the art can devise various variations of models, formulas, and parameters without inventive effort. Changes, modifications, substitutions, and variations to the embodiments without departing from the principles and spirit of the present invention remain within the scope of protection of the present invention.
Claims
1. A method for partitioning OVT slices for a subdivided surface element observation system, characterized in that: The steps include: 1) Calculate the coverage times of the OVT slice in the non-vertical and vertical directions according to the conventional observation system; calculate the ratio of the non-vertical subdivision bin size to the conventional bin size, and multiply it by the coverage times of the OVT slice in the non-vertical directions according to the conventional observation system to obtain the coverage times of the OVT slice in the non-vertical directions according to the subdivision bin observation system F. x Calculate the ratio of the longitudinal subdivision bin size to the conventional bin size, and multiply it by the number of longitudinal coverage of the OVT slice divided by the conventional observation system to obtain the number of longitudinal coverage of the OVT slice divided by the subdivision bin observation system F y ; 2) Calculate the non-longitudinal maximum offset and F x The ratio of the OVT slices is obtained by dividing the OVT slices in the non-vertical direction by the subdivided surface element observation system, and the longitudinal maximum offset and F are calculated. y The ratio of 1 to 2 is used to obtain the vertical scale IOY of the OVT slice divided by the subdivided surface element observation system; 3) Divide the OVT slices according to the calculated IOX and IOY.
2. The OVT slice partitioning method for a subdivided surface element observation system according to claim 1, characterized in that: According to the conventional observation system, the number of OVT slices covered in the non-longitudinal direction is the number of single-line tracks multiplied by the track spacing and then divided by 2 times the shot line spacing.
3. The OVT slice partitioning method for a subdivided surface element observation system according to claim 1, characterized in that: According to the conventional observation system, the number of vertical coverage of the OVT slice is half of the number of receiving lines.
4. The OVT slice partitioning method for a subdivided surface element observation system according to claim 1, characterized in that: The non-longitudinal regular bin size is half of the receiving track pitch.
5. The OVT slice partitioning method for a subdivided surface element observation system according to claim 1, characterized in that: The longitudinal regular element size is half of the excitation point distance.
6. The OVT slice partitioning method for a subdivided surface element observation system according to any one of claims 1 to 5, characterized in that: The non-longitudinal maximum offset is the product of the track spacing and the number of single-line tracks.
7. The OVT slice partitioning method for a subdivided surface element observation system according to any one of claims 1 to 5, characterized in that: The maximum longitudinal offset is the product of the receiving line distance and the number of receiving lines.