A fusion tomography static correction processing method for multiple working areas
By fusing the first arrival time files of each single work area and performing tomographic inversion, the velocity model of the fused work area is generated and a unified tomographic static correction is calculated, which solves the problem of complex surface static correction and improves the signal-to-noise ratio of seismic data. , meeting the needs of precise exploration.
Patent Information
- Application Number
- CN202111266189.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2021-10-28
- Publication Date
- 2025-01-24
- Estimated Expiration
- 2041-10-28
AI Technical Summary
The static correction problem of complex surfaces affects the signal-to-noise ratio of seismic data. Especially in the continuous processing of multiple blocks, the tomographic static correction amount of different blocks in the overlapping area is inconsistent, resulting in a decrease in the signal-to-noise ratio of the fusion data and is unable to meet the detailed exploration. need.
By obtaining the first arrival time files of each single work area for calibration and merging, the fused first arrival time file is obtained, and the fused tomographic inversion is performed to generate the velocity model of the fused work area, and based on the low speed reduction zone and high speed layer in the reference work area The velocity distribution range is divided into high-speed top interfaces, and the tomographic static corrections are calculated uniformly.
Improving the accuracy of layers of the boundary of the boundary during the processing of single seismic data, solve the time difference caused by the differences in the difference between the layers of correction of different blocks in the reassessment area during multi -block fusion processing, and increase the signal -to -noise ratio of the seismic data. , Meet the demand for fine exploration.
Smart Images
Figure CN114047549B_ABST
Abstract
Description
Technical Field
[0001] The invention provides a fusion tomography static correction processing method for multiple working areas, belonging to the technical field of seismic data processing. Background Art
[0002] At present, major domestic oil fields have achieved good results in deep exploration and development of complex geological structures, showing good prospects for the exploration of complex oil and gas reservoirs. However, the static correction problem of complex surfaces has always been one of the difficult problems in seismic data processing, especially in surface morphology such as piedmont belts and loess plateaus. The surface undulations are large and the lateral velocity changes dramatically. There are serious static correction problems, which seriously affect the signal-to-noise ratio of seismic data and bring great challenges to seismic exploration, thus seriously restricting the progress of oil and gas exploration.
[0003] In the existing technology, elevation static correction often cannot solve the static correction problem of complex surfaces well. Usually, tomographic static correction is used to solve the static correction problem of a single work area. However, due to reasons such as data acquisition and first arrival picking, the boundary static correction problem of a single block of seismic data cannot be well solved. In addition, in the processing of multiple blocks, there is inconsistency in the tomographic static correction amount in the overlapping area of different blocks, which reduces the signal-to-noise ratio of the fused data and cannot meet the current fine exploration needs. Summary of the invention
[0004] The object of the present invention is to provide a fusion tomography static correction processing method for multiple working areas, which is used to solve the problem that the static correction problem of complex surface affects the signal-to-noise ratio of seismic data.
[0005] In order to achieve the above object, the present invention provides a fusion tomography static correction processing method for multiple working areas, comprising the following steps:
[0006] 1) Obtain the first arrival time file of each single work area for calibration, merge the calibrated first arrival time files to obtain a fused first arrival time file; the first arrival time file includes the geodetic coordinates and stake numbers of the shot points and the detection points in each single work area, the first arrival time, and the corresponding relationship between the shot points and the detection points;
[0007] 2) converting the geodetic coordinates of each shot point and the geodetic coordinates of the receiver point in the fusion first arrival time file into the coordinate system of the fusion work area, and then performing fusion tomography inversion to obtain the velocity model of the fusion work area; the fusion work area is composed of each single block work area;
[0008] 3) Obtain the velocity distribution range of the low-speed reduction zone and high-speed layer in the reference work area, divide the velocity model of the fusion work area, and obtain the high-speed top interface;
[0009] 4) Calculate the detection point static correction and shot point static correction of the fusion work area based on the high-speed top interface.
[0010] The first arrival time files of multiple single-block work areas are calibrated and merged to obtain a fused first arrival time file, and the geodetic coordinates of each shot point and detection point in the fused first arrival time file are converted to the coordinates of the fused work area, and then a fused tomographic inversion is performed to obtain a velocity model of the fused work area, and then the velocity model of the fused work area is divided according to the low-speed reduction zone and the high-speed layer velocity distribution range in the reference work area to obtain a high-speed top interface, and the tomographic static correction amount is uniformly calculated according to the high-speed top interface. The method of the present invention can improve the accuracy of the tomographic static correction of the boundary when processing single-block seismic data, and solve the time difference problem caused by the difference in tomographic static correction amount in the overlapping area of different blocks during multi-block fusion processing, thereby improving the signal-to-noise ratio of seismic data.
[0011] Furthermore, in the above method, in step 1), the first arrival time file of the corresponding work area is calibrated using the preset work area number.
[0012] The work area number is used to calibrate the first arrival time file, which is simple and convenient.
[0013] Furthermore, in the above method, in step 2), before performing fused tomographic inversion, the abnormal values in the fused first arrival time file are corrected.
[0014] Since the first arrival time is picked by machine, there may be inaccurate values. Therefore, the abnormal values are edited to correct the fused first arrival time file to improve the accuracy of the fused tomographic inversion.
[0015] Furthermore, in the above method, in step 2), micro-logging data of each single work area in the fusion work area is also obtained, and the micro-logging data is added to perform well constraints when performing fusion tomography inversion.
[0016] The measured micro-logging data is used to constrain the wells in the fused tomography inversion, which improves the accuracy of the fused tomography inversion.
[0017] Furthermore, in the above method, in step 3), the high-speed top interface is smoothed using a set small scale.
[0018] Small-scale smoothing of the high-speed top interface can eliminate the time difference caused by the overlap of work areas and improve the imaging effect.
[0019] Furthermore, in the above method, in step 4), the static correction amount of the detection point and the static correction amount of the shot point in the fusion work area are calculated by the following formula:
[0020]
[0021] T s =T g -t (2)
[0022] Where: T g is the static correction value of the detection point; T s is the static correction of the shot point; h1 and v1 are the thickness and velocity of the low-speed zone respectively; h2 and v2 are the thickness and velocity of the speed-reducing zone respectively; h d is the datum elevation; h g is the elevation of the high-speed top interface; v s is the filling speed; t is the well depth time.
[0023] The commonly used calculation formula for static correction is adopted to calculate the fusion static correction of the fusion work area, which is simple, convenient and has low calculation amount. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] Figure 1 It is a flowchart of a fusion tomography static correction processing method in an embodiment of the present invention;
[0025] Figure 2 When processing a single block, the method of the present invention is compared with the conventional method in cross section: Figure 2 (a) Schematic diagram of the cross section of a single block obtained using conventional static correction processing method; Figure 2 (b) is a schematic cross-sectional view obtained by using the fusion tomography static correction processing method of the present invention when processing a single block;
[0026] Figure 3 When multi-block fusion processing is performed, the method of the present invention is compared with the conventional method: Figure 3 (a) is a schematic diagram of the original cross section of a single block; Figure 3 (b) is a schematic diagram of the normal section obtained by using the conventional tomographic static correction processing method; Figure 3 (c) is a schematic diagram of the front section obtained by using the fusion tomography static correction processing method of the present invention. DETAILED DESCRIPTION
[0027] In order to make the purpose, 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 and embodiments.
[0028] Method Example:
[0029] The processing area of 3D seismic data in a certain area with favorable exploration is 146 km 2 The processing task is to improve the imaging accuracy of deep strata and provide high-quality seismic profiles for finding favorable fault blocks and fault lithology oil and gas reservoirs in the deep strata of the region. Figure 1 The process shown in the figure illustrates a fusion tomography static correction processing method for multiple working areas of the present invention, which includes the following steps:
[0030] 1) The first arrival time of each work area is picked up by the first arrival time picking software to obtain the first arrival time file of each three-dimensional work area, which includes the pile number and geodetic coordinates of each shot point and detection point in each work area, the first arrival time, and the corresponding relationship between the shot point and the detection point.
[0031] In order to ensure the uniqueness of the pile numbers of each shot point and detection point in the fused first arrival time file, the first arrival time files of each work area are calibrated before merging, which can ensure the uniqueness of the pile numbers of each shot point and detection point in the fused first arrival time file obtained after merging; when merging, the calibrated first arrival time files are imported into the first arrival time picking software to generate a fused first arrival time file.
[0032] In this embodiment, the first arrival time file of the corresponding work area is calibrated using the work area number.
[0033] 2) Perform coordinate conversion on the fused first arrival time file, specifically: convert the geodetic coordinates of each shot point and receiver point in the fused first arrival time file to the coordinate system of the fused work area to obtain the relative coordinates of each shot point and receiver point. Then perform fused tomographic inversion to obtain the velocity model of the fused work area.
[0034] Since machine picking is used when picking the first arrival time, there may be inaccurate values, so the outliers are edited to correct the fused first arrival time file.
[0035] In order to improve the accuracy of the velocity model in the fusion work area, micro-logging data of the shallow layer are also obtained. When performing fusion tomography inversion, the micro-logging data are added for well constraints.
[0036] 3) The stratigraphic characteristics of the fusion work area are generated according to the velocity model of the fusion work area, and the high-speed top interface of the fusion work area is divided according to the surface characteristics of the reference work area collected in the field: the low-velocity reduction zone and the high-speed layer velocity distribution range.
[0037] Since the geological features at the junction of the work areas are relatively complex when the work areas are merged, the high-speed top interface is also smoothed. If a large-scale smoothing is selected, the geological features will be blurred and difficult to identify. Therefore, a small-scale smoothing of the high-speed top interface can eliminate time differences and improve imaging effects while ensuring accuracy.
[0038] 4) Calculate the fusion static correction of the fusion work area by the following formula:
[0039]
[0040] T s =T g -t (2)
[0041] Where: T g is the static correction value of the detection point; T sis the static correction of the shot point; h1 and v1 are the thickness and velocity of the low-speed zone respectively; h2 and v2 are the thickness and velocity of the speed-reducing zone respectively; h d is the datum elevation; h g is the elevation of the high-speed top interface; v s is the filling speed; t is the well depth time.
[0042] The obtained fusion static correction value is compared with the tomographic static correction value of a single work area for quality control.
[0043] like Figure 2 As shown in (a) and (b), when processing a single block, the method of the present invention can effectively improve the accuracy of the static correction value at the block boundary, and improve the imaging accuracy and signal-to-noise ratio.
[0044] like Figure 3 As shown in (a), (b), and (c), when multiple blocks are fused, the method of the present invention can effectively improve the accuracy of static correction in the overlapping area of the blocks, improve imaging accuracy and signal-to-noise ratio, and meet the needs of seismic exploration.
[0045] The method for multi-area fusion static correction of the present invention fuses the data of multiple single-area blocks and uniformly calculates the tomographic static correction amount. First, it can improve the accuracy of tomographic static correction at the boundary when processing single-block seismic data. Second, when processing multiple blocks, it can solve the time difference problem caused by the difference in tomographic static correction amount in the overlapping area of different blocks, and improve the signal-to-noise ratio of seismic data. The present invention can better solve the static correction problem, provide more accurate seismic data, lay a foundation for oil and gas seismic exploration, reduce the risk of exploration failure, and save exploration costs. The method has a good prospect for promotion and application, and is particularly suitable for complex surface exploration.
Claims
1. A fusion tomography static correction processing method for multiple working areas, characterized in that: The steps include: 1) Obtain the first arrival time file of each single work area for calibration, merge the calibrated first arrival time files to obtain a fused first arrival time file; the first arrival time file includes the geodetic coordinates and stake numbers of the shot points and the detection points in each single work area, the first arrival time, and the corresponding relationship between the shot points and the detection points; 2) converting the geodetic coordinates of each shot point and the geodetic coordinates of the receiver point in the fusion first arrival time file into the coordinate system of the fusion work area, and then performing fusion tomography inversion to obtain the velocity model of the fusion work area; the fusion work area is composed of each single block work area; 3) Obtain the velocity distribution range of the low-speed reduction zone and high-speed layer in the reference work area, divide the velocity model of the fusion work area, and obtain the high-speed top interface; 4) Calculate the detection point static correction and shot point static correction of the fusion work area based on the high-speed top interface.
2. The fusion tomography static correction processing method for multiple working areas according to claim 1 is characterized in that: In step 1), the first arrival time file of the corresponding work area is calibrated using the preset work area number.
3. The fusion tomography static correction processing method for multiple working areas according to claim 1 is characterized in that: In step 2), before performing fused tomographic inversion, the outliers in the fused first arrival time file are corrected.
4. The fusion tomography static correction processing method for multiple working areas according to claim 3 is characterized in that: In step 2), the micro-logging data of each single work area in the fusion work area is also obtained, and the micro-logging data is added to perform well constraints when performing fusion tomography inversion.
5. The fusion tomography static correction processing method for multiple working areas according to claim 1 is characterized in that: In step 3), the high-speed top interface is smoothed using a set small scale.
6. The fusion tomography static correction processing method for multiple working areas according to claim 1 is characterized in that: In step 4), the static correction of the receiver point and the static correction of the shot point in the fusion work area are calculated by the following formula: T s =T g -t (2) Where: T g is the static correction value of the detection point; T s is the static correction of the shot point; h1 and v1 are the thickness and velocity of the low-speed zone respectively; h2 and v2 are the thickness and velocity of the speed-reducing zone respectively; h d is the datum elevation; h g is the elevation of the high-speed top interface; v s is the filling speed; t is the well depth time.