Optimal method of stacking offset for sandstone body OVT domain zoned gather
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- CHINA PETROLEUM & CHEMICAL CORP
- Filing Date
- 2022-03-23
- Publication Date
- 2026-06-05
Smart Images
Figure CN116840920B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of exploration geophysics, and in particular to a method for optimizing the overlay offset of OVT domain regional gathers in conglomerate bodies. Background Technology
[0002] The steep slopes of several secondary depressions in the Jiyang Depression contain numerous sandstone and conglomerate fans. The depositional orientation and thickness of these fans vary considerably, and even within the same depression, the developmental characteristics of sandstone and conglomerate bodies differ significantly between different areas. Conventional seismic data do not account for these differences. However, OVT (Outer Threatened Variable) seismic data offers advantages such as high density, wide azimuth, and large offset, while also containing rich azimuth and offset information. Interpreters, through geological studies, specifically analyze OVT data based on different depositional orientations and stratigraphic dips in different regions. They select gathers from the OVT domain that best reflect the geological bodies under study for optimized overlay. The overlaid seismic data is then used for detailed studies of the geological bodies under investigation, aiding in well placement. Offset is one of the most crucial parameters in the optimized overlay of regional gathers; therefore, optimizing the offset is a prerequisite for interpreters to conduct optimized overlay of regional gathers within the OVT domain.
[0003] Chinese patent application CN202010529547.6 discloses a method and system for converting OVT domain data into azimuth domain imaging gathers. The method involves: first, calculating the Dix layer velocity and using it to set the initial layer velocity in the depth domain space; then, using an optimization objective function to determine the optimized layer velocity in the depth domain space; calculating the maximum reflection angle based on the optimized layer velocity in the depth domain space, and determining the reflection angle range; dividing the region into azimuth domain grids based on the azimuth and reflection angle ranges; and finally, calculating the reflection angle corresponding to each azimuth angle based on the optimized layer velocity in the depth domain space and the pre-stack time offset root mean square velocity in the OVT domain imaging gather data, thus obtaining the azimuth domain imaging gather. This invention, by solving an objective function, achieves the conversion of OVT domain data in laterally variable speed media into azimuth domain imaging gathers to improve the accuracy of AVA / AVAZ inversion.
[0004] Chinese patent application CN201610946011.8 discloses a pre-stack time migration method and apparatus. The method includes: mapping the seismic data to be migrated to a five-dimensional coordinate space, wherein the dimensions of the five-dimensional coordinate space include: CMP line number, CMP, recording time, shot-receiver distance, and azimuth angle; decomposing the seismic data mapped to the five-dimensional coordinate space along the shot-receiver distance and azimuth angle dimensions to obtain M OVT slices; dividing the M OVT slices into N OVT domain imaging tasks; and allocating the N OVT domain imaging tasks to multiple computing node groups for migration imaging. Within each computing node group, tasks are allocated to each computing node according to its processing capacity, and within each computing node, the CPU and GPU request tasks according to their respective processing capabilities. This invention solves the problem of long computation time in existing pre-stack migration imaging, achieving a simple and efficient technical effect for pre-stack time migration.
[0005] Chinese patent application CN201810256518.X discloses a method and apparatus for pre-stack time migration data processing. The method includes: obtaining OVT domain seismic data based on acquired wide-azimuth seismic data; performing static correction processing on the OVT domain seismic data to obtain statically corrected data; performing velocity analysis on the statically corrected data to obtain a root-mean-square velocity field; adding OVT information to the statically corrected data; performing regularization processing on the statically corrected data with added OVT information to obtain OVT set seismic data; and performing pre-stack time migration processing based on the OVT set seismic data and the root-mean-square velocity field. Utilizing the embodiments in this application improves the processing efficiency of pre-stack time migration and saves time in pre-stack time migration data processing.
[0006] The existing technologies described above are significantly different from the present invention and have failed to solve the technical problem we want to address. Therefore, we have invented a new method for optimizing the superimposed offset distance of the OVT domain partition gather in sandstone and conglomerate bodies. Summary of the Invention
[0007] The purpose of this invention is to provide a method for optimizing the offset of OVT domain gather data in conglomerate bodies. This method optimizes the offset of OVT domain gather data, and the optimized gather data superimposed on this basis can describe the favorable reservoir development zone of the conglomerate body.
[0008] The objective of this invention can be achieved through the following technical measures: a method for optimizing the overlay offset of OVT domain regional gathers in conglomerate bodies, which includes:
[0009] Step 1: Determine the burial depth H of the target layer fan body and the planar distribution map of the fan body in the study area;
[0010] Step 2: Optimize the optimal formula A for the time-depth relationship function of actual drilling reconstruction within the study area;
[0011] Step 3, calculate the tilt angle α of the fan body;
[0012] Step 4: Determine the maximum effective offset l2 of the straight section of the target layer reflection in the study area;
[0013] Step 5: Calculate the minimum effective offset distance l1 of the target layer sector in the study area;
[0014] Step 6: Combining steps 4 and 5, we obtain the optimal gather stacking offset range l for the target layer fan body in the study area.
[0015] The objective of this invention can also be achieved through the following technical measures:
[0016] In step 1, a comprehensive geological study and detailed structural interpretation of the target layer fan body are carried out to clarify the burial depth H of the target layer fan body and the planar distribution map of the fan body in the study area.
[0017] In step 1, the comprehensive logging, well logging, and drilling data are used to analyze and study the target layer, obtain the underground burial depth H of the target layer, use post-stack three-dimensional time-migrated seismic data to perform well-seismic joint calibration, carry out fine seismic structural interpretation of the target layer fan body, and obtain the time domain planar distribution map of the target layer fan body.
[0018] In step 2, the synthetic records of multiple representative actual drilling wells evenly distributed in the study area are reasonably selected and fitted with mathematical functions to obtain the time-depth relationship function formula A applicable to the study area.
[0019] In step 3, the time-domain planar distribution map of the sector is converted into a depth-domain planar distribution map using the time-depth relationship function formula A from step 2, and the tilt angle α of the sector is calculated.
[0020] In step 3, the time-depth relationship function of the study area reconstructed in step 2 is substituted as a constraint condition to convert the time domain planar distribution map of the fan into a depth domain planar distribution map. Based on the depth difference, i.e., the height h, of the depth domain planar distribution map of the fan and the horizontal distance s, the tilt angle α of the fan is calculated as arctan(h / s).
[0021] In step 4, pre-stack gather data analysis in the OVT domain is carried out, and the maximum effective offset l2 of the straight reflection segment of the target layer in the study area is determined based on the seismic reflection characteristics of the pre-stack gather of the target layer.
[0022] In step 4, the time-domain interpretation results of the target layer are first mapped to the pre-stack gather data in the OVT domain, and the maximum effective offset l2 of the target layer in the study area is determined based on the straight seismic reflection section of the target layer on the gather profile.
[0023] In step 5, the minimum effective offset distance l1 of the target layer fan body in the study area is calculated using the fan body depth H obtained in step 1 and the fan body tilt angle α obtained in step 3.
[0024] In step 5, the minimum effective offset distance l1 of the target layer fan in the study area is calculated using the fan depth H obtained in step 1 and the fan tilt angle α obtained in step 3 according to the formula l=H*tanα.
[0025] In step 6, combining steps 4 and 5, the optimal offset range l = (l1, l2) for stacking the target layer fan-shaped partition gathers in the study area is obtained.
[0026] The present invention provides a method for optimizing the offset of pre-stack gathers in the OVT domain of sandstone and conglomerate bodies. This method optimizes the offset (shot-receiver distance) of pre-stack gather data in the OVT domain. Based on this optimization, the resulting optimized gather-stacked seismic data can better describe favorable reservoir development zones within the sandstone and conglomerate body. This method can relatively accurately calculate the optimal offset range for stacking optimized gathers in the OVT domain of the target layer, and the resulting seismic data volume better reflects the distribution range of sandstone and conglomerate fans and effective reservoir development zones. Attached Figure Description
[0027] To make the above and other objects, features and advantages of the present invention more apparent and understandable, a detailed description is provided below in conjunction with the accompanying drawings.
[0028] Figure 1 A flowchart illustrating a specific embodiment of the method for optimizing the overlay offset of gathers in the OVT domain of a conglomerate mass according to the present invention;
[0029] Figure 2 This is a comprehensive logging diagram of a specific drilling well in Shengli, as described in a specific embodiment of the present invention.
[0030] Figure 3 This is a longitudinal seismic profile of a certain work area in Shengli No. 1, according to a specific embodiment of the present invention.
[0031] Figure 4 This is a time-domain planar distribution diagram of a sandstone fan in a specific embodiment of the present invention;
[0032] Figure 5 This is a time-depth relationship diagram of the Shengli No. 1 work area in a specific embodiment of the present invention;
[0033] Figure 6 This is a planar distribution diagram of the depth domain of a sandstone and conglomerate fan in a specific embodiment of the present invention;
[0034] Figure 7This is a cross-sectional view of a certain track collection in a specific embodiment of the present invention;
[0035] Figure 8 This is a schematic diagram of the minimum offset calculation profile of a certain work area in Shengli, according to a specific embodiment of the present invention;
[0036] Figure 9 This is a cross-sectional view of the preferred range of offset distance of a certain work area in Shengli, according to a specific embodiment of the present invention. Detailed Implementation
[0037] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.
[0038] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments of the present invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, and / or combinations thereof.
[0039] The OVT domain zoning optimization method for sandstone and conglomerate bodies of this invention includes: Step 1, determining the burial depth H of the target layer fan body and the fan body planar distribution map in the study area; Step 2, rationally selecting the optimal time-depth relationship function formula A for reconstruction of actual drilled wells in the study area; Step 3, calculating the fan body dip angle α; Step 4, determining the maximum effective offset l2 of the straight reflection segment of the target layer in the study area; Step 5, calculating the minimum effective offset l1 of the target layer fan body in the study area; Step 6, combining Step 4 and Step 5 to obtain the optimal gather stacking offset range l of the target layer fan body in the study area. This OVT domain zoning optimization gather stacking offset optimization method for sandstone and conglomerate bodies can relatively accurately calculate the optimal offset range of the target layer OVT domain zoning optimization gather stacking, and the obtained seismic data volume can better reflect the distribution range of sandstone and conglomerate fans and the effective reservoir development area.
[0040] The following are several specific embodiments of the application of the present invention.
[0041] Example 1
[0042] In a specific embodiment 1 of the present invention, the method for optimizing the overlay offset of aggregate OVT domain partitioning in conglomerate mass includes the following steps:
[0043] Step 1: Conduct comprehensive geological research and detailed structural interpretation of the target layer fan body, and clarify the burial depth H of the target layer fan body and the planar distribution map of the fan body in the study area;
[0044] Step 2: Optimize the optimal formula A for the time-depth relationship function of actual well reconstruction within the study area;
[0045] Step 3: Use the time-depth relationship function formula A from Step 2 to convert the time-domain planar distribution map of the sector into a depth-domain planar distribution map, and calculate the sector tilt angle α;
[0046] Step 4: Conduct pre-stack gather data analysis in the OVT domain, and determine the maximum effective offset l2 of the straight reflection segment of the target layer in the study area based on the seismic reflection characteristics of the pre-stack gather of the target layer.
[0047] Step 5: Using the study area fan depth H obtained in Step 1 and the study area fan tilt angle α obtained in Step 3, calculate the minimum effective offset distance l1 of the target layer fan in the study area.
[0048] Step 6: Combining steps 4 and 5, we obtain the optimal gather stacking offset range l for the target layer fan body in the study area.
[0049] In step 6, combining steps 4 and 5, the optimal offset range l = (l1, l2) for stacking the target layer fan-shaped partition gathers in the study area is obtained.
[0050] Example 2
[0051] In a specific embodiment 2 of the present invention, the method for optimizing the overlay offset of aggregate OVT domain partitioning in conglomerate mass includes the following steps:
[0052] In step 1, the comprehensive logging, well logging, and drilling data are used to analyze and study the target layer, obtain the underground burial depth H of the target layer, use post-stack three-dimensional time-migrated seismic data to perform well-seismic joint calibration, carry out fine seismic structural interpretation of the target layer fan body, and obtain the time domain planar distribution map of the target layer fan body.
[0053] In step 2, the synthetic records of multiple representative actual drilling wells evenly distributed in the study area are reasonably selected and fitted with mathematical functions to obtain the time-depth relationship function formula A applicable to the study area.
[0054] In step 3, the time-depth relationship function of the study area reconstructed in step 2 is substituted as a constraint condition to convert the time domain planar distribution map of the fan into a depth domain planar distribution map. The fan tilt angle α is calculated based on the depth difference (i.e., height h) and horizontal distance s of the depth domain planar distribution map of the fan, where α = arctan(h / s).
[0055] In step 4, the time-domain interpretation results of the target layer are first mapped to the pre-stack gather data in the OVT domain, and the maximum effective offset l2 of the target layer in the study area is determined based on the straight seismic reflection section of the target layer on the gather profile.
[0056] In step 5, the minimum effective offset distance l1 of the target layer fan in the study area is calculated using the fan depth H obtained in step 1 and the fan tilt angle α obtained in step 3 according to the formula l=H*tanα.
[0057] In step 6, combining steps 4 and 5, the optimal offset range l = (l1, l2) for stacking the target layer fan-shaped partition gathers in the study area is obtained.
[0058] Example 3
[0059] In a specific embodiment 2 of the present invention, such as Figure 1 As shown, Figure 1 This is a flowchart of a method for optimizing the superposition offset of OVT domain partition gathers in sandstone and conglomerate bodies according to the present invention.
[0060] In step 101, the comprehensive logging, well logging, and drilling data are used to analyze and study the target layer to obtain the underground burial depth H of the target layer. Well-seismic joint calibration is performed using post-stack three-dimensional time-migrated seismic data to carry out fine seismic structural interpretation of the target layer fan and obtain the time domain planar distribution map of the target layer fan. Figure 2 The image shows a comprehensive logging chart of a certain well in Shengli, with the target formation buried at a depth H of approximately 2000m. Figure 3 This is a longitudinal profile of a seismic event in the Shengli No. 1 work area. Figure 4 This is a time-domain planar distribution map of a sandstone fan in a specific embodiment of the present invention. The process proceeds to step 102.
[0061] In step 102, the synthetic records of multiple representative actual drilling wells evenly distributed in the study area are reasonably selected and subjected to mathematical function fitting to obtain the time-depth relationship function formula A applicable to the study area. Figure 5 This is a time-depth relationship diagram for the Shengli No. 1 work area in a specific embodiment of the present invention. The process proceeds to step 103.
[0062] In step 103, the time-depth relationship function of the study area reconstructed in step 2 is substituted as a constraint condition to convert the time domain planar distribution map of the fan into a depth domain planar distribution map. The fan tilt angle α is calculated based on the depth difference (i.e., height h) and horizontal distance s of the depth domain planar distribution map of the fan, where α = arctan(h / s). Figure 6 This is a planar distribution map of the depth domain of a sandstone fan in a specific embodiment of the present invention, with the fan dip angle α (21°) in the study area. The process proceeds to step 104.
[0063] In step 104, the time-domain interpretation results of the target layer are first mapped to the pre-stack gather data in the OVT domain, and the maximum effective offset l2 of the target layer in the study area is determined based on the straight seismic reflection section of the target layer on the gather profile. Figure 7A section of a track in the Shengli No. 1 work area shows the maximum effective offset l2 (3000m) of the target layer in the study area. The process proceeds to step 105.
[0064] In step 105, the minimum effective offset distance l1 of the target layer fan in the study area is calculated using the fan depth H obtained in step 101 and the fan tilt angle α obtained in step 103 according to the formula l=H*tanα. Figure 8 This is a schematic diagram of the minimum offset calculation profile for a certain work area in Shengli. The minimum effective offset of the target layer fan body in the study area is l1 (600m). The process proceeds to step 106.
[0065] In step 106, combining steps 104 and 105, the optimal offset range l = (l1, l2) for stacking the target layer fan-shaped partition gathers in the study area is obtained. Figure 9 The preferred offset range profile for a certain work area of Shengli is (600, 3000).
[0066] This invention provides a method for optimizing the offset of pre-stack gathers in the OVT domain of conglomerate bodies. This method optimizes the offset of pre-stack gather data in the OVT domain, and the resulting optimized gather-stacked seismic data can better describe the favorable reservoir development zones of the conglomerate body. This method can relatively accurately calculate the optimal offset range for stacking optimized gathers in the OVT domain of the target layer, and the resulting seismic data volume can better reflect the distribution range of the conglomerate fan and the effective reservoir development zones.
[0067] 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 foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
[0068] Except for the technical features described in the specification, all other technologies are known to those skilled in the art.
Claims
1. A method for optimizing the stacking offset of OVT domain regional gathers in conglomerate mass sandstone, characterized in that, The optimal method for selecting the overlay offset of the OVT domain regional gathers in this conglomerate mass includes: Step 1: Determine the burial depth H of the target layer fan body and the planar distribution map of the fan body in the study area; Step 2: Optimize the optimal formula A for the time-depth relationship function of actual drilling reconstruction within the study area; Step 3, calculate the tilt angle α of the fan body; Step 4: Determine the maximum effective offset l2 of the straight section of the target layer reflection in the study area; Step 5: Calculate the minimum effective offset distance l1 of the target layer sector in the study area; Step 6: Combining steps 4 and 5, we obtain the optimal gather stacking offset range l for the target layer fan body in the study area; In step 4, pre-stack gather data analysis in the OVT domain is carried out, and the maximum effective offset l2 of the straight reflection segment of the target layer in the study area is determined based on the seismic reflection characteristics of the pre-stack gather of the target layer. In step 5, the minimum effective offset distance l1 of the target layer fan in the study area is calculated using the fan depth H obtained in step 1 and the fan tilt angle α obtained in step 3 according to the formula l = H*tanα.
2. The method for optimizing the superimposed offset distance of OVT domain regional gathers in sandstone and conglomerate bodies according to claim 1, characterized in that, In step 1, a comprehensive geological study and detailed structural interpretation of the target layer fan body are carried out to clarify the burial depth H of the target layer fan body and the planar distribution map of the fan body in the study area.
3. The method for optimizing the superimposed offset distance of OVT domain regional gathers in sandstone and conglomerate bodies according to claim 2, characterized in that, In step 1, the comprehensive logging, well logging, and drilling data are used to analyze and study the target layer, obtain the underground burial depth H of the target layer, use post-stack three-dimensional time-migrated seismic data to perform well-seismic joint calibration, carry out fine seismic structural interpretation of the target layer fan body, and obtain the time domain planar distribution map of the target layer fan body.
4. The method for optimizing the superimposed offset distance of OVT domain regional gathers in sandstone and conglomerate bodies according to claim 1, characterized in that, In step 2, the synthetic records of multiple representative actual drilling wells evenly distributed in the study area are reasonably selected and fitted with mathematical functions to obtain the time-depth relationship function formula A applicable to the study area.
5. The method for optimizing the superimposed offset distance of OVT domain regional gathers in sandstone and conglomerate bodies according to claim 1, characterized in that, In step 3, the time-domain planar distribution map of the sector is converted into a depth-domain planar distribution map using the time-depth relationship function formula A from step 2, and the tilt angle α of the sector is calculated.
6. The method for optimizing the superimposed offset distance of OVT domain regional gathers in sandstone and conglomerate bodies according to claim 5, characterized in that, In step 3, the time-depth relationship function of the study area reconstructed in step 2 is substituted as a constraint condition to convert the time domain planar distribution map of the fan into a depth domain planar distribution map. Based on the depth difference, i.e., the height h, of the depth domain planar distribution map of the fan and the horizontal distance s, the tilt angle α of the fan is calculated as arctan(h / s).
7. The method for optimizing the superimposed offset distance of OVT domain regional gathers in sandstone and conglomerate bodies according to claim 1, characterized in that, In step 4, the time-domain interpretation results of the target layer are first mapped to the pre-stack gather data in the OVT domain, and the maximum effective offset l2 of the target layer in the study area is determined based on the straight seismic reflection section of the target layer on the gather profile.
8. The method for optimizing the superimposed offset distance of OVT domain regional gathers in sandstone and conglomerate bodies according to claim 1, characterized in that, In step 6, combining steps 4 and 5, the optimal offset range l = (l1, l2) for stacking the target layer fan-shaped partition gathers in the study area is obtained.