Method and device for spatial homing of horizontal well geosteering picture to 3D seismic

Abstract

The application discloses a horizontal well geosteering picture three-dimensional seismic space homing method and equipment, and belongs to the field of physical exploration. The application finally obtains three-dimensional seismic data volume after space homing of a geosteering picture through the following steps: collecting data, establishing a well track information base, obtaining digital information in the geosteering picture after digitizing the engineering drawing, obtaining the space coordinates of the geosteering picture by using the well track information base, three-dimensional seismic space homing of a target formation geosteering picture and the like. The application uses the well track as a bridge, and directly connects the two-dimensional geosteering result with the three-dimensional seismic, so that the geosteering picture reflects the real stratum, and the three-dimensional seismic data volume directly embodies the real stratum, the purpose of objectively evaluating the three-dimensional seismic data volume from the same observation angle, and effectively predicting the depth, the dip angle, the breakpoint position and the microstructure is achieved. The application is applied to shale gas horizontal well drilling, and is further applied to the explanation and analysis of the geological structure.

Description

Technical Field

[0001] The present invention belongs to the field of physical exploration and relates to a geophysical signal interpretation, specifically a method and equipment for three-dimensional seismic spatial positioning of horizontal well geosteering images. Background Art

[0002] Geosteering is a core technology for horizontal shale gas well drilling. However, conventional geosteering methods based solely on a single measurement-while-drilling parameter are no longer sufficient for large-scale commercial shale gas development. Currently, the target thickness of horizontal shale gas wells in the southern Sichuan Basin is thin, with platinum targets less than 10 meters thick in some areas, and microstructures are well-developed, making drilling extremely challenging. To promote the refined development and iteration of geophysical technology, a multidisciplinary approach, based on the integrated seismic, geological, and engineering approach, is required to effectively analyze and evaluate existing technological achievements, identify technological breakthroughs, and enhance the support provided by geophysical exploration technology in drilling projects.

[0003] Well steering and seismic prediction are two independent disciplines. Well steering presents a continuous 3D geological volume as a 2D profile. The completed geosteering profile contains depth and horizontal displacement information. Depth-domain 3D seismic, on the other hand, is a discrete 3D data volume with X, Y coordinates and depth information. Current 3D seismic observation systems use bins (e.g., 20m x 20m) and are discrete data volumes. Currently, the integration of well steering and seismic prediction primarily involves extracting a 2D seismic profile along the well trajectory from the 3D seismic data volume. This profile is then aligned with the 2D drilling steering image using either a designed entry point (point A) and exit point (point B) or actual entry point (point A) and exit point (point B). The two profiles are then visually compared to analyze and evaluate the seismic prediction results. These results are qualitative, and their accuracy and reliability need to be improved. Existing techniques primarily overlay 2D images from the 3D seismic data volume with 2D photos from the geosteering image, failing to translate the actual stratigraphic formations reflected in the geosteering image into the 3D seismic data volume.

[0004] Because drilling guidance and seismic prediction have different observation angles and methods, there are disciplinary barriers when intersecting the two. It is difficult to directly place the geological guidance images obtained by drilling guidance and the three-dimensional seismic volume obtained by seismic prediction on the same platform for comparative analysis. The specific reasons are: (1) The three-dimensional seismic volume is a three-dimensional discrete data volume with information such as X, Y coordinates and depth; while the geological guidance image only contains altitude depth and horizontal displacement information obtained based on the well trajectory algorithm, and does not have the X, Y information of the three-dimensional seismic volume. (2) The geological guidance image of the completed drilling is a three-dimensional continuous geological body presented in the form of a two-dimensional profile, with horizontal displacement and altitude depth information; while the three-dimensional seismic data has surface element characteristics and is a discrete data volume, and the discreteness of the geological guidance image and the three-dimensional data volume is often mismatched. Therefore, if the geological guidance image of the completed drilling is to reflect the real strata in the three-dimensional seismic volume, it is necessary to overcome the above two difficulties. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a method for intuitively linking the results of two-dimensional geosteering with three-dimensional seismic data, so as to realize the reflection of the actual strata reflected in the geosteering images into the three-dimensional seismic volume, and objectively evaluate the accuracy of the current three-dimensional seismic data volume in terms of depth, dip, breakpoint location and micro-structure prediction from the same observation angle.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is:

[0007] A method for three-dimensional seismic spatial positioning of horizontal well geosteering images, the method comprising the following steps performed in sequence:

[0008] S1. Data Collection

[0009] Collect data to obtain 3D seismic data in the depth domain of the target formation, horizontal well drilling data, and geosteering images of completed horizontal wells;

[0010] S2. Establishing a well trajectory information database

[0011] Based on the horizontal well drilling data, the X, Y coordinate information and horizontal displacement are calculated by the minimum curvature method, and the well trajectory is interpolated to establish a well trajectory information database;

[0012] S3. Digital engineering drawings, obtaining digital information from geosteering images

[0013] Define the coordinate system of the drilling steering image. After digitizing the engineering drawing, pick up the completed horizontal well geosteering image and output the altitude depth and horizontal displacement data of the target formation in the coordinate system at a specific sampling interval.

[0014] S4. Use the well trajectory information database to obtain the spatial coordinates of the geosteering image

[0015] Using the horizontal displacement data of the target formation as a bridge, search the well trajectory information library for the X coordinate and Y coordinate corresponding to the same horizontal displacement, add the altitude depth information corresponding to the same horizontal displacement in step S3, and combine them into spatial coordinates;

[0016] S5. 3D seismic spatial positioning of target stratum geosteering images

[0017] The X and Y coordinate information in the spatial coordinates are projected onto the seismic network for matching using the minimum distance method;

[0018] The altitude depth information in the spatial coordinates is input into a depth domain three-dimensional seismic data volume to complete the three-dimensional seismic spatial positioning of the geosteering image of the target stratum and obtain a three-dimensional seismic multi-information data volume including the depth of the target stratum.

[0019] Preferably, in step S1, the horizontal well drilling data includes wellhead coordinates, core patching elevation and well trajectory data.

[0020] Preferably, in step S2, the horizontal well drilling data includes data such as deflection depth, well inclination angle, well inclination azimuth, X coordinate, Y coordinate and horizontal displacement.

[0021] Preferably, in step S3, in the drilling guidance image coordinate system, the abscissa is the horizontal displacement and the ordinate is the altitude depth;

[0022] The interval distance of the specific sampling interval matches the size of the seismic bin in the depth domain three-dimensional seismic data volume.

[0023] Preferably, in step S5,

[0024] The projection onto the seismic network based on the minimum distance method includes matching the obtained X and Y coordinates with the seismic network coordinates, searching for the inline and crossline positions of the seismic network closest to the coordinates, and converting the coordinate positions into network positions.

[0025] Preferably, step S5 may be followed by step S6 of three-dimensional seismic positioning of the true elevations of each sub-layer in the adjacent strata of the target stratum, specifically comprising:

[0026] S61. Using the horizontal well geosteering map, obtain the thickness difference between the bottom boundary of the target formation and the bottom boundary of the target formation in the internal sub-layer adjacent to the target formation;

[0027] S62. Based on the altitude depth information in the three-dimensional seismic multi-information data volume containing the depth of the target stratum obtained in step S5, the thickness difference obtained in step S61 is used to calculate the altitude depth of each small layer in the stratum adjacent to the target stratum and then display it in the three-dimensional seismic data volume to obtain the three-dimensional seismic spatial position of each small layer in the stratum adjacent to the target stratum.

[0028] The present invention also provides a computer device, which includes a memory, a processor, and a computer program stored in the memory and runnable on the processor. When the processor executes the computer program, the method for three-dimensional seismic spatial positioning of horizontal well geological guidance images is implemented.

[0029] The present invention also provides a computer-readable storage medium storing a computer program for executing the above-mentioned method for three-dimensional seismic spatial positioning of horizontal well geosteering images.

[0030] Due to the adoption of the above technical solution, the present invention has the following technical advancements compared with the prior art:

[0031] ① The present invention provides a method for 3D seismic spatial localization of horizontal well geosteering images. This method uses well trajectories as a bridge to intuitively link 2D geosteering results with 3D seismic data. This method objectively evaluates the current 3D seismic data volume for effective prediction of depth, dip, breakpoint location, and microstructure from the same observation angle. This method can also evaluate seismic depth data obtained by different migration processing methods, facilitating the iteration of high-precision geophysical exploration technology.

[0032] ② Unlike conventional geosteering images, which combine 2D sections with 2D images, this invention proposes, for the first time, to assign X and Y spatial information to geosteering images, thus upgrading them from 2D to 3D. By doing this 3D-to-3D mapping, the actual drilled geological horizons are accurately mapped to the seismic data space, facilitating further interpretation and analysis of geological structures.

[0033] ③ Step S2 in the present invention is a more critical step in this method. This step is based on the collected well inclination data such as inclination depth, well inclination angle, well inclination azimuth, etc., and uses the minimum curvature method to calculate the X and Y coordinates. Then, combined with the horizontal displacement, closing orientation and other information, the well trajectory is interpolated to establish a well trajectory information library. The purpose of this step is to provide a method for obtaining X and Y coordinate information in the well trajectory data; secondly, to interpolate the discrete points in the well trajectory into a continuous, smooth curve, which is conducive to laying the foundation for the subsequent acquisition of X and Y coordinate information in the geological guidance image that matches the discreteness of the three-dimensional seismic data body; the purpose of steps S3~S4 is to assign spatial coordinates to the target stratum in the geological guidance map, obtain the horizontal displacement and altitude depth of the target stratum through the digitized engineering map, and use the horizontal displacement to search for the corresponding X and Y coordinates in the well trajectory information library of step S2, so that the target stratum in the geological guidance map obtains X, Y coordinates and altitude depth information. This is the core step in this method;

[0034] ④ In step S5 of the present invention, the spatial coordinate information is projected onto the 3D seismic network. The X, Y, and altitude depth spatial coordinates obtained in step S4 are converted into the inline and crossline positions of the seismic network by the minimum distance principle, and the inline, crossline, and altitude depth data are input into the 3D seismic network.

[0035] ⑤ The 3D seismic data volume obtained by the present invention after spatial positioning of the geosteering image of the target stratum can be further used to realize the 3D seismic positioning of the true elevation of each internal sub-layer in the adjacent strata of the target stratum based on the thickness difference between the bottom boundary of the internal sub-layer and the bottom boundary of the target stratum, thus laying the foundation for the interpretation and analysis of the overall geological structure;

[0036] ⑥ The present invention also provides electronic equipment and storage media for executing the method for three-dimensional seismic spatial positioning of horizontal well geological steering images, with complete software and hardware supporting facilities, which facilitates the promotion and use of the testing method.

[0037] The present invention is applied to shale gas horizontal well drilling, especially in exploration areas with thin target thickness or micro-structure development where drilling is difficult, and is further applied to the interpretation and analysis of geological structures. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments.

[0039] Figure 1 This is a flow chart of the method for 3D seismic spatial positioning of horizontal well geosteering images in Example 1 of the present invention;

[0040] Figure 2This is a three-dimensional seismic spatial homing effect diagram of the geosteering image of the Lu 203HX-A well in Example 1 of the present invention;

[0041] Figure 3 This is a comparison chart of the prediction effects of seismic depth data obtained by different processing methods for the bottom boundary of the Wufeng Formation in Well Lu 203HX-A in Example 1 of the present invention. DETAILED DESCRIPTION

[0042] The present invention will be further described in detail below by means of specific embodiments in conjunction with the accompanying drawings. It should be understood that the embodiments described are preferred examples of the present invention and are only used to explain the present invention and are not intended to limit the present invention.

[0043] Example 1 A method for 3D seismic spatial positioning of horizontal well geosteering images

[0044] Due to the thin thickness of the target body for drilling shale gas horizontal wells in southern Sichuan, the thickness of the platinum target body in some areas is less than 10 meters, and the micro-structure is well developed, the drilling difficulty is very high. This embodiment takes the bottom boundary stratum of the Wufeng Formation in the southern Sichuan Basin as the target stratum as an example, and provides a method for 3D seismic spatial positioning of horizontal well geosteering images. The flow chart is as follows: Figure 1 As shown, the method includes the following steps performed in sequence:

[0045] S1. Data Collection

[0046] Collect data to obtain deep-domain 3D seismic data related to the base of the Wufeng Formation, horizontal well drilling data, and geosteering images of completed horizontal wells;

[0047] The horizontal well drilling data includes wellhead coordinates, core patching elevation and well trajectory data;

[0048] S2. Establishing a well trajectory information database

[0049] Based on the parameters such as the inclination depth, inclination angle, and inclination azimuth in the well trajectory data, the X, Y coordinates and horizontal displacement at a certain inclination depth are calculated using the minimum curvature method. Then, combined with the closed azimuth, the well trajectory is interpolated to establish a well trajectory information database.

[0050] S3. Digital engineering drawings, obtaining digital information from geosteering images

[0051] S31 defines a drilling steering image coordinate system, wherein the coordinate system uses horizontal displacement as the abscissa and elevation depth as the ordinate to digitize the geological steering image;

[0052] S32. Manually pick the bottom boundary of the Wufeng Formation on the digitized geosteering image and output the digitized information including the altitude depth and horizontal displacement data at a sampling interval of 20 meters in the above coordinate system;

[0053] The reason for choosing 20 meters as the sampling interval is that in the seismic observation system of the depth domain three-dimensional seismic data volume, the bin size is 20 meters;

[0054] S4. Obtain spatial coordinates using the well trajectory database

[0055] Using the horizontal displacement data of the bottom boundary of the Wufeng Formation obtained in step S32 as a bridge, search the well trajectory information library obtained in step S2 for the X-coordinate and Y-coordinate information corresponding to the same horizontal displacement, add the altitude depth information corresponding to the same horizontal displacement in step S3, and combine them into spatial coordinates;

[0056] S5. 3D seismic spatial positioning of target stratum geosteering images

[0057] The spatial coordinates are projected onto the seismic network using the minimum distance method for matching, the obtained X and Y coordinates are matched with the seismic network coordinates, the inline and crossline positions of the seismic network closest to the coordinates are searched, and the coordinate positions are converted into network positions;

[0058] The altitude depth information in the spatial coordinates is further input into the depth domain three-dimensional seismic data volume to complete the three-dimensional seismic spatial positioning of the geological guidance image of the bottom boundary stratum of the Wufeng Formation, and obtain a three-dimensional seismic multi-information data volume containing the depth information of the bottom boundary stratum of the Wufeng Formation.

[0059] The X and Y coordinate information in the spatial coordinates obtained in step S4 is projected onto the seismic network for matching based on the minimum distance method. The obtained X and Y coordinates are matched with the seismic network coordinates, and the inline and crossline positions of the seismic network closest to the coordinates are searched, and the coordinate positions are converted into the network positions.

[0060] According to the position of the survey network, the altitude depth information in the spatial coordinates is further input into the three-dimensional seismic data volume to complete the three-dimensional seismic spatial repositioning of the geological steering image of the bottom boundary of the Wufeng Formation, and obtain the three-dimensional seismic data volume after the spatial repositioning of the geological steering image of the bottom boundary of the Wufeng Formation.

[0061] S6. 3D seismic relocation of the true elevation of the internal sub-layers in the adjacent layers of the target layer

[0062] S61. Using the horizontal well geosteering map, obtain the thickness difference between the bottom boundary of each sub-layer within Long-1-1 of the Longmaxi Formation, which is adjacent to and above the bottom boundary of the Wufeng Formation, and the bottom boundary of the Wufeng Formation;

[0063] S62. Based on the altitude depth of the 3D seismic multi-information data volume containing the depth information of the bottom boundary of the Wufeng Formation obtained in step S5, the thickness difference obtained in step S61 is used to calculate the altitude depth of each small layer inside the Longmaxi Formation Longyi 1 and then display it in the 3D seismic data volume, and obtain the 3D seismic spatial relocation of each small layer inside the target Longmaxi Formation Longyi 1. Among them, the 3D seismic spatial relocation effect diagram of the geosteering image of the Lu 203HX-A well is as follows: Figure 2 shown.

[0064] Depend on Figure 2 As can be seen, the geosteering image is directly displayed in the 3D seismic data. The true positions of the Wufeng Formation, sub-layer 1, sub-layer 2, sub-layer 3, and sub-layer 4 are intuitively and accurately displayed on the seismic events. The image also shows that the seismic prediction accuracy of the horizontal well's target depth is high. The predicted stratigraphic dip in the first half of the well is more consistent with the actual stratigraphic dip than in the second half. The micro-tectonic seismic response in the middle is relatively weak, while the tail of the well accurately depicts the fault location. This image intuitively links the results of 2D geosteering with 3D seismic data, objectively evaluating the accuracy of current 3D seismic predictions of depth, dip, fault location, and micro-tectonic structure from the same observational perspective.

[0065] Based on the three-dimensional seismic spatial repositioning of the geosteering image of the Lu 203HX-A well obtained by this invention, it can be further applied to evaluate the seismic depth data obtained by different migration processing methods. For example, the degree of consistency between the predicted depth data obtained by different processing methods such as time-depth conversion, VTI anisotropic migration, and TTI anisotropic migration and the actual formation can be compared, so as to more intuitively select the migration processing method suitable for the local formation. Figure 3 This is a comparison chart of the prediction effects of seismic depth data obtained by different processing methods for the bottom boundary strata of the Wufeng Formation in Well Lu 203HX-A.

[0066] The method for 3D seismic spatial localization of horizontal well geosteering images provided by this invention has been successfully applied in 3D seismic tracking of shale gas while drilling in the Sichuan Basin. Currently, 3D seismic spatial localization of geosteering images of more than 150 shale gas horizontal wells has been completed in the southern Sichuan shale gas block, achieving excellent results.

[0067] Example 2: A computer device

[0068] This embodiment provides a computer device, which includes: a memory, a processor, and a computer program stored in the memory and executable on the processor, to implement the above-mentioned method for three-dimensional seismic spatial positioning of horizontal well geosteering images.

[0069] The above-mentioned memory is used to store non-transitory computer-readable instructions. Specifically, the memory may include one or more computer program products, which may include various forms of computer-readable storage media, such as volatile memory and / or non-volatile memory. The volatile memory may include, for example, random access memory (RAM) and / or cache memory. The non-volatile memory may include, for example, read-only memory (ROM), a hard disk, flash memory, etc.

[0070] The processor may be a central processing unit (CPU) or other processing unit having data processing capability and / or instruction execution capability, and may control other components in the electronic device to perform desired functions. The processor is configured to execute the computer-readable instructions stored in the memory.

[0071] Those skilled in the art should understand that in order to solve the technical problem of how to obtain a good user experience, this embodiment may also include well-known structures such as a communication bus and an interface, and these well-known structures should also be included in the scope of protection of this disclosure.

[0072] Example 3 A computer-readable storage medium

[0073] This embodiment provides a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, the method for three-dimensional seismic spatial positioning of horizontal well geosteering images is implemented.

[0074] The computer-readable storage medium stores non-transitory computer-readable instructions, which, when executed by a processor, execute all or part of the steps of the aforementioned methods.

[0075] The above-mentioned computer-readable storage media include, but are not limited to, optical storage media (e.g., CD-ROMs and DVDs), magneto-optical storage media (e.g., MOs), magnetic storage media (e.g., magnetic tapes or mobile hard disks), media with built-in rewritable non-volatile memory (e.g., memory cards), and media with built-in ROM (e.g., ROM cartridges).

[0076] The above description is merely an optional embodiment of the present disclosure and is not intended to limit the present disclosure. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present disclosure shall be included in the scope of protection of the present disclosure.

Claims

1. A method for three-dimensional seismic spatial positioning of horizontal well geosteering images, characterized in that: The method comprises the following steps performed in sequence: S1. Data Collection Collect data to obtain 3D seismic data in the depth domain of the target formation, horizontal well drilling data, and geosteering images of completed horizontal wells; S2. Establishing a well trajectory information database Based on the horizontal well drilling data, the X, Y coordinate information and horizontal displacement are calculated by the minimum curvature method, and the well trajectory is interpolated to establish a well trajectory information database; S3. Digital engineering drawings, obtaining digital information from geosteering images Define the coordinate system of the drilling steering image, digitize the engineering drawing, pick up the completed horizontal well geosteering image, and output the altitude depth and horizontal displacement data of the target formation at a specific sampling interval; S4. Use the well trajectory information database to obtain the spatial coordinates of the geosteering image Using the horizontal displacement data of the target formation as a bridge, search the X coordinate and Y coordinate corresponding to the same horizontal displacement in the well trajectory information library, add the altitude depth information corresponding to the same horizontal displacement in step S3, and combine them into spatial coordinates; S5. 3D seismic spatial positioning of target stratum geosteering images The X and Y coordinate information in the spatial coordinates are projected onto the seismic network for matching using the minimum distance method; Inputting the altitude depth information in the spatial coordinates into the depth domain 3D seismic data volume, completing the 3D seismic spatial positioning of the geosteering image of the target stratum, and obtaining a 3D seismic multi-information data volume including the depth of the target stratum; S6. 3D seismic relocation of the true elevation of each sub-layer within the adjacent strata of the target stratum Using the horizontal well geosteering map, the thickness difference between the bottom boundary of the internal sub-layer in the adjacent strata of the target stratum and the bottom boundary of the target stratum is obtained; Based on the three-dimensional seismic multi-information data volume containing the depth of the target stratum, the thickness difference is used to calculate the altitude depth of each small layer in the stratum adjacent to the target stratum and then display it in the three-dimensional seismic data volume to obtain the three-dimensional seismic spatial position of each small layer in the stratum adjacent to the target stratum.

2. The method for three-dimensional seismic spatial positioning of horizontal well geosteering images according to claim 1, characterized in that: In step S1, the horizontal well drilling data includes wellhead coordinates, core patching elevation and well trajectory data.

3. The method for three-dimensional seismic spatial positioning of horizontal well geosteering images according to claim 1, characterized in that: In step S2, the horizontal well drilling data includes data including deflection depth, well inclination angle, well inclination azimuth, X coordinate, Y coordinate and horizontal displacement.

4. The method for 3D seismic spatial positioning of horizontal well geosteering images according to claim 1, characterized in that: In step S3, in the coordinate system of the drilling guidance image, the horizontal coordinate is the horizontal displacement and the vertical coordinate is the altitude depth; The interval distance in the specific sampling interval matches the size of the seismic bin in the depth domain three-dimensional seismic data volume.

5. The method for three-dimensional seismic spatial positioning of horizontal well geosteering images according to any one of claims 1 to 4, characterized in that: In step S5, The projection onto the seismic network based on the minimum distance method includes matching the obtained X coordinates and Y coordinates with the seismic network coordinates, searching for the inline and crossline positions of the seismic network with appropriate distances from the coordinates, and converting the coordinate positions into network positions.

6. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the computer program, the method for three-dimensional seismic spatial positioning of horizontal well geosteering images according to any one of claims 1 to 5 is implemented.

7. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a computer program for executing the method for three-dimensional seismic spatial positioning of horizontal well geosteering images according to any one of claims 1 to 5.

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