An initial velocity modeling method based on drilling information and geologic horizon

Abstract

The application discloses an initial velocity modeling method based on drilling information and geologic horizon, which comprises the following steps: determining a spatial well velocity curve according to drilling information of a target work area; fusing geologic horizon information obtained through field reconnaissance and geologic horizon information obtained through a seismic profile to obtain fused geologic horizon information; extracting a structural continuity attribute from the fused geologic horizon information; and guiding structural constraint interpolation of the spatial well velocity curve by using the continuity attribute to obtain an initial velocity model which varies along a structural trend, wherein the initial velocity model is used for depth domain velocity modeling.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of oil and gas geophysical exploration engineering technology, and in particular to an initial velocity modeling method based on drilling information and geological strata. Background Technology

[0002] Depth domain processing of seismic data is widely recognized as the most accurate and advanced method in the industry, with depth domain velocity modeling and depth domain migration imaging being two crucial components. Over the past decade, seismic depth domain velocity modeling techniques have evolved from time-depth conversion, depth domain residual curvature analysis, and reflection wave grid tomography to full waveform inversion, gradually improving velocity modeling accuracy. However, the problem of mismatch between the final imaging results and actual drilling information still exists. In particular, the determination of the initial model in velocity modeling often determines the reliability of the entire velocity modeling result.

[0003] Both reflective wave grid tomography based on travel time theory and full-waveform inversion velocity modeling based on wave theory are iterative velocity modeling processing schemes. Reflective wave grid tomography first uses an initial velocity model for pre-stack depth migration to obtain migration gathers and profiles. Then, it extracts the remaining depth difference and reflection dip angle from the imaging gathers, establishes the tomographic equations, and solves the discrete large-scale sparse equation set using ray tracing and an iterative method to obtain the velocity correction. This updates the initial velocity model, and a new round of iterations is performed to obtain a high-precision velocity model. Full-waveform inversion, on the other hand, uses the initial model to perform forward and backward propagation calculations of the wave equations. After obtaining the update direction (gradient) of the entire velocity model space, it performs a reasonable step size estimation, finally obtaining the velocity model update amount and correcting the initial velocity model, then performing a new round of iterative calculations to obtain a high-precision velocity model. Although reflective wave grid tomography is less dependent on the initial velocity model, a more accurate initial velocity model that better reflects subsurface tectonic trends will undoubtedly accelerate the number of iterative modeling iterations, thereby reducing the time cost of seismic data processing. The full waveform requires a suitable initial model to ensure the accuracy and reliability of velocity modeling. If the initial model deviates too much from the real model, the full waveform inversion algorithm may completely fail. Summary of the Invention

[0004] To address the aforementioned technical problems, at least one embodiment of the present invention provides an initial velocity modeling method based on drilling information and geological strata, in order to solve the technical problem of inaccurate depth domain seismic velocity modeling in the presence of complex structures or geological anomalies on the surface and underground.

[0005] In some optional embodiments, the method includes the following steps:

[0006] Determine the space well velocity curve based on drilling information from the target work area;

[0007] The geological stratigraphic information obtained from field reconnaissance of the target work area is combined with the geological stratigraphic information obtained from seismic profiles to obtain the fused geological stratigraphic information.

[0008] Extract structural continuity attributes from the fused geological stratigraphic information;

[0009] The continuity property is used to guide the structural constraint interpolation of the space well velocity curve to obtain an initial velocity model that varies along the tectonic trend.

[0010] In some optional embodiments, determining the space well velocity curve based on drilling information of the target work area includes:

[0011] Outlier removal and low-pass filtering were performed on the logging data of the target work area to obtain a spatial well velocity curve that conforms to the frequency band of the seismic processing.

[0012] Based on the real coordinates of the well logging time series data and the grid coordinates of the target work area, the well logging discrete points are determined through coordinate mapping.

[0013] In some optional embodiments, the process of fusing the geological stratigraphic information obtained from field reconnaissance of the target work area with the geological stratigraphic information picked up from seismic profiles to obtain fused geological stratigraphic information includes:

[0014] Obtain geological profile image data of the target work area through field reconnaissance, and obtain the corresponding three-dimensional data volume of geological strata based on the geological profile image data;

[0015] The corresponding three-dimensional geological stratigraphic data volume is obtained by picking the marker layer from the depth domain seismic profile results.

[0016] The three-dimensional geological stratigraphic data obtained through field reconnaissance is weighted and fused with the three-dimensional geological stratigraphic data obtained through depth domain seismic profile results to obtain fused geological stratigraphic information.

[0017] In some optional embodiments, the weighted fusion of the three-dimensional geological stratigraphic data volume obtained through field reconnaissance and the three-dimensional geological stratigraphic data volume picked up through depth-domain seismic profiling results to obtain fused geological stratigraphic information includes:

[0018] After preserving the shallow portion of the three-dimensional geological stratigraphic data obtained through field reconnaissance, a weighted fusion of shallow, medium, and deep data is performed with the three-dimensional geological stratigraphic data obtained through depth-domain seismic profiles to obtain fused geological stratigraphic information.

[0019] In some optional embodiments, the extraction of structural continuity attributes from the fused geological stratigraphic information includes:

[0020] The fused geological stratigraphic information is used to perform boundary-preserving calculation of the three-dimensional spatial structure tensor, and the three-dimensional data volume of the geological stratigraphic continuity attribute of the target work area is extracted.

[0021] In some optional embodiments, the step of using the continuity property to guide the structural constraint interpolation of the space well velocity curve includes:

[0022] Based on the three-dimensional data volume of geological stratigraphic continuity attributes, regional interpolation and smoothing are performed on the scattered data of the spatial well velocity curve near the stratigraphic structure to obtain an initial velocity model volume that varies along the tectonic trend.

[0023] In some alternative embodiments, the method further includes: performing depth domain velocity modeling using the initial velocity model.

[0024] At least one embodiment of the present invention also provides an initial velocity modeling apparatus based on drilling information and geological strata, characterized in that it comprises:

[0025] The well logging data module is used to determine the spatial well velocity curve and well logging discrete sequence points based on the drilling information of the target work area;

[0026] The geological stratigraphy module is used to merge the geological stratigraphy information of the target work area obtained through field reconnaissance with the geological stratigraphy information picked up through seismic profiles to obtain fused geological stratigraphy information.

[0027] The attribute extraction module is used to extract structural continuity attributes from the fused geological stratigraphic information;

[0028] The constraint interpolation module is used to guide the spatial well velocity curve to perform structural constraint interpolation using the continuity attribute, so as to obtain an initial velocity model that varies along the structural trend. The initial velocity model is used for depth domain velocity modeling.

[0029] At least one embodiment of the present invention also provides an electronic device, characterized in that it comprises:

[0030] At least one processor; and,

[0031] A memory communicatively connected to the at least one processor; wherein,

[0032] The memory stores instructions that can be executed by the at least one processor to enable the at least one processor to perform the initial velocity modeling method based on drilling information and geological strata as described above.

[0033] At least one embodiment of the present invention also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the initial velocity modeling method based on drilling information and geological strata as described above.

[0034] At least one embodiment of the present invention also provides a computer program product, including a computer program that, when executed by a processor, implements the steps of the initial velocity modeling method based on drilling information and geological strata as described above.

[0035] Compared with the prior art, the initial velocity modeling method based on drilling information and geological strata provided by the embodiments of the present invention has the following beneficial effects:

[0036] This invention establishes a relatively accurate and reliable initial velocity model in the depth domain by constructing drilling information and geological stratum information for the work area. This provides accuracy assurance for subsequent stages of depth domain velocity modeling in seismic exploration and solves the problem of inaccurate depth domain seismic velocity modeling, especially when there are complex structures or geological anomalies on the surface and underground. Attached Figure Description

[0037] One or more embodiments are illustrated by way of example with reference to the accompanying drawings, and these illustrative descriptions do not constitute a limitation on the embodiments.

[0038] Figure 1 This is a flowchart illustrating the steps of the initial velocity modeling method based on drilling information and geological strata used in Embodiment 1 of the present invention.

[0039] Figure 2 This is a schematic diagram of the logging data used in Embodiment 2 of the present invention and a schematic diagram of the logging curve after preprocessing;

[0040] Figure 3 This is a schematic diagram of the shallow geological outcrop image data used in Embodiment 2 of the present invention;

[0041] Figure 4 This is a schematic diagram of the reflectance of deep geological strata used in Embodiment 2 of the present invention;

[0042] Figure 5 This is a schematic diagram of the spatial structural continuity attribute extracted in Embodiment 2 of the present invention;

[0043] Figure 6 This is a schematic diagram of the processing result obtained in Embodiment 2 of the present invention. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the various embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details are presented in the embodiments of the present invention to facilitate a better understanding of the invention. However, the technical solutions claimed in the present invention can be implemented even without these technical details and various variations and modifications based on the following embodiments. The division of the following embodiments is for ease of description and should not constitute any limitation on the specific implementation of the present invention. The various embodiments can be combined with and referenced by each other without contradiction.

[0045] As mentioned earlier, depth domain processing of seismic data requires an accurate velocity model as its foundation. Existing high-precision depth domain velocity modeling techniques all require a reasonable initial velocity model to improve the practicality and modeling accuracy of the technology. The initial velocity modeling method proposed in this invention first extracts relatively accurate well data information from seismic exploration, and performs appropriate preprocessing on the well logging data to obtain spatial well velocity curves. Based on geological profile data obtained from field reconnaissance, and combined with stratigraphic information picked from time-domain seismic profile results, a relatively accurate geological stratigraphic level is obtained. Then, structural continuity attributes are extracted from this geological stratigraphic information. Finally, this continuity attribute is used to guide structural constraint interpolation of the spatial well velocity curves, ultimately obtaining a reliable initial model for depth domain velocity modeling.

[0046] The implementation details of the above method are described in detail below through examples. The following content is only for the convenience of understanding the implementation details and is not necessary for implementing this solution.

[0047] Example 1:

[0048] like Figure 1 As shown in the figure, this embodiment provides an initial velocity modeling method based on drilling information and geological strata. The method mainly includes the following steps.

[0049] S1. Obtain several drilling data in the work area, perform outlier removal and low-pass filtering on the drilling data to obtain well velocity curve data within the seismic processing frequency band, and then map the coordinates to obtain discrete point data within the entire work area grid.

[0050] In specific implementation, step S1 acquires several drilling data points in the work area, performs outlier removal and low-pass filtering on the drilling data to obtain well velocity curve data within the seismic processing frequency band, and then maps the coordinates to obtain discrete point data within the entire work area grid. Based on the relevant parameters of the acquired logging data, the true depth of the logging data is corrected to the depth value relative to the seismic data processing reference surface, and then outliers are removed from the logging data according to its variance and standard deviation. Bandpass filtering is applied to the data after outlier removal to retain the low-frequency trend of the logging data curve. Based on the true coordinates of the actual logging time series data and the work area grid coordinates, discrete points of the logging data in the three-dimensional space of the work area are obtained.

[0051] S2: Acquire geological profile image data obtained from field reconnaissance in the work area. Convert this geological profile image data into a three-dimensional data volume covering the entire work area that can be accessed by electronic devices based on coordinate mapping. Obtain the initial depth domain result profile based on the previous time domain processing data, and then pick the marker layer stratigraphic data to obtain the three-dimensional data volume covering the entire work area.

[0052] In specific implementation, step S2 acquires geological profile image data obtained from field reconnaissance in the work area, and converts this geological profile image data into a three-dimensional data volume covering the entire work area that can be accessed by electronic devices according to coordinate mapping. Based on the preliminary time-domain processing data, an initial depth-domain result profile is obtained, and then marker layer stratigraphic data is extracted to acquire a three-dimensional data volume covering the entire work area. For the geological profile image data obtained from field reconnaissance, the geological outcrop structure profiles collected in the work area (generally in electronic image format) are converted from image format to binary seismic data format, and the data is interpolated and extended to convert it into a three-dimensional geological profile reflectance field applicable to the entire exploration area. Based on the initial depth-domain result profile, marker layer stratigraphic data is extracted, and this stratigraphic data is binarized to convert it into a three-dimensional stratigraphic profile reflectance field applicable to the entire exploration area.

[0053] S3, geological stratigraphic data fusion, selects the three-dimensional spatial data volume of geological stratigraphy obtained from field reconnaissance in S2, retains the shallow layer, and performs weighted fusion with the three-dimensional spatial data volume of geological stratigraphy picked from seismic profiles, which is then used for shallow, medium and deep layers.

[0054] In practical implementation, step S3, geological stratigraphic data fusion, involves selecting the shallow layers of the 3D spatial data volume of geological stratigraphy obtained from field reconnaissance in step S2 and performing a weighted fusion with the 3D spatial data volume of geological stratigraphy picked from seismic profiles, weighted by shallow, medium, and deep layers. The geological stratigraphic data obtained from field reconnaissance has relatively accurate geological structural characteristics in shallow layers, while the picked marker layers have more accurate structural characteristics in deeper layers. Therefore, the shallow layers of the 3D spatial data volume of geological stratigraphy obtained from field reconnaissance in step S2 are retained, and a weighted fusion is performed with the 3D spatial data volume of geological stratigraphy picked from seismic profiles, weighted by shallow, medium, and deep layers. The weighting varies from 0 to 1 in the transition zone. The transition zone is generally determined based on the conditions of the work area.

[0055] S4, for the fused stratigraphic data obtained in S3, performs boundary-preserving calculation of the three-dimensional spatial structure tensor on the data volume, and extracts the three-dimensional data volume of geological stratigraphic continuity attributes of the entire work area.

[0056] In practical implementation, step S4, based on the fused stratigraphic data obtained in S3, performs boundary-preserving calculation of the three-dimensional spatial structure tensor of the data volume, extracting the three-dimensional data volume of geological stratigraphic continuity attributes for the entire work area. The geological stratigraphic continuity attributes calculated by this invention are essentially the spatial structure tensor volume of the three-dimensional stratigraphic data. By obtaining the feature vectors of the local continuity structure, the changing trend of the spatial structure skeleton of the stratigraphic data is acquired.

[0057] S5, based on the scattered well data within the work area obtained in S1 and the formation continuous attribute data obtained in S4, performs structural constraint interpolation calculation, and performs regional interpolation and smoothing on the scattered data near the stratigraphic structure through continuous attributes to obtain the initial velocity model body that varies along the tectonic trend.

[0058] In specific implementation, step S5 performs structural constraint interpolation calculations based on the scattered well data within the work area obtained in S1 and the formation continuity attribute data obtained in S4. The scattered well data near the stratigraphic structure is interpolated and smoothed using the continuity attributes to obtain an initial velocity model volume that varies along the structural trend. Step S4 obtains the spatial structural skeleton variation trend of the stratigraphic data. Based on the constraints of this continuity attribute data, spatial interpolation and smoothing are performed on the discrete sequence point data from well logging to obtain an initial velocity model volume that varies along the structural trend.

[0059] S6 converts the velocity model data obtained from S5 into the standard SEGY format and outputs it to the disk for subsequent deep domain velocity modeling.

[0060] In practice, step S6 converts the velocity model data obtained in step S5 into the standard SEGY format and outputs it to the disk for subsequent depth domain velocity modeling.

[0061] Example 2

[0062] The technical solution of the present invention and its beneficial effects will be further illustrated below with a specific example.

[0063] In this embodiment, the implementation process of the initial velocity modeling method based on drilling information and geological strata provided by the present invention is as follows.

[0064] S1. Acquire several drilling data points in the work area. Perform outlier removal and low-pass filtering on the drilling data to obtain well velocity curve data within the seismic processing frequency band. Then, map the coordinates to obtain discrete point data within the entire work area grid. The original logging data and preprocessed well curve data are as follows: Figure 2 As shown.

[0065] S2, acquire geological profile image data obtained from field reconnaissance in the work area, such as Figure 3 As shown, the geological profile image data is converted into a three-dimensional data volume covering the entire work area, accessible to electronic devices, based on coordinate mapping. An initial depth-domain profile is obtained from previous time-domain processed data, and then marker layer stratigraphic data is extracted to acquire the three-dimensional data volume covering the entire work area, as shown below. Figure 4 As shown.

[0066] S3, geological stratigraphic data fusion, selects the three-dimensional spatial data volume of geological stratigraphy obtained from field reconnaissance in S2, retains the shallow layer, and performs weighted fusion with the three-dimensional spatial data volume of geological stratigraphy picked from seismic profiles, which is then used for shallow, medium and deep layers.

[0067] S4, based on the fused stratigraphic data obtained in S3, performs boundary-preserving calculations of the three-dimensional spatial structure tensor on this data volume, extracting the three-dimensional data volume of geological stratigraphic continuity attributes for the entire work area. For example... Figure 5 As shown.

[0068] S5, based on the scattered well data within the work area obtained in S1 and the formation continuous attribute data obtained in S4, performs structural constraint interpolation calculations. The scattered data near the stratigraphic structure are then regionally interpolated and smoothed using continuous attributes to obtain an initial velocity model volume that varies along the structural trend. For example... Figure 6 As shown.

[0069] S6 converts the velocity model data obtained from S5 into the standard SEGY format and outputs it to the disk for subsequent deep domain velocity modeling.

[0070] Example 3

[0071] Another embodiment of the present invention relates to an initial velocity modeling apparatus based on drilling information and geological strata, comprising:

[0072] The well logging data module is used to determine the spatial well velocity curve and well logging discrete sequence points based on the drilling information of the target work area;

[0073] The geological stratigraphy module is used to merge the geological stratigraphy information of the target work area obtained through field reconnaissance with the geological stratigraphy information picked up through seismic profiles to obtain fused geological stratigraphy information.

[0074] The attribute extraction module is used to extract structural continuity attributes from the fused geological stratigraphic information;

[0075] The constraint interpolation module is used to guide the spatial well velocity curve to perform structural constraint interpolation using the continuity attribute, so as to obtain an initial velocity model that varies along the structural trend. The initial velocity model is used for depth domain velocity modeling.

[0076] Example 4:

[0077] Another embodiment of the present invention relates to an electronic device, comprising: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to perform the initial velocity modeling method based on drilling information and geological strata in the above embodiments.

[0078] The memory and processor are connected via a bus, which can include any number of interconnecting buses and bridges, connecting various circuits of one or more processors and memories. The bus can also connect various other circuits, such as peripheral devices, voltage regulators, and power management circuits, which are well known in the art and will not be described further herein. The bus interface provides an interface between the bus and the transceiver. The transceiver can be a single element or multiple elements, such as multiple receivers and transmitters, providing a unit for communicating with various other devices over a transmission medium. Data processed by the processor is transmitted over the wireless medium via an antenna, which further receives data and transmits it to the processor.

[0079] The processor manages the bus and general processing, and also provides various functions, including timing, peripheral interfaces, voltage regulation, power management, and other control functions. Memory is used to store data used by the processor during operation.

[0080] Example 5:

[0081] Another embodiment of the present invention relates to a computer-readable storage medium storing a computer program. When executed by a processor, the computer program implements the initial velocity modeling method based on drilling information and geological strata described in the above embodiments.

[0082] That is, those skilled in the art will understand that all or part of the steps in the methods of the above embodiments can be implemented by a program instructing related hardware. This program is stored in a storage medium and includes several instructions to cause a device (which may be a microcontroller, chip, etc.) or processor to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0083] Example 6

[0084] Another embodiment of the present invention relates to a computer program product, including a computer program that, when executed by a processor, implements the steps of the initial velocity modeling method based on drilling information and geological strata described above.

[0085] Those skilled in the art will understand that the above embodiments are specific embodiments for implementing the present invention, and in practical applications, various changes in form and detail may be made without departing from the spirit and scope of the present invention.

Claims

1. A method for initial velocity modeling based on drilling information and geological strata, characterized in that, include: Determine the space well velocity curve based on drilling information from the target work area; The geological stratigraphic information obtained from field reconnaissance of the target work area is combined with the geological stratigraphic information obtained from seismic profiles to obtain the fused geological stratigraphic information. Extract structural continuity attributes from the fused geological stratigraphic information; The continuity property is used to guide the structural constraint interpolation of the space well velocity curve to obtain an initial velocity model that varies along the tectonic trend.

2. The initial velocity modeling method based on drilling information and geological strata according to claim 1, characterized in that, The process of determining the space well velocity curve based on drilling information from the target work area includes: Outlier removal and low-pass filtering were performed on the logging data of the target work area to obtain a spatial well velocity curve that conforms to the frequency band of the seismic processing. Based on the real coordinates of the well logging time series data and the grid coordinates of the target work area, the well logging discrete points are determined through coordinate mapping.

3. The initial velocity modeling method based on drilling information and geological strata according to claim 1, characterized in that, The process of fusing geological stratigraphic information obtained from field reconnaissance of the target work area with geological stratigraphic information picked up from seismic profiles to obtain fused geological stratigraphic information includes: Obtain geological profile image data of the target work area through field reconnaissance, and obtain the corresponding three-dimensional data volume of geological strata based on the geological profile image data; The corresponding three-dimensional geological stratigraphic data volume is obtained by picking the marker layer from the depth domain seismic profile results. The three-dimensional geological stratigraphic data obtained through field reconnaissance is weighted and fused with the three-dimensional geological stratigraphic data obtained through depth domain seismic profile results to obtain fused geological stratigraphic information.

4. The initial velocity modeling method based on drilling information and geological strata according to claim 3, characterized in that, The process involves weighted fusion of three-dimensional geological stratigraphic data obtained through field reconnaissance and three-dimensional geological stratigraphic data acquired through depth-domain seismic profiling to obtain fused geological stratigraphic information, including: After preserving the shallow portion of the three-dimensional geological stratigraphic data obtained through field reconnaissance, a weighted fusion of shallow, medium, and deep data is performed with the three-dimensional geological stratigraphic data obtained through depth-domain seismic profiles to obtain fused geological stratigraphic information.

5. The initial velocity modeling method based on drilling information and geological strata according to claim 1, characterized in that, The extraction of structural continuity attributes from the fused geological stratigraphic information includes: The fused geological stratigraphic information is used to perform boundary-preserving calculation of the three-dimensional spatial structure tensor, and the three-dimensional data volume of the geological stratigraphic continuity attribute of the target work area is extracted.

6. The initial velocity modeling method based on drilling information and geological strata according to claim 1, characterized in that, The method of using the continuity attribute to guide the structural constraint interpolation of the space well velocity curve includes: Based on the three-dimensional data volume of geological stratigraphic continuity attributes, the scattered data of the spatial well velocity curve near the stratigraphic structure are subjected to regional interpolation and smoothing to obtain an initial velocity model volume that varies along the tectonic trend.

7. The initial velocity modeling method based on drilling information and geological strata according to claim 1, characterized in that, The method further includes: The initial velocity model is used to perform depth domain velocity modeling.

8. An initial velocity modeling device based on drilling information and geological strata, characterized in that, include: The well logging data module is used to determine the spatial well velocity curve and well logging discrete sequence points based on the drilling information of the target work area; The geological stratigraphy module is used to merge the geological stratigraphy information of the target work area obtained through field reconnaissance with the geological stratigraphy information picked up through seismic profiles to obtain fused geological stratigraphy information. The attribute extraction module is used to extract structural continuity attributes from the fused geological stratigraphic information; The constraint interpolation module is used to guide the spatial well velocity curve to perform structural constraint interpolation using the continuity attribute, so as to obtain an initial velocity model that varies along the tectonic trend.

9. An electronic device, characterized in that, include: At least one processor; as well as, A memory communicatively connected to the at least one processor; wherein, The memory stores instructions that can be executed by the at least one processor to enable the at least one processor to perform the initial velocity modeling method based on drilling information and geological strata as described in any one of claims 1 to 7.

10. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the initial velocity modeling method based on drilling information and geological strata as described in any one of claims 1 to 7.

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