Crack prediction method, device, equipment and storage medium

Abstract

The embodiments of the present application provide a fracture prediction method, apparatus, device, and storage medium. The method includes: obtaining the intercept of self-excitation and self-collection, the azimuth of the fracture direction, and the anisotropic gradient corresponding to the prediction area; obtaining a fracture prediction result corresponding to the prediction area based on the intercept of self-excitation and self-collection, the azimuth of the fracture direction, and the anisotropic gradient through a fracture prediction transformation formula, wherein the fracture prediction result includes: the number of each fracture and the fracture location; outputting the fracture prediction result, which is used to adjust the drilling and completion operation plan, can obtain a more accurate prediction result, avoid the risk of well leakage, increase the density of the fracture network, and achieve increased production.

Description

Technical Field

[0001] The present application relates to the field of exploration technology, and in particular to a fracture prediction method, device, equipment and storage medium. Background Art

[0002] During drilling operations, problems such as wellbore collapse, stuck pipe, and fluid loss are common. The most common problem is drilling fluid loss. Once fluid loss occurs, the driller must be tripped on-site to assess the risk and cause of the loss, and the mud properties must be reconfigured. This is a time-consuming and labor-intensive process, seriously impacting drilling progress and increasing drilling costs. To mitigate the problem of fluid loss, fracture prediction is performed. However, fractures are small in size and have variable extension directions, making them difficult to identify.

[0003] The current fracture prediction method is based on the optimized combination of attributes of post-stack seismic data. Since post-stack seismic data is obtained by stacking pre-stack CRP gather data, the influence of formation anisotropy is eliminated during the stacking process. Since formations with fractures are anisotropic, fracture prediction using data that has eliminated anisotropy will result in large errors and may even produce false impressions. Summary of the Invention

[0004] The embodiments of the present application provide a crack prediction method, apparatus, device, and storage medium to solve the technical problem of large errors in existing crack prediction.

[0005] In a first aspect, an embodiment of the present application provides a crack prediction method, comprising:

[0006] Obtain the intercept of self-excited and self-collected fractures, the azimuth of the fracture strike, and the anisotropy gradient corresponding to the predicted area;

[0007] Obtaining a fracture prediction result corresponding to a prediction area through a fracture prediction transformation formula according to the intercept of the self-excitation and self-collection, the azimuth of the fracture strike, and the anisotropy gradient, wherein the fracture prediction result includes: the number of fractures and the position of the fractures;

[0008] The fracture prediction result is output, and the fracture prediction result is used for drilling and completion operations.

[0009] In a possible implementation, obtaining a fracture prediction result corresponding to a prediction area by using a fracture prediction transformation formula according to the self-excited self-collected intercept, the azimuth of the fracture strike, and the anisotropy gradient includes:

[0010] Substitute the anisotropic gradient and the intercept of the self-excitation and self-collection into the formula to calculate the ratio to eliminate the influence of the wavelet, and obtain the first result corresponding to the formula. Multiply the first result by the cosine of the azimuth angle of the crack direction to obtain the second result corresponding to the formula. The second result is the crack prediction result corresponding to the prediction area.

[0011] In a possible implementation, the crack prediction transformation formula is determined in the following manner:

[0012] Acquire pre-stack wide-azimuth seismic data and seismic velocity spectra, obtain synthetic seismic data based on the pre-stack wide-azimuth seismic data and well logging data, and obtain single-well layer velocity in the region based on the synthetic seismic data and wellside seismic data;

[0013] Correcting the seismic velocity spectrum using multiple single-well interval velocities in the region to obtain regional velocity volume data;

[0014] The velocity volume data is used to transform the pre-stack wide azimuth offset seismic data volume to obtain pre-stack wide azimuth gather seismic data;

[0015] Determining the intercept of self-excited self-collected waves, the azimuth of the fracture strike, and the anisotropy gradient corresponding to the region based on the pre-stack wide-azimuth gather seismic data;

[0016] Obtaining a fracture prediction result corresponding to the region according to the intercept of the self-excited self-collected fracture corresponding to the region, the azimuth angle of the fracture strike corresponding to the region, and the anisotropy gradient through an initial fracture prediction transformation formula;

[0017] The fracture prediction results corresponding to the region are used to verify the fracture development around the preset wells and obtain the prediction error;

[0018] If the prediction error is less than the preset error, the initial crack prediction transformation formula is used as the crack prediction transformation formula.

[0019] In a possible implementation, obtaining synthetic seismic data based on the pre-stack wide-azimuth seismic data and well logging data includes:

[0020] Obtaining seismic wavelets in the pre-stack wide-azimuth seismic data and reflection coefficients in the well logging data;

[0021] The seismic wavelet and the reflection coefficient are convolved to obtain synthesized seismic data.

[0022] In a possible implementation, obtaining the single-well layer velocity in the region based on the synthesized seismic data and the near-well seismic data includes:

[0023] Comparing the synthesized seismic data with the wellside seismic data based on the horizon to adjust the time of the synthesized seismic data and obtain a time-depth relationship of a single well in the region;

[0024] The time-depth relationship of a single well in the region is converted to obtain the interval velocity of the single well in the region.

[0025] In a possible implementation, determining the intercept of self-excited self-collected waves, the azimuth of the fracture strike, and the anisotropy gradient corresponding to the region based on the pre-stack wide-azimuth gather seismic data includes:

[0026] creating a left Pritzker equation group based on the pre-stack wide azimuth gather seismic data;

[0027] If the incident angle of the seismic wave in the region is less than a preset angle, a simplified set of equations is obtained according to the left Pritzker equations;

[0028] The simplified equation group is used to calculate the intercept of the self-excited self-collection corresponding to the region, the azimuth angle of the crack strike, and the anisotropy gradient.

[0029] In a possible implementation manner, before acquiring pre-stack wide-azimuth seismic data, the method further includes:

[0030] Acquiring pre-stack wide-azimuth seismic data to be processed, and performing noise reduction processing on the pre-stack wide-azimuth seismic data to be processed to obtain first pre-stack wide-azimuth seismic data;

[0031] The first pre-stack wide-azimuth seismic data is corrected for residual moveout using a sliding time window flattening method to obtain the pre-stack wide-azimuth seismic data.

[0032] In a second aspect, an embodiment of the present application provides a crack prediction device, comprising:

[0033] An acquisition unit is used to obtain the intercept of the self-excited and self-collected fractures, the azimuth of the fracture strike, and the anisotropy gradient corresponding to the predicted area;

[0034] a processing unit, configured to obtain a fracture prediction result corresponding to a prediction area according to the intercept of the self-excitation and self-collection, the azimuth of the fracture strike, and the anisotropy gradient using a fracture prediction transformation formula, wherein the fracture prediction result includes: the number of fractures and the position of the fractures;

[0035] The output unit is used to output the fracture prediction result, and the fracture prediction result is used for drilling and completion operations.

[0036] In one possible embodiment, the processing unit is also used to substitute the anisotropic gradient and the intercept of the self-excitation and self-collection into the crack prediction transformation formula to calculate a ratio to eliminate the influence of the wavelet, obtain a first result corresponding to the crack prediction transformation formula, and multiply the first result by the cosine of the azimuth angle of the crack direction to obtain a second result corresponding to the crack prediction transformation formula, and the second result is the crack prediction result corresponding to the prediction area.

[0037] In one possible embodiment, the processing unit is also used to obtain pre-stack wide-azimuth seismic data and seismic velocity spectrum, obtain synthetic seismic data based on the pre-stack wide-azimuth seismic data and logging data, and obtain single-well layer velocity in the region based on the synthetic seismic data and wellside seismic data; use multiple single-well layer velocities in the region to correct the seismic velocity spectrum to obtain regional velocity body data; use the velocity body data to convert the pre-stack wide-azimuth offset seismic data body to obtain pre-stack wide-azimuth angle gather seismic data; determine the intercept of the self-excited self-collection, the azimuth of the fracture strike and the anisotropic gradient corresponding to the region based on the pre-stack wide-azimuth angle gather seismic data; obtain the fracture prediction result corresponding to the region based on the intercept of the self-excited self-collection, the azimuth of the fracture strike and the anisotropic gradient corresponding to the region through the initial fracture prediction transformation formula; use the fracture prediction result corresponding to the region to verify the fracture development around the preset well to obtain the prediction error; if the prediction error is less than the preset error, the initial fracture prediction transformation formula is used as the fracture prediction transformation formula.

[0038] In a possible implementation, the processing unit is further configured to obtain seismic wavelets in the pre-stack wide-azimuth seismic data and reflection coefficients in the well logging data; and perform convolution processing on the seismic wavelets and the reflection coefficients to obtain synthesized seismic data.

[0039] In one possible embodiment, the processing unit is also used to compare the synthesized seismic data with the near-well seismic data based on the layer position to adjust the time of the synthesized seismic data and obtain the time-depth relationship of a single well in the area; and convert the time-depth relationship of a single well in the area to obtain the layer velocity of a single well in the area.

[0040] In one possible embodiment, the processing unit is also used to create a left Pritzker equation group based on the pre-stack wide azimuth gather seismic data; if the seismic wave incident angle in the area is less than a preset angle, a simplified equation group is obtained based on the left Pritzker equation group; and the simplified equation group is used to calculate the intercept of the self-excited self-collection, the azimuth of the crack direction, and the anisotropy gradient corresponding to the area.

[0041] In one possible embodiment, the processing unit is also used to obtain pre-stack wide-azimuth seismic data to be processed, perform noise reduction processing on the pre-stack wide-azimuth seismic data to be processed, and obtain first pre-stack wide-azimuth seismic data; and use a sliding time window flattening method to perform residual time difference correction on the first pre-stack wide-azimuth seismic data to obtain the pre-stack wide-azimuth seismic data.

[0042] In a third aspect, an embodiment of the present application provides an electronic device, comprising: a memory, a processor;

[0043] The memory stores computer-executable instructions;

[0044] The processor executes the computer-executable instructions stored in the memory, so that the processor executes the above first aspect and / or various possible implementations of the first aspect.

[0045] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, in which computer-executable instructions are stored. When the computer-executable instructions are executed by a processor, they are used to implement the first aspect above and / or various possible implementation methods of the first aspect.

[0046] In a fifth aspect, an embodiment of the present application provides a computer program product, including a computer program, which, when executed by a processor, implements the above first aspect and / or various possible implementation methods of the first aspect.

[0047] The fracture prediction method, apparatus, equipment and storage medium provided in the embodiments of the present application obtain the intercept of self-excitation and self-collection, the azimuth of the fracture direction and the anisotropic gradient corresponding to the prediction area, and obtain the fracture prediction results corresponding to the prediction area through the fracture prediction transformation formula based on the intercept of self-excitation and self-collection, the azimuth of the fracture direction and the anisotropic gradient, including: the number of each fracture and the position of the fracture, so as to obtain more accurate prediction results, avoid the risk of well leakage, improve the density of the fracture network, and achieve increased production. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0049] Figure 1 A schematic diagram of a scenario for the crack prediction method provided in this application;

[0050] Figure 2 Schematic diagram of the process of crack prediction method provided in this application Figure 1 ;

[0051] Figure 3 Schematic diagram of the process of crack prediction method provided in this application Figure 2 ;

[0052] Figure 4 Schematic diagram of the process of crack prediction method provided in this application Figure 3 ;

[0053] Figure 5 Comparison before and after correction for the remaining time difference;

[0054] Figure 6 A schematic diagram of the structure of the crack prediction device provided in this application;

[0055] Figure 7 This is a schematic diagram of the structure of the electronic device provided in this application.

[0056] The above drawings illustrate specific embodiments of the present application, which will be described in more detail below. These drawings and the textual description are not intended to limit the scope of the present application in any way, but rather to illustrate the concepts of the present application to those skilled in the art by reference to specific embodiments. DETAILED DESCRIPTION

[0057] Exemplary embodiments will be described in detail herein, with examples illustrated in the accompanying drawings. In the following description, when referring to the drawings, identical numerals in different figures represent identical or similar elements, unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all embodiments consistent with the present application. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present application, as detailed in the appended claims.

[0058] Figure 1 A schematic diagram of the crack prediction method provided in this application, such as Figure 1 As shown, the specific application scenarios of the present application include: an electronic device 101 and a server 102, and the electronic device 101 is in communication with the server 102. A client corresponding to the fracture prediction method is pre-installed in the electronic device 101. The user clicks the prediction button on the operation interface of the client, thereby triggering a prediction request. The server 102 responds to the fracture prediction request and obtains the intercept of the self-excitation and self-collection, the azimuth of the fracture direction and the anisotropic gradient corresponding to the prediction area; according to the intercept of the self-excitation and self-collection, the azimuth of the fracture direction and the anisotropic gradient, the fracture prediction result corresponding to the prediction area is obtained through the fracture prediction transformation formula, and the fracture prediction result includes: the number of each fracture and the position of the fracture; the fracture prediction result is output, and the fracture prediction result is used for drilling and completion operations.

[0059] Combining the above scenarios, it can be seen that the existing technology has a technical problem of large crack prediction errors.

[0060] The fracture prediction method provided in the present application obtains the intercept of self-excitation and self-collection, the azimuth of the fracture direction, and the anisotropic gradient corresponding to the prediction area, and obtains the fracture prediction results corresponding to the prediction area through the fracture prediction transformation formula based on the intercept of self-excitation and self-collection, the azimuth of the fracture direction, and the anisotropic gradient, including: the number of each fracture and the position of the fracture. It can obtain more accurate prediction results, avoid the risk of well leakage, improve the density of the fracture network, and achieve increased production.

[0061] The following specific embodiments describe in detail the technical solution of the present application and how the technical solution of the present application solves the above-mentioned technical problems. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0062] Figure 2 Schematic diagram of the process of crack prediction method provided in this application Figure 1 ,like Figure 2 As shown, the method includes:

[0063] Step 201: Obtain the intercept of the self-excited and self-collected fractures, the azimuth angle of the fracture strike, and the anisotropy gradient corresponding to the predicted area.

[0064] In this embodiment, the corresponding self-excited self-collected intercept, fracture strike azimuth, and anisotropic gradient of the predicted area are obtained through inversion, wherein the anisotropic gradient refers to a gradient with different characteristics in different directions.

[0065] Step 202 : Obtain the fracture prediction result corresponding to the prediction area by using the fracture prediction transformation formula according to the intercept of the self-excitation and self-collection, the azimuth of the fracture trend, and the anisotropy gradient. The fracture prediction result includes: the number of fractures and the fracture positions.

[0066] In this embodiment, the intercept of self-excitation and self-collection, the azimuth of the fracture direction and the anisotropy gradient are substituted into the fracture prediction transformation formula to calculate the fracture prediction results corresponding to the prediction area. The use of the formula can eliminate the influence of seismic wavelets, where the fracture prediction results include: the number of each fracture and the location of the fracture.

[0067] Step 203: Output the fracture prediction result, which is used for drilling and completion operations.

[0068] In this embodiment, the fracture prediction results are output, and a drilling and completion plan is prepared using the fracture prediction results to perform drilling operations. The drilling project plan designed based on the fracture prediction results effectively avoids the impact of formation leakage.

[0069] The fracture prediction method provided in the embodiment of the present application obtains the intercept of self-excitation and self-collection, the azimuth of the fracture direction, and the anisotropic gradient corresponding to the prediction area, and obtains the fracture prediction results corresponding to the prediction area through the fracture prediction transformation formula based on the intercept of self-excitation and self-collection, the azimuth of the fracture direction, and the anisotropic gradient, including: the number of each fracture and the position of the fracture. Therefore, the drilling engineering plan designed according to the fracture prediction results effectively avoids the influence of formation leakage, can obtain more accurate prediction results, and can avoid the risk of well leakage, improve the density of the fracture network, and achieve increased production.

[0070] Figure 3 Schematic diagram of the process of crack prediction method provided in this application Figure 2 ,like Figure 3 As shown, this embodiment Figure 2 Based on the embodiment, the crack prediction method is described in detail, and the method includes:

[0071] Step 301: Obtain the intercept of the self-excited and self-collected fractures, the azimuth angle of the fracture strike, and the anisotropy gradient corresponding to the predicted area.

[0072] In this embodiment, the corresponding intercept of the self-excited self-collected cracks, the azimuth angle of the crack strike, and the anisotropy gradient of the predicted area are obtained.

[0073] Step 302: Substitute the anisotropic gradient and the intercept of the self-excitation and self-collection into the crack prediction transformation formula to calculate the ratio to eliminate the influence of the wavelet, obtain the first result corresponding to the crack prediction transformation formula, and multiply the first result by the cosine of the azimuth angle of the crack direction to obtain the second result corresponding to the crack prediction transformation formula. The second result is the crack prediction result corresponding to the prediction area.

[0074] In this embodiment, the intercept of the self-excitation and self-collection, the azimuth of the crack strike, and the anisotropy gradient are substituted into the crack prediction transformation formula to calculate the crack prediction result corresponding to the prediction area. The crack prediction transformation formula is expressed as:

[0075]

[0076] Among them, F v is the crack prediction result, including: the number of cracks and the location of the cracks, B ani is the anisotropy gradient, A is the intercept of self-excitation and self-collection, is the azimuth of the crack direction.

[0077] Step 303: Output the fracture prediction result, which is used for drilling and completion operations.

[0078] In this embodiment, the fracture prediction results are output, and a drilling and completion plan is prepared using the fracture prediction results to perform drilling operations. The drilling project plan designed based on the fracture prediction results effectively avoids the impact of formation leakage.

[0079] In this embodiment, based on the fracture prediction results, the designed drilling engineering plan effectively avoids the influence of formation leakage and can obtain relatively accurate prediction results.

[0080] Figure 4 Schematic diagram of the process of crack prediction method provided in this application Figure 3 ,like Figure 4 As shown, this embodiment Figure 2 or Figure 3 Based on the embodiment, the crack prediction transformation formula is described in detail. The crack prediction transformation formula is determined by the following method:

[0081] Step 401 , obtain pre-stack wide-azimuth seismic data and seismic velocity spectrum, obtain synthesized seismic data based on the pre-stack wide-azimuth seismic data and well logging data, and obtain single-well layer velocity in the region based on the synthesized seismic data and wellside seismic data.

[0082] In this embodiment, pre-stack wide-azimuth seismic data and seismic velocity spectra are obtained, and synthesized based on the pre-stack wide-azimuth seismic data and logging data to obtain synthesized seismic data. By comparing the synthesized seismic data with the wellside seismic data, the time-depth relationship of a single well in the region is obtained, and the single-well layer velocity in the region is obtained based on the single-well time-depth relationship.

[0083] Optionally, before obtaining pre-stack wide-azimuth seismic data, the method further includes:

[0084] Obtain pre-stack wide-azimuth seismic data to be processed, perform noise reduction processing on the pre-stack wide-azimuth seismic data to be processed, and obtain first pre-stack wide-azimuth seismic data; use a sliding time window flattening method to perform residual moveout correction on the first pre-stack wide-azimuth seismic data to obtain pre-stack wide-azimuth seismic data.

[0085] In this embodiment, pre-stack wide-azimuth seismic data to be processed is obtained, and noise reduction processing is performed on the pre-stack wide-azimuth seismic data to be processed to improve the signal-to-noise ratio. For example, while-drilling noise removal algorithms such as wavelet transform, singular value decomposition and adaptive filtering are used to improve the seismic signal-to-noise ratio. The first pre-stack wide-azimuth seismic data is obtained, and the first pre-stack wide-azimuth seismic data is corrected for residual time difference using a sliding time window flattening method, thereby obtaining pre-stack wide-azimuth seismic data and improving the anisotropic sensitivity of the data.

[0086] Optionally, the pre-stack wide azimuth seismic data to be processed are screened to obtain preferred pre-stack wide azimuth seismic data. Due to the inherent limitations of azimuth data acquisition, the coverage times are unevenly distributed in certain azimuths and offset distances. Data channels with more coverage times in azimuths and offset distances are preferred. The screened pre-stack wide azimuth seismic data are subjected to noise reduction processing to obtain first pre-stack wide azimuth seismic data. The first pre-stack wide azimuth seismic data are corrected for residual time difference using a sliding time window flattening method, thereby obtaining pre-stack wide azimuth seismic data.

[0087] In one possible implementation, synthesized seismic data is obtained based on pre-stack wide-azimuth seismic data and well logging data, including:

[0088] Seismic wavelets from pre-stack wide-azimuth seismic data and reflection coefficients from well logging data are obtained; the seismic wavelets and reflection coefficients are convolved to obtain synthesized seismic data.

[0089] In this embodiment, seismic wavelets in pre-stack wide-azimuth seismic data and reflection coefficients in well logging data are obtained, and synthesized seismic data are obtained by convolution processing of the seismic wavelets in pre-stack wide-azimuth seismic data and the reflection coefficients in well logging data.

[0090] In one possible implementation, obtaining single-well interval velocity in a region based on synthesized seismic data and near-well seismic data includes:

[0091] The synthesized seismic data are compared with the wellside seismic data based on the horizon to adjust the time of the synthesized seismic data and obtain the time-depth relationship of a single well in the region; the time-depth relationship of a single well in the region is converted to obtain the layer velocity of a single well in the region.

[0092] In this embodiment, the synthesized seismic data is compared with the near-well seismic data based on the layer, so as to adjust the time of the synthesized seismic data. For example, the time corresponding to a certain layer in the synthesized seismic data is 1550ms, while the time corresponding to the same layer in the near-well seismic data is 1558ms. The time of the layer in the synthesized seismic data is adjusted to 1558ms, so as to obtain the time-depth relationship of a single well in the region, and convert the time-depth relationship of a single well in the region. Specifically, with the time-depth relationship, the depth divided by the time equals the velocity, and the velocity of the single well layer in the region is obtained.

[0093] Step 402: Correct the seismic velocity spectrum using multiple single-well interval velocities in the region to obtain regional velocity volume data.

[0094] In this embodiment, the seismic velocity spectrum is corrected using the velocities of multiple single-well layers in the region to obtain regional velocity volume data. For example, the velocity of the Minghua Town Formation at Well A is 3500 m / s, and the corresponding seismic velocity spectrum is 3550 m / s. Therefore, the seismic velocity of this place is modified to 3500 m / s to obtain regional velocity volume data.

[0095] Step 403: Use the velocity volume data to transform the pre-stack wide azimuth offset seismic data volume to obtain pre-stack wide azimuth gather seismic data.

[0096] In this embodiment, the pre-stack wide azimuth offset seismic data volume AVOZ is converted using velocity volume data to obtain pre-stack wide azimuth gather seismic data AVAZ.

[0097] Step 404 : Determine the intercept of the self-excited and self-collected fractures, the azimuth of the fracture strike, and the anisotropy gradient corresponding to the region based on the pre-stack wide-azimuth gather seismic data.

[0098] In this embodiment, the intercept of the self-excited self-collected wave, the azimuth of the fracture strike, and the anisotropy gradient corresponding to the region can be calculated using the pre-stack wide azimuth gather seismic data AVAZ.

[0099] In one possible implementation, determining the intercept of self-excited self-collected data, the azimuth of the fracture strike, and the anisotropy gradient corresponding to a region based on pre-stack wide-azimuth gather seismic data includes:

[0100] A left-Pritzker equation group is created based on pre-stack wide-azimuth gather seismic data. If the seismic wave incident angle in the region is less than the preset angle, a simplified equation group is obtained based on the left-Pritzker equation group. The simplified equation group is used to calculate the azimuth angle and anisotropy gradient of the fracture strike corresponding to the region.

[0101] In this embodiment, the left Pritzker equations are established based on the AVAZ data volume. The left Pritzker equations are as follows:

[0102]

[0103] Where θ represents the incident angle of the seismic wave, The azimuth of the crack direction, Indicates the azimuth of the survey line; is the azimuth of the survey line relative to the fracture direction, α is the P-wave velocity, Δα is the P-wave velocity difference above and below the formation interface, G is the S-wave velocity, ΔG is the S-wave velocity difference above and below the formation interface, β is the S-wave velocity of the surface formation, and Δε is the S-wave velocity of the surface formation. V , Δδ V , Δγ are anisotropic model parameters obtained through rock mechanics experiments, and the anisotropic parameters are different in different regions.

[0104] Furthermore, when the incident angle of the seismic wave in the region is small, formula (2) is simplified to obtain a simplified formula, which is expressed as:

[0105]

[0106] in, Where v is the velocity, ΔV is the velocity difference between the upper and lower interfaces, ρ is the density, Δρ is the density difference between the upper and lower interfaces, and A is the intercept of self-excitation and self-collection. is an isotropic gradient, is the anisotropic gradient. Based on the seismic wave data at different azimuths and incident angles, the intercept of the self-excited and self-collected fractures, the azimuth of the fracture strike, the anisotropic gradient and the isotropic gradient corresponding to the region are obtained by inversion calculation using formula (3). Formula (3) is the Ruger equation.

[0107] Step 405 , obtaining a fracture prediction result corresponding to the region by using an initial fracture prediction transformation formula according to the intercept of the self-excited self-collected fracture corresponding to the region, the azimuth angle of the fracture strike corresponding to the region, and the anisotropy gradient.

[0108] In this embodiment, the intercept of the self-excitation and self-collection corresponding to the region, the azimuth angle of the crack strike corresponding to the region, and the anisotropy gradient are substituted into the initial crack prediction transformation formula to obtain the crack prediction result corresponding to the region. The initial crack prediction transformation formula is expressed as:

[0109]

[0110] It should be noted that the parameters of formula (1) and formula (4) are the same. When the prediction results are relatively accurate, the initial crack prediction transformation formula is used in the actual prediction.

[0111] Step 406 : Using the fracture prediction results corresponding to the region, verify the fracture development around the preset well to obtain the prediction error.

[0112] In this embodiment, the fracture prediction result corresponding to the region verifies the fracture development around the preset well. If the prediction error is greater than or equal to the preset error, the process returns to the step of performing noise reduction processing on the wide-azimuth seismic data to be processed to adjust the signal-to-noise ratio.

[0113] Step 407: If the prediction error is less than the preset error, the initial crack prediction transformation formula is used as the crack prediction transformation formula.

[0114] In this embodiment, if the prediction error is less than the preset error, the initial crack prediction transformation formula is used as the crack prediction transformation formula. For example, there are 10 predicted cracks, 9 of which coincide with the actual cracks, and the prediction error is 10%. If the preset error is 20%, the initial crack prediction transformation formula is used as the crack prediction transformation formula, where the preset error is set according to the actual situation and is not limited to the above-mentioned values.

[0115] Optionally, during the drilling process, if there is a deviation in the fracture prediction results, the seismic data is recalibrated using a new well, that is, the step of obtaining synthetic seismic data based on pre-stack wide-azimuth seismic data and logging data is returned until it matches the actual drilling results.

[0116] In this embodiment, based on the fracture prediction results, the designed drilling engineering plan effectively avoids the influence of formation leakage, can obtain relatively accurate prediction results, and can avoid the risk of well leakage, increase the density of the fracture network, and achieve increased production.

[0117] Example 1:

[0118] The technology of the present invention is explained using a horizontal well in a certain block as an example. The block where this well is located has serious leakage, and there are leakages in multiple layers. Oil and gas are verified by leakage in the target layer's appendages, which seriously delays the drilling progress. Before drilling, the surrounding adjacent wells all used superimposed data to predict cracks, but the prediction results had a large error compared to the actual drilled cracks, and the formulated drilling engineering plan also had deviations, so leakage verification was required. Before drilling this well, the present invention was used to predict cracks, and a drilling engineering construction plan was formulated accordingly. Although there were leakages during drilling, the leakage in the same layer was reduced by 90% compared to the adjacent wells, greatly shortening the drilling cycle.

[0119] Step 1: Obtain pre-stack wide-azimuth seismic data to be processed, filter the pre-stack wide-azimuth seismic data to be processed, and obtain filtered pre-stack wide-azimuth seismic data.

[0120] Step 2: Perform noise reduction processing on the filtered pre-stack wide-azimuth seismic data to obtain the first pre-stack wide-azimuth seismic data; use the sliding time window flattening method to perform residual moveout correction on the first pre-stack wide-azimuth seismic data to obtain the pre-stack wide-azimuth seismic data.

[0121] See also Figure 5 , Figure 5 The figure shows the azimuth data before and after the residual time difference correction. The corrected data can identify anisotropic features. The horizontal axis is the incident angle and the vertical axis is the time.

[0122] Step 3: Obtain pre-stack wide-azimuth seismic data and seismic velocity spectrum, obtain synthetic seismic data based on pre-stack wide-azimuth seismic data and well logging data, and obtain single-well layer velocity in the area based on the synthetic seismic data and wellside seismic data.

[0123] Step 4: Use multiple single-well layer velocities in the region to correct the seismic velocity spectrum and obtain regional velocity volume data.

[0124] Step 5: Use the velocity volume data to transform the pre-stack wide azimuth offset seismic data volume to obtain pre-stack wide azimuth gather seismic data.

[0125] Step 7: Determine the intercept of the self-excited and self-collected fractures, the azimuth of the fracture strike, and the anisotropy gradient corresponding to the region based on the pre-stack wide-azimuth gather seismic data.

[0126] Step 8: Obtain the fracture prediction result corresponding to the region by using the initial fracture prediction transformation formula according to the intercept of the self-excited self-collection corresponding to the region, the azimuth angle of the fracture strike corresponding to the region, and the anisotropy gradient.

[0127] Step 9: Use the fracture prediction results corresponding to the region to verify the fracture development around the preset well and obtain the prediction error;

[0128] Step 10: If the prediction error is less than the preset error, the initial crack prediction transformation formula is used as the crack prediction transformation formula.

[0129] Step 11: Obtain the intercept of the self-excited and self-collected fractures, the azimuth of the fracture strike, and the anisotropy gradient corresponding to the predicted area;

[0130] Step 12: Based on the intercept of the self-excitation and self-collection, the azimuth of the crack direction and the anisotropy gradient, the crack prediction results corresponding to the prediction area are obtained through the crack prediction transformation formula. The crack prediction results include: the number of each crack and the crack location;

[0131] Step 13: Output the fracture prediction results, which are used for drilling and completion operations.

[0132] Table 1 shows the same set of fracture predictions. Wells X1, X2, and X3, using conventional methods, showed significant discrepancies between the predicted and actual fracture counts observed during logging. Consequently, the drilling plan used inappropriate mud properties, resulting in significant mud losses and prolonged plugging. However, Well H5, using this method, predicted fracture counts and locations that closely matched the data. Furthermore, based on these fracture predictions, the drilling mud properties were re-adjusted, resulting in only leakage and a loss of 0.75 m³ of mud. Furthermore, the leak was successfully plugged on-site in just three hours, and drilling resumed.

[0133] Table 1 Prediction of formation fractures in the same set

[0134]

[0135] During the fracturing design of this well, the fracture development and distribution patterns predicted by this method were used to redesign the fracturing scheme, simulate the fracture network initiation and development conditions, and implement staged fracturing during acid fracturing construction. Finally, the test oil production of this well reached 156 tons / day, far exceeding the design expectations, achieving the reservoir design goals, and helping the block's production to meet the target.

[0136] Figure 6 A schematic diagram of the structure of the crack prediction device provided in this application is shown in FIG. Figure 6 As shown, the crack prediction device 60 provided in this embodiment includes:

[0137] The acquisition unit 601 is used to obtain the intercept of the self-excited and self-received oscillations, the azimuth of the fracture strike, and the anisotropy gradient corresponding to the prediction area. The processing unit 602 is used to apply the fracture prediction transformation formula based on the intercept of the self-excited and self-received oscillations, the azimuth of the fracture strike, and the anisotropy gradient to obtain the fracture prediction results corresponding to the prediction area. The fracture prediction results include the number of fractures and their locations. The output unit 603 is used to output the fracture prediction results, which are used for drilling and completion operations.

[0138] In one possible implementation, the processing unit 602 is also used to substitute the anisotropic gradient and the intercept of the self-excitation and self-collection into the crack prediction transformation formula to calculate the ratio to eliminate the influence of the wavelet, obtain the first result corresponding to the crack prediction transformation formula, and multiply the first result by the cosine of the azimuth angle of the crack direction to obtain the second result corresponding to the crack prediction transformation formula, and the second result is the crack prediction result corresponding to the prediction area.

[0139] In one possible implementation, the processing unit 602 is also used to obtain pre-stack wide-azimuth seismic data and seismic velocity spectrum, obtain synthesized seismic data based on the pre-stack wide-azimuth seismic data and well logging data, and obtain single-well layer velocity in the region based on the synthesized seismic data and wellside seismic data; use multiple single-well layer velocities in the region to correct the seismic velocity spectrum to obtain regional velocity body data; use the velocity body data to convert the pre-stack wide-azimuth offset distance seismic data body to obtain pre-stack wide-azimuth angle gather seismic data; determine the intercept of self-excitation and self-collection, the azimuth of the fracture direction and the anisotropy gradient corresponding to the region based on the pre-stack wide-azimuth angle gather seismic data; obtain the fracture prediction result corresponding to the region through the initial fracture prediction transformation formula based on the intercept of self-excitation and self-collection, the azimuth of the fracture direction and the anisotropy gradient corresponding to the region; use the fracture prediction result corresponding to the region to verify the fracture development around the preset well and obtain the prediction error; if the prediction error is less than the preset error, the initial fracture prediction transformation formula is used as the fracture prediction transformation formula.

[0140] In a possible implementation, the processing unit 602 is further configured to obtain seismic wavelets from pre-stack wide-azimuth seismic data and reflection coefficients from well logging data; and perform convolution processing on the seismic wavelets and the reflection coefficients to obtain synthesized seismic data.

[0141] In one possible implementation, the processing unit 602 is also used to compare the synthesized seismic data with the near-well seismic data based on the layer position to adjust the time of the synthesized seismic data and obtain the time-depth relationship of a single well in the region; and to convert the time-depth relationship of a single well in the region to obtain the layer velocity of a single well in the region.

[0142] In one possible implementation, the processing unit 602 is also used to create a left Pritzker equation group based on pre-stack wide-azimuth gather seismic data; if the seismic wave incident angle of the region is less than a preset angle, a simplified equation group is obtained based on the left Pritzker equation group; the simplified equation group is used to calculate the intercept of the self-excited self-collection, the azimuth of the fracture direction, and the anisotropy gradient corresponding to the region.

[0143] In one possible implementation, the processing unit 602 is also used to obtain pre-stack wide-azimuth seismic data to be processed, perform noise reduction processing on the pre-stack wide-azimuth seismic data to be processed, and obtain first pre-stack wide-azimuth seismic data; and use a sliding time window flattening method to perform residual time difference correction on the first pre-stack wide-azimuth seismic data to obtain pre-stack wide-azimuth seismic data.

[0144] The crack prediction device provided in this embodiment can execute the method provided in the above method embodiment. Its implementation principle and technical effects are similar, and will not be described in detail in this embodiment.

[0145] Figure 7 This is a schematic diagram of the structure of the electronic device provided in this application. Figure 7 As shown, the electronic device 70 provided in this embodiment includes: at least one processor 701 and a memory 702. Optionally, the device 70 further includes a communication component 703. The processor 701, the memory 702 and the communication component 703 are connected via a bus 704.

[0146] During the specific implementation process, at least one processor 701 executes the computer-executable instructions stored in the memory 702, so that the at least one processor 701 performs the above method.

[0147] The specific implementation process of the processor 701 can be found in the above method embodiment. Its implementation principle and technical effects are similar and will not be repeated here in this embodiment.

[0148] In the above embodiments, it should be understood that the processor may be a central processing unit (CPU), other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), etc. A general-purpose processor may be a microprocessor or any conventional processor. The steps of the method disclosed in the present invention may be directly implemented by a hardware processor or implemented by a combination of hardware and software modules in the processor.

[0149] The memory may include a high-speed memory (Random Access Memory, RAM), and may also include a non-volatile memory (NVM), such as at least one disk memory.

[0150] The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus. Buses can be classified into address buses, data buses, and control buses. For ease of illustration, the buses in the drawings of this application are not limited to just one bus or just one type of bus.

[0151] The present application also provides a computer program product, including a computer program, which implements the above method when executed by a processor.

[0152] The present application also provides a computer-readable storage medium, in which computer-executable instructions are stored. When a processor executes the computer-executable instructions, the above method is implemented.

[0153] The above-mentioned readable storage medium can be implemented by any type of volatile or non-volatile memory device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic memory, flash memory, magnetic disk or optical disk. The readable storage medium can be any available medium that can be accessed by a general-purpose or special-purpose computer.

[0154] An exemplary readable storage medium is coupled to a processor so that the processor can read information from the readable storage medium and write information to the readable storage medium. Of course, the readable storage medium can also be an integral part of the processor. The processor and the readable storage medium can be located in an application specific integrated circuit (ASIC). Of course, the processor and the readable storage medium can also exist in the device as discrete components.

[0155] The division of units is merely a logical functional division; actual implementations may employ alternative divisions, such as combining or integrating multiple units or components into another system, or omitting or disabling certain features. Furthermore, any direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection between devices or units, either through an interface, electrical, mechanical, or other means.

[0156] Units described as separate components may or may not be physically separate, and components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0157] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0158] If the function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the various embodiments of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, and other media that can store program code.

[0159] Those skilled in the art will appreciate that all or part of the steps in the above-described method embodiments can be implemented using hardware associated with program instructions. The aforementioned program can be stored in a computer-readable storage medium. When executed, the program performs the steps of the above-described method embodiments. The aforementioned storage medium includes various media capable of storing program code, such as ROM, RAM, magnetic disks, or optical disks.

[0160] Finally, it should be noted that those skilled in the art will readily identify other embodiments of the present invention after considering the specification and practicing the invention disclosed herein. The present invention is intended to cover any variations, uses, or adaptations of the present invention that follow the general principles of the present invention and include common knowledge or customary techniques in the art not disclosed herein. The present invention is not limited to the precise structure described above and illustrated in the accompanying drawings, and various modifications and variations may be made without departing from the scope thereof. The scope of the present invention is limited solely by the appended claims.

Claims

1. A crack prediction method, characterized in that: include: Obtain the intercept of self-excited and self-collected fractures, the azimuth of the fracture strike, and the anisotropy gradient corresponding to the predicted area; Obtaining a fracture prediction result corresponding to a prediction area through a fracture prediction transformation formula according to the intercept of the self-excitation and self-collection, the azimuth of the fracture strike, and the anisotropy gradient, wherein the fracture prediction result includes: the number of fractures and the position of the fractures; Outputting the fracture prediction result, wherein the fracture prediction result is used for drilling and completion operations; The method of obtaining a fracture prediction result corresponding to a prediction area by using a fracture prediction transformation formula according to the intercept of the self-excitation and self-collection, the azimuth of the fracture strike, and the anisotropy gradient includes: Substitute the anisotropic gradient and the intercept of the self-excitation and self-collection into the crack prediction transformation formula to calculate the ratio to eliminate the influence of the wavelet, and obtain the first result corresponding to the crack prediction transformation formula. Multiply the first result by the cosine of the azimuth angle of the crack direction to obtain the second result corresponding to the crack prediction transformation formula. The second result is the crack prediction result corresponding to the prediction area.

2. The method according to claim 1, characterized in that The crack prediction transformation formula is determined by the following method: Acquire pre-stack wide-azimuth seismic data and seismic velocity spectra, obtain synthetic seismic data based on the pre-stack wide-azimuth seismic data and well logging data, and obtain single-well layer velocity in the region based on the synthetic seismic data and wellside seismic data; Correcting the seismic velocity spectrum using multiple single-well interval velocities in the region to obtain regional velocity volume data; The velocity volume data is used to transform the pre-stack wide azimuth offset seismic data volume to obtain pre-stack wide azimuth gather seismic data; Determining the intercept of self-excited self-collected waves, the azimuth of the fracture strike, and the anisotropy gradient corresponding to the region based on the pre-stack wide-azimuth gather seismic data; Obtaining a fracture prediction result corresponding to the region according to the intercept of the self-excited self-collected fracture corresponding to the region, the azimuth angle of the fracture strike corresponding to the region, and the anisotropy gradient through an initial fracture prediction transformation formula; The fracture prediction results corresponding to the region are used to verify the fracture development around the preset wells and obtain the prediction error; If the prediction error is less than the preset error, the initial crack prediction transformation formula is used as the crack prediction transformation formula.

3. The method according to claim 2, characterized in that The step of obtaining synthesized seismic data based on the pre-stack wide-azimuth seismic data and the well logging data comprises: Obtaining seismic wavelets in the pre-stack wide-azimuth seismic data and reflection coefficients in the well logging data; The seismic wavelet and the reflection coefficient are convolved to obtain synthesized seismic data.

4. The method according to claim 2, characterized in that The obtaining of single well layer velocity in the region based on the synthesized seismic data and wellside seismic data includes: Comparing the synthesized seismic data with the wellside seismic data based on the horizon to adjust the time of the synthesized seismic data and obtain a time-depth relationship of a single well in the region; The time-depth relationship of a single well in the region is converted to obtain the interval velocity of the single well in the region.

5. The method according to claim 2, characterized in that Determining the intercept of self-excited self-collected waves, the azimuth of the fracture strike, and the anisotropy gradient corresponding to the region based on the pre-stack wide-azimuth gather seismic data includes: creating a left Pritzker equation group based on the pre-stack wide azimuth gather seismic data; If the incident angle of the seismic wave in the region is less than a preset angle, a simplified set of equations is obtained according to the left Pritzker equations; The simplified equation group is used to calculate the intercept of the self-excited self-collection corresponding to the region, the azimuth angle of the crack strike, and the anisotropy gradient.

6. The method according to claim 2, characterized in that Before acquiring pre-stack wide-azimuth seismic data, the method further includes: Acquiring pre-stack wide-azimuth seismic data to be processed, and performing noise reduction processing on the pre-stack wide-azimuth seismic data to be processed to obtain first pre-stack wide-azimuth seismic data; The first pre-stack wide-azimuth seismic data is corrected for residual moveout using a sliding time window flattening method to obtain the pre-stack wide-azimuth seismic data.

7. A crack prediction device, characterized in that: include: An acquisition unit is used to obtain the intercept of the self-excited and self-collected fractures, the azimuth of the fracture strike, and the anisotropy gradient corresponding to the predicted area; a processing unit, configured to obtain a fracture prediction result corresponding to a prediction area according to the intercept of the self-excitation and self-collection, the azimuth of the fracture strike, and the anisotropy gradient using a fracture prediction transformation formula, wherein the fracture prediction result includes: the number of fractures and the position of the fractures; An output unit, configured to output the fracture prediction result, wherein the fracture prediction result is used for drilling and completion operations; The processing unit is specifically used to substitute the anisotropic gradient and the intercept of the self-excitation and self-collection into the crack prediction transformation formula to calculate a ratio to eliminate the influence of the wavelet, obtain a first result corresponding to the crack prediction transformation formula, and multiply the first result by the cosine of the azimuth angle of the crack direction to obtain a second result corresponding to the crack prediction transformation formula, and the second result is the crack prediction result corresponding to the prediction area.

8. An electronic device, characterized in that: include: Memory, processor; The memory stores computer-executable instructions; The processor executes the computer-executable instructions stored in the memory, so that the processor performs the method according to any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that The computer-readable storage medium stores computer-executable instructions, which are used to implement the method according to any one of claims 1 to 6 when executed by a processor.

Images