Anisotropy parameter calculation method and device based on VVAZ and AVAZ joint inversion

Abstract

The invention relates to the technical field of seismic exploration, and particularly discloses a VVAZ and AVAZ combined inversion anisotropy parameter calculation method and device, and the method comprises the steps: carrying out the VVAZ inversion of a five-dimensional pre-stack gather, and obtaining an anisotropy parameter delta; carrying out residual time difference correction on the five-dimensional pre-stack gather to obtain a corrected five-dimensional pre-stack gather; aVAZ inversion is carried out on the corrected five-dimensional pre-stack gather, and anisotropic fracture parameters are obtained; based on logging information of the work area, elastic parameter inversion is carried out on the corrected five-dimensional pre-stack gather, and the longitudinal and transverse wave velocity ratio of the work area is obtained; and solving anisotropy parameters delta N and delta T based on the anisotropy parameter delta, the anisotropy crack parameter and the longitudinal and transverse wave velocity ratio. According to the method, rapid solving of fracture anisotropy parameters deltaN and deltaT is achieved by utilizing the solving relation of anisotropy parameters of VVAZ and AVAZ and the relation among the Thomsen anisotropy parameter delta, the Schobergn anisotropy parameters deltaN and deltaT and the anisotropy gradient Bani.

Description

Technical Field

[0001] This invention relates to the field of seismic exploration technology, specifically to a method and apparatus for calculating anisotropy parameters by joint inversion of VVAZ and AVAZ. Background Technology

[0002] With the development and popularization of "wide-angle and high-angle" acquisition technologies both domestically and internationally, P-wave (P-wave is longitudinal wave) azimuth anisotropy fracture prediction technology based on wide-angle gathers has become increasingly mature. P-wave azimuth anisotropy techniques can be categorized into two types based on the type of seismic data: velocity (or time difference) and amplitude. Techniques based on P-wave azimuth velocity variations are generally called VVAZ (Velocity Variations with Azimuth), while techniques based on P-wave azimuth amplitude variations are generally called AVAZ (Amplitude Variation with Azimuth). There are many types of AVAZ anisotropy inversion techniques. Early techniques included ellipse fitting; later, Ruger approximation formulas and azimuth Fourier series inversion techniques were developed; and in recent years, AVAZ inversion techniques based on fracture rock physics models have also been developed.

[0003] In existing technologies, the Thomsen anisotropy parameter δ can be obtained based on the fast and slow P-waves in VVAZ, and the anisotropy gradient Bani can be obtained based on the Ruger formula inversion technique of AVAZ. However, the Schobergn anisotropy parameter Δ can be obtained directly by calculation. N and Δ T That would be more difficult.

[0004] Note 1: TI (Transverse Isotroic) is short for transversely isotropic medium, and HTI (Horizontal Transverse Isotroic) is short for transversely isotropic medium with a horizontal axis of symmetry.

[0005] Note 2: Anisotropy parameters, based on different fundamental theories and hypothetical models, can be divided into Thomsen parameters, namely ε, δ, and γ. Parameter ε describes the small difference between the horizontal and vertical P-wave velocities, δ represents the velocity difference between fast and slow P-waves along the incident angle, and γ defines the difference between fast and slow shear waves in the horizontal direction.

[0006] Schoenberg anisotropy parameter, Δ N and Δ T , where Δ N Δ represents a reflection of the normal force in a rock fissure. T This indicates a response of rock fissures to shear forces.

[0007] Note 3: The front-stack azimuth gather in this application can be either an azimuth angle gather or an azimuth offset gather. In practical applications, azimuth angle gathers and azimuth offset gathers are often two different representations of the same gather data, and they can be converted to each other: the first-hand seismic data collected in actual field seismic exploration is in the form of azimuth offset gathers, but azimuth angle gathers are often used in later inversion applications. Azimuth offset gathers can be converted into azimuth angle gathers using velocity data from seismic exploration.

[0008] Based on this technical background, this invention studies a method and apparatus for calculating anisotropy parameters by joint inversion of VVAZ and AVAZ. Summary of the Invention

[0009] To address the shortcomings of existing technologies, this invention provides a method and apparatus for calculating anisotropy parameters using joint VVAZ and AVAZ inversion. Based on the anisotropy results from VVAZ and AVAZ inversion, this method can calculate the anisotropy parameter Δ of the Schobergn crack. N and Δ T Fast calculation based on Δ N and Δ T The calculation results can be used to directly calculate the horizontal stress change rate or reservoir characteristic parameters such as the fluid identification factor containing fracture parameters, and then construct a refined description of five-dimensional seismic data for different types of reservoirs.

[0010] To achieve the above objectives, a first aspect of the present invention provides a method for calculating anisotropy parameters through joint inversion of VVAZ and AVAZ, comprising:

[0011] Five-dimensional pre-stack gathers are obtained by processing seismic data;

[0012] The anisotropy parameter δ is obtained by performing VVAZ inversion on the five-dimensional pre-stack gather;

[0013] The remaining time difference is corrected by performing residual time difference correction on the five-dimensional pre-stack gather to obtain the corrected five-dimensional pre-stack gather;

[0014] AVAZ inversion was performed on the corrected five-dimensional pre-stack gather to obtain anisotropic crack parameters;

[0015] Based on the logging data of the work area, elastic parameter inversion is performed on the corrected five-dimensional pre-stack gather to obtain the P-wave and S-wave velocity ratio of the work area.

[0016] The anisotropy parameter Δ is obtained based on the anisotropy parameter δ, the anisotropic crack parameter, and the P-wave / S-wave velocity ratio. N and Δ T .

[0017] A second aspect of the present invention provides an anisotropy parameter calculation apparatus for joint inversion of VVAZ and AVAZ, comprising:

[0018] The seismic data processing module is used to process seismic data to obtain five-dimensional pre-stack gathers;

[0019] The parameter δ calculation module is used to perform VVAZ inversion on the five-dimensional pre-stack gather to obtain the anisotropy parameter δ.

[0020] The time difference correction module is used to perform residual time difference correction on the five-dimensional pre-stack gather to obtain the corrected five-dimensional pre-stack gather;

[0021] The crack parameter module is used to perform AVAZ inversion on the corrected five-dimensional pre-stack gather to obtain anisotropic crack parameters;

[0022] The velocity ratio calculation module is used to perform elastic parameter inversion on the corrected five-dimensional pre-stack gather based on the well logging data of the work area to obtain the P-wave and S-wave velocity ratio of the work area.

[0023] Parameter Δ N and Δ T The module is used to calculate the anisotropy parameter Δ based on the anisotropy parameter δ, the anisotropic crack parameters, and the P-wave / S-wave velocity ratio. N and Δ T .

[0024] A third aspect of the present invention provides an electronic device, the electronic device comprising:

[0025] Memory, which stores executable instructions;

[0026] A processor that executes the executable instructions in the memory to implement the anisotropy parameter calculation method for the joint inversion of VVAZ and AVAZ as described in the first aspect.

[0027] A fourth aspect of the present invention provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the anisotropy parameter calculation method for joint inversion of VVAZ and AVAZ as described in the first aspect.

[0028] The beneficial effects of this invention include:

[0029] The proposed method for calculating anisotropy parameters using joint VVAZ and AVAZ inversion, based on the anisotropy results from VVAZ and AVAZ inversion, can realize the anisotropy parameter Δ of the Schobergn crack. N and Δ T Fast calculation based on Δ N and Δ TThe calculation results can be used to directly calculate the horizontal stress change rate or reservoir characteristic parameters such as the fluid identification factor containing fracture parameters, and then construct a refined description of five-dimensional seismic data for different types of reservoirs.

[0030] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0031] The above and other objects, features and advantages of the present invention will become more apparent from the more detailed description of exemplary embodiments of the invention in conjunction with the accompanying drawings.

[0032] Figure 1 This is a flowchart illustrating the anisotropy parameter calculation method for the joint inversion of VVAZ and AVAZ proposed in this invention.

[0033] Figure 2 This is a schematic diagram of a five-dimensional pre-stack gather (a five-dimensional spiral gather that preserves time difference) in a specific implementation of the anisotropy parameter calculation method for joint inversion of VVAZ and AVAZ proposed in this invention.

[0034] Figure 3 This is a schematic diagram of the VVAZ inversion result in a specific embodiment of the anisotropy parameter calculation method for joint inversion of VVAZ and AVAZ proposed in this invention.

[0035] Figure 4 This is a schematic diagram of the time difference correction result in a specific implementation of the anisotropy parameter calculation method for the joint inversion of VVAZ and AVAZ proposed in this invention.

[0036] Figure 5 This is a schematic diagram of the AVAZ inversion result in a specific embodiment of the anisotropy parameter calculation method for joint inversion of VVAZ and AVAZ proposed in this invention.

[0037] Figure 6 This is a schematic diagram of the P-wave and S-wave velocity ratio result g in a specific embodiment of the anisotropy parameter calculation method for the joint inversion of VVAZ and AVAZ proposed in this invention.

[0038] Figure 7 In a specific embodiment of the anisotropy parameter calculation method for the joint inversion of VVAZ and AVAZ proposed in this invention, the anisotropy parameter Δ N Diagram.

[0039] Figure 8 In a specific embodiment of the anisotropy parameter calculation method for joint inversion of VVAZ and AVAZ proposed in this invention, the anisotropy parameter Δ T Diagram. Detailed Implementation

[0040] Preferred embodiments of the invention will now be described in more detail. While preferred embodiments of the invention are described below, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein.

[0041] This invention provides a method for calculating anisotropy parameters in joint VVAZ and AVAZ inversion, such as... Figure 1 As shown, it includes:

[0042] Five-dimensional pre-stack gathers are obtained by processing seismic data;

[0043] VVAZ inversion was performed on the five-dimensional pre-stack gather to obtain the anisotropy parameter δ;

[0044] The corrected five-dimensional pre-stack gather is obtained by performing residual time difference correction on the five-dimensional pre-stack gather.

[0045] AVAZ inversion was performed on the corrected five-dimensional pre-stack gather to obtain anisotropic crack parameters;

[0046] Based on the logging data of the work area, elastic parameter inversion was performed on the corrected five-dimensional pre-stack gather to obtain the P-wave and S-wave velocity ratio of the work area.

[0047] The anisotropy parameter Δ is obtained based on the anisotropy parameter δ, the anisotropy crack parameter, and the P-wave / S-wave velocity ratio. N and Δ T .

[0048] In this invention, based on the anisotropy results obtained from VVAZ and AVAZ inversions, the Schobergn crack anisotropy parameter Δ can be realized. N and Δ T Fast calculation based on Δ N and Δ T The calculation results can be used to directly calculate the horizontal stress change rate or reservoir characteristic parameters such as the fluid identification factor containing fracture parameters, and then construct a refined description of five-dimensional seismic data for different types of reservoirs.

[0049] According to the present invention, the processing includes track editing, bandpass filtering, true amplitude recovery, static correction, velocity analysis, residual static correction, surface amplitude consistency compensation, pre-stack deconvolution, and dynamic correction.

[0050] The five-dimensional pre-stack gather retains anisotropic residual time difference information.

[0051] According to the present invention, the anisotropy parameter δ is obtained by performing VVAZ inversion on a five-dimensional pre-stack gather, including:

[0052] Calculate the static correction that varies over continuous time to estimate the remaining travel time;

[0053] For each analysis time, an elliptical residual NMO surface is fitted using the remaining travel time;

[0054] Based on the elliptic residual NMO surface, calculate the fast stacking rate and the slow stacking rate;

[0055] The anisotropy parameter δ is calculated using fast and slow stacking velocities.

[0056] The formula for calculating the anisotropy parameter δ is:

[0057]

[0058] Among them, V p_fast To achieve faster stacking speed, V p_slow This is a slow stacking speed.

[0059] According to the present invention, residual time difference correction for five-dimensional pre-stack gathers includes:

[0060] Residual time difference correction is performed based on five-dimensional pre-stack gathers to eliminate time difference and residual time difference factors that affect AVAZ inversion.

[0061] According to the present invention, the anisotropic crack parameters include anisotropic crack intensity and crack azimuth angle;

[0062] The formulas for calculating the strength and azimuth angle of anisotropic cracks are as follows:

[0063]

[0064] Where G1 is the isotropic gradient, G2 is the anisotropic gradient (i.e., the anisotropic crack intensity), φ0 is the crack azimuth angle, θ is the incident angle, and R is the amplitude value of the seismic data.

[0065] Based on the well logging data of the work area, elastic parameter inversion was performed on the calibrated five-dimensional pre-stack gathers to obtain the P-wave and S-wave velocity ratios of the work area, including:

[0066] Based on the well logging data of the work area, elastic parameter inversion was performed on the corrected five-dimensional pre-stack gather to obtain the P-wave velocity volume and S-wave velocity volume;

[0067] Based on the longitudinal wave velocity volume and the transverse wave velocity volume, the longitudinal wave velocity ratio of the work area is calculated;

[0068] The formula for calculating the P-wave / S-wave velocity ratio is:

[0069] g = α / β;

[0070] Where α is the longitudinal wave velocity volume, β is the transverse wave velocity volume, and g is the longitudinal wave velocity ratio to the transverse wave velocity.

[0071] According to the present invention, the anisotropy parameter Δ N and ΔT The calculation formula is:

[0072]

[0073] In this invention, the Thomsen anisotropy parameter δ can be obtained based on the fast and slow P-waves in VVAZ, and the anisotropic crack intensity G2 can be obtained using the AVAZ inversion technique based on the Ruger formula. However, the Schobergn anisotropy parameter Δ can be obtained directly by calculation. N and Δ T This is more difficult. This invention, based on the anisotropy results from VVAZ and AVAZ inversions, can achieve the anisotropy parameter Δ of the Schobergn crack by utilizing the relationship between different anisotropy parameters. N and Δ T Fast calculation based on Δ. N and Δ T The calculation results can be used to directly calculate the Differential Horizontal Stress Ratio (DHSR) or reservoir characteristic parameters such as the fluid identification factor containing fracture parameters, and construct refined five-dimensional seismic data description results for different types of reservoirs.

[0074] The present invention will be described in more detail below through embodiments.

[0075] Example 1:

[0076] like Figure 1 As shown, this embodiment proposes a method for calculating anisotropy parameters by joint inversion of VVAZ and AVAZ. This method performs comprehensive processing of seismic data for a "two-width and one-height" seismic acquisition system, and can obtain a five-dimensional seismic gather that retains anisotropic residual time difference information (XYZ in three-dimensional space plus azimuth and incidence angle).

[0077] VVAZ inversion was performed on the five-dimensional seismic gathers to obtain the anisotropy parameter δ;

[0078] Perform residual time difference correction on five-dimensional seismic gathers;

[0079] AVAZ inversion was performed on the time-difference corrected five-dimensional seismic gathers to obtain the anisotropic (fracture intensity) Bani.

[0080] Based on the well logging data of the work area, elastic parameter inversion was performed on the time-difference corrected five-dimensional seismic gather to obtain the longitudinal and transverse velocity volume g of the work area.

[0081] Δ N and Δ T Solving the two linear equations in two variables yields Δ. N and ΔT ;

[0082] The specific steps of this method are as follows:

[0083] ① After processing, a five-dimensional pre-stack set is generated;

[0084] Seismic data with "two widths and one height" undergoes seismic data processing, typically including, but not limited to, trace editing, bandpass filtering, true amplitude recovery, static correction, velocity analysis, residual static correction, surface amplitude consistency compensation, pre-stack deconvolution, and dynamic correction. The formation of a five-dimensional pre-stack gather requires omnidirectional migration imaging while preserving time differences, resulting in a five-dimensional spiral gather, such as... Figure 2 As shown;

[0085] ② Perform a five-dimensional VVAZ inversion to obtain the anisotropy parameter δ;

[0086] The main steps for AVAZ inversion using five-dimensional pre-stack gathers with time difference (five-dimensional spiral gathers) are as follows:

[0087] a. Calculate the static correction that varies over continuous time and estimate the remaining travel time;

[0088] b. For each analysis time, fit an elliptical residual NMO surface to the remaining travel time;

[0089] c. Therefore, calculate the elliptical superposition velocity and orientation: fast superposition velocity V p_fast Slow superposition speed V p_slow 1. Fast superposition velocity azimuth angle;

[0090] d. The Thomsen anisotropy parameter δ can be obtained using the superposition velocity of fast and slow waves. The specific calculation formula is as follows:

[0091]

[0092] In this embodiment, the VVAZ inversion results of the actual work area are as follows: Figure 3 As shown;

[0093] ③ Perform residual time difference correction on five-dimensional seismic gathers;

[0094] Residual time difference correction techniques are employed based on five-dimensional pre-stack gathers with time difference (i.e., five-dimensional spiral gathers) to eliminate time difference and residual time difference factors affecting AVAZ inversion. Residual time difference generally employs mutual coherence techniques; however, due to the abundance of patents related to this technique, it will not be elaborated upon here.

[0095] In this embodiment, the results before and after residual time difference correction for a certain line in the actual work area are as follows: Figure 4 As shown;

[0096] ④ Perform five-dimensional AVAZ inversion to obtain Bani;

[0097] After residual time difference correction, the five-dimensional pre-stack gather can be used to perform crack inversion to obtain the anisotropic intensity G2 and azimuth φ0. Alternatively, conventional AVAZ inversion can be used to obtain the crack intensity (i.e., anisotropic intensity) and crack azimuth. The specific formula is as follows:

[0098]

[0099] There are many articles and patents on obtaining crack parameters based on AVAZ inversion, so they will not be elaborated here. In this embodiment, the AVAZ inversion result of a certain line in the actual work area is shown in Bani as follows. Figure 5 As shown;

[0100] ⑤ Perform pre-stack elastic parameter inversion to obtain g;

[0101] For the five-dimensional pre-stack gather after residual time difference correction, if the azimuth angle is not considered, the five-dimensional pre-stack gather becomes a regular pre-stack angle gather without the azimuth angle.

[0102] By performing AVO inversion on the pre-stack angle gather, we can obtain the P-wave velocity volume α and the S-wave velocity volume β, and then obtain the P-wave / S-wave velocity ratio result volume g, i.e.:

[0103] g = α / β;

[0104] In this embodiment, the ratio of the P-wave and S-wave velocities retrieved from the actual work area is as follows: Figure 6 As shown;

[0105] ⑥ Solve the equation to obtain Δ N and Δ T :

[0106] Based on the relationship of anisotropy coefficients, the inversion results of VVAZ can also be expressed by Schobergn anisotropy parameters as equation (1):

[0107]

[0108] For the above equation, the result on the left side of the equation has been obtained through VVAZ inversion, and the P-wave / S-wave velocity ratio g can be obtained through conventional AVO inversion. Therefore, there are two unknowns Δ in equation (1). N and Δ T ;

[0109] The anisotropic gradient obtained by the Ruger formula inversion can be expressed by the Schobergn anisotropic parameters as equation (2):

[0110] G2=g(Δ T -(1-2g)Δ N );

[0111] In equation (2) above, the anisotropic gradient G2 has been obtained through AVAZ inversion, and the P-wave and S-wave velocity ratio g can be obtained through conventional AVO inversion. Therefore, there are two unknowns Δ in equation (2). N and Δ T ;

[0112] By combining equations (1) and (2), we can obtain Δ N and Δ T The exact solution is:

[0113]

[0114] Substituting the δ value obtained from the VVAZ inversion and the G2 value obtained from the AVAZ inversion into the above expression, we can obtain Δ. N and Δ T The accurate inversion results;

[0115] In this embodiment, the result of the accurate inversion is as follows: Figure 7 , 8 As shown.

[0116] This embodiment utilizes the solution relationship of the anisotropy parameters of VVAZ and AVAZ, the Thomsen anisotropy parameter δ, and the Schobergn anisotropy parameter Δ. N and Δ T The relationship between the anisotropic gradient Bani and the crack anisotropic parameter Δ is realized. N and Δ T A fast solution.

[0117] Example 2:

[0118] This embodiment provides a method for calculating anisotropy parameters through joint inversion of VVAZ and AVAZ, such as... Figure 1 As shown, it includes:

[0119] Five-dimensional pre-stack gathers are obtained by processing seismic data;

[0120] VVAZ inversion was performed on the five-dimensional pre-stack gather to obtain the anisotropy parameter δ;

[0121] The corrected five-dimensional pre-stack gather is obtained by performing residual time difference correction on the five-dimensional pre-stack gather.

[0122] AVAZ inversion was performed on the corrected five-dimensional pre-stack gather to obtain anisotropic crack parameters;

[0123] Based on the logging data of the work area, elastic parameter inversion was performed on the corrected five-dimensional pre-stack gather to obtain the P-wave and S-wave velocity ratio of the work area.

[0124] The anisotropy parameter Δ is obtained based on the anisotropy parameter δ, the anisotropy crack parameter, and the P-wave / S-wave velocity ratio. N and Δ T ;

[0125] In this embodiment, the processing includes trace editing, bandpass filtering, true amplitude recovery, static correction, velocity analysis, residual static correction, surface amplitude consistency compensation, pre-stack deconvolution, and dynamic correction.

[0126] Five-dimensional pre-stack gathers retain anisotropic residual time difference information;

[0127] In this embodiment, the anisotropy parameter δ obtained by performing VVAZ inversion on the five-dimensional pre-stack gather includes:

[0128] Calculate the static correction that varies over continuous time to estimate the remaining travel time;

[0129] For each analysis time, an elliptical residual NMO surface is fitted using the remaining travel time;

[0130] Based on the elliptic residual NMO surface, calculate the fast stacking rate and the slow stacking rate;

[0131] The anisotropy parameter δ is calculated using fast and slow stacking velocities.

[0132] The formula for calculating the anisotropy parameter δ is:

[0133]

[0134] Among them, V p_fast To achieve faster stacking speed, V p_slow Slow stacking speed;

[0135] In this embodiment, residual time difference correction for the five-dimensional pre-stack gather includes:

[0136] Residual time difference correction is carried out based on five-dimensional pre-stack gathers to eliminate time difference and residual time difference factors that affect AVAZ inversion;

[0137] In this embodiment, the anisotropic crack parameters include the anisotropic crack intensity and the crack azimuth angle;

[0138] The formulas for calculating the strength and azimuth angle of anisotropic cracks are as follows:

[0139]

[0140] Where G1 is the isotropic gradient, G2 is the anisotropic gradient (i.e., the anisotropic crack intensity), φ0 is the crack azimuth angle, θ is the incident angle, and R is the amplitude value of the seismic data.

[0141] In this embodiment, based on the well logging data of the work area, elastic parameter inversion is performed on the corrected five-dimensional pre-stack gather to obtain the P-wave and S-wave velocity ratios of the work area, including:

[0142] Based on the well logging data of the work area, elastic parameter inversion was performed on the corrected five-dimensional pre-stack gather to obtain the P-wave velocity volume and S-wave velocity volume;

[0143] Based on the longitudinal wave velocity volume and the transverse wave velocity volume, the longitudinal wave velocity ratio of the work area is calculated;

[0144] The formula for calculating the P-wave / S-wave velocity ratio is:

[0145] g = α / β;

[0146] Where α is the longitudinal wave velocity volume, β is the transverse wave velocity volume, and g is the longitudinal wave to transverse wave velocity ratio;

[0147] In this embodiment, the anisotropy parameter Δ N and Δ T The calculation formula is:

[0148]

[0149] Example 3:

[0150] This embodiment provides an anisotropy parameter calculation device for joint inversion of VVAZ and AVAZ, including:

[0151] The seismic data processing module is used to process seismic data to obtain five-dimensional pre-stack gathers;

[0152] The parameter δ calculation module is used to perform VVAZ inversion on five-dimensional pre-stack gathers to obtain the anisotropy parameter δ.

[0153] The time difference correction module is used to perform residual time difference correction on the five-dimensional pre-stack gather to obtain the corrected five-dimensional pre-stack gather;

[0154] The crack parameter module is used to perform AVAZ inversion on the corrected five-dimensional pre-stack gather to obtain anisotropic crack parameters;

[0155] The velocity ratio calculation module is used to perform elastic parameter inversion on the corrected five-dimensional pre-stack gather based on the logging data of the work area, and obtain the P-wave and S-wave velocity ratio of the work area.

[0156] Parameter Δ N and Δ T This module is used to determine the anisotropy parameter Δ based on the anisotropy parameter δ, the anisotropic crack parameters, and the P-wave / S-wave velocity ratio. N and Δ T ;

[0157] In this embodiment, the processing includes trace editing, bandpass filtering, true amplitude recovery, static correction, velocity analysis, residual static correction, surface amplitude consistency compensation, pre-stack deconvolution, and dynamic correction.

[0158] Five-dimensional pre-stack gathers retain anisotropic residual time difference information;

[0159] In this embodiment, the anisotropy parameter δ obtained by performing VVAZ inversion on the five-dimensional pre-stack gather includes:

[0160] Calculate the static correction that varies over continuous time to estimate the remaining travel time;

[0161] For each analysis time, an elliptical residual NMO surface is fitted using the remaining travel time;

[0162] Based on the elliptic residual NMO surface, calculate the fast stacking rate and the slow stacking rate;

[0163] The anisotropy parameter δ is calculated using fast and slow stacking velocities.

[0164] The formula for calculating the anisotropy parameter δ is:

[0165]

[0166] Among them, V p_fast To achieve faster stacking speed, V p_slow Slow stacking speed;

[0167] In this embodiment, residual time difference correction for the five-dimensional pre-stack gather includes:

[0168] Residual time difference correction is carried out based on five-dimensional pre-stack gathers to eliminate time difference and residual time difference factors that affect AVAZ inversion;

[0169] In this embodiment, the anisotropic crack parameters include the anisotropic crack intensity and the crack azimuth angle;

[0170] The formulas for calculating the strength and azimuth angle of anisotropic cracks are as follows:

[0171]

[0172] Where G1 is the isotropic gradient, G2 is the anisotropic gradient (i.e., the anisotropic crack intensity), φ0 is the crack azimuth angle, θ is the incident angle, and R is the amplitude value of the seismic data.

[0173] In this embodiment, based on the well logging data of the work area, elastic parameter inversion is performed on the corrected five-dimensional pre-stack gather to obtain the P-wave and S-wave velocity ratios of the work area, including:

[0174] Based on the well logging data of the work area, elastic parameter inversion was performed on the corrected five-dimensional pre-stack gather to obtain the P-wave velocity volume and S-wave velocity volume;

[0175] Based on the longitudinal wave velocity volume and the transverse wave velocity volume, the longitudinal wave velocity ratio of the work area is calculated;

[0176] The formula for calculating the P-wave / S-wave velocity ratio is:

[0177] g = α / β;

[0178] Where α is the longitudinal wave velocity volume, β is the transverse wave velocity volume, and g is the longitudinal wave to transverse wave velocity ratio;

[0179] In this embodiment, the anisotropy parameter Δ N and Δ T The calculation formula is:

[0180]

[0181] Example 4:

[0182] This invention provides an electronic device including a memory and a processor.

[0183] Memory, which stores executable instructions;

[0184] The processor executes executable instructions in memory to implement the anisotropic parameter calculation method for joint inversion of VVAZ and AVAZ.

[0185] This memory is used to store non-transitory computer-readable instructions. Specifically, the memory may include one or more computer program products, which may include various forms of computer-readable storage media, such as volatile memory and / or non-volatile memory. The volatile memory may, for example, include random access memory (RAM) and / or cache memory. The non-volatile memory may, for example, include read-only memory (ROM), hard disk, flash memory, etc.

[0186] The processor may be a central processing unit (CPU) or other form of processing unit with data processing capabilities and / or instruction execution capabilities, and may control other components in the electronic device to perform desired functions. In one embodiment of the invention, the processor is used to execute computer-readable instructions stored in the memory.

[0187] Those skilled in the art should understand that, in order to solve the technical problem of how to achieve a good user experience, this embodiment may also include well-known structures such as communication buses and interfaces, and these well-known structures should also be included within the protection scope of this invention.

[0188] For a detailed description of this embodiment, please refer to the corresponding descriptions in the foregoing embodiments, which will not be repeated here.

[0189] Example 5:

[0190] This invention provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements a method for calculating anisotropic parameters through joint inversion of VVAZ and AVAZ.

[0191] A computer-readable storage medium according to embodiments of the present invention stores non-transitory computer-readable instructions. When these non-transitory computer-readable instructions are executed by a processor, all or part of the steps of the methods described in the foregoing embodiments of the present invention are performed.

[0192] The aforementioned computer-readable storage media include, but are not limited to: optical storage media (e.g., CD-ROM and DVD), magneto-optical storage media (e.g., MO), magnetic storage media (e.g., magnetic tape or portable hard drive), media with built-in rewritable non-volatile memory (e.g., memory card), and media with built-in ROM (e.g., ROM cartridge).

[0193] The anisotropy parameter calculation method proposed in the embodiments of the present invention, based on the anisotropy results of VVAZ and AVAZ inversion, can realize the anisotropy parameter Δ of the Schobergn crack. N and Δ T Fast calculation based on Δ N and Δ T The calculation results can be used to directly calculate the horizontal stress change rate or reservoir characteristic parameters such as the fluid identification factor containing fracture parameters, and then construct a refined description of five-dimensional seismic data for different types of reservoirs.

[0194] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A method for calculating anisotropy parameters by VVAZ and AVAZ joint inversion, characterized in that, The method comprises the following steps: processing seismic data to obtain five-dimensional pre-stack gathers; performing VVAZ inversion on the five-dimensional pre-stack gathers to obtain anisotropy parameter δ; performing residual moveout correction on the five-dimensional pre-stack gathers to obtain corrected five-dimensional pre-stack gathers; performing AVAZ inversion on the corrected five-dimensional pre-stack gathers to obtain anisotropy fracture parameter; based on well logging data of the work area, performing elastic parameter inversion on the corrected five-dimensional pre-stack gathers to obtain P-S wave velocity ratio of the work area; determining an anisotropy parameter delta based on the anisotropy parameter delta, the anisotropy fracture parameter, and the P-wave to S-wave velocity ratio N and delta T .

2. The method of claim 1, wherein, the processing comprises trace editing, band-pass filtering, true amplitude recovery, static correction, velocity analysis, residual static correction, surface amplitude consistency compensation, pre-stack deconvolution and moveout correction; the five-dimensional pre-stack gathers retain anisotropy residual moveout information.

3. The method of claim 1, wherein, performing VVAZ inversion on the five-dimensional pre-stack gathers to obtain anisotropy parameter δ comprises: calculating continuously time-varying static correction amount and estimating residual travel time; for each analysis time, fitting an elliptical residual NMO surface using the residual travel time; based on the elliptical residual NMO surface, calculating fast stacking velocity and slow stacking velocity; calculating anisotropy parameter δ using the fast stacking velocity and the slow stacking velocity; the formula for calculating the anisotropy parameter δ is: where V p_fast is the fast stacking velocity, V p_slow is the slow stacking velocity.

4. The method of claim 3, wherein, performing residual moveout correction on the five-dimensional pre-stack gathers comprises: based on the five-dimensional pre-stack gathers, performing residual moveout correction to eliminate moveout and residual moveout factors affecting AVAZ inversion.

5. The method of claim 4, wherein, the anisotropy fracture parameter comprises anisotropy fracture strength and fracture azimuth angle; the formula for calculating the anisotropy fracture strength and the fracture azimuth angle is: wherein, G1 is isotropic gradient, G2 is anisotropic gradient, i.e. anisotropy fracture strength, φ0 is fracture azimuth angle, θ is incident angle, and R is amplitude value of seismic data.

6. The method of claim 5, wherein, based on well logging data of the work area, performing elastic parameter inversion on the corrected five-dimensional pre-stack gathers to obtain P-S wave velocity ratio of the work area comprises: based on well logging data of the work area, performing elastic parameter inversion on the corrected five-dimensional pre-stack gathers to obtain P-S wave velocity ratio of the work area comprises: based on the P-wave velocity body and the S-wave velocity body, calculating P-S wave velocity ratio of the work area; the formula for calculating the P-S wave velocity ratio is: g＝α / β； wherein, α is P-wave velocity body, β is S-wave velocity body, and g is P-S wave velocity ratio.

7. The method of claim 6, wherein, Anisotropy parameter Δ N and Δ T The calculation formula is:

8. An anisotropy parameter calculation device of VVAZ and AVAZ joint inversion, characterized in that, The method comprises the following steps: a seismic data processing module is configured to process seismic data to obtain five-dimensional pre-stack gathers; a parameter δ calculation module is configured to perform VVAZ inversion on the five-dimensional pre-stack gathers to obtain anisotropy parameter δ; a moveout correction module is configured to perform residual moveout correction on the five-dimensional pre-stack gathers to obtain corrected five-dimensional pre-stack gathers; a fracture parameter module is configured to perform AVAZ inversion on the corrected five-dimensional pre-stack gathers to obtain anisotropy fracture parameter; a velocity ratio calculation module is configured to perform elastic parameter inversion on the corrected five-dimensional pre-stack gathers based on well logging data of the work area to obtain P-S wave velocity ratio of the work area. Parameter Δ N and Δ T a module for calculating an anisotropy parameter Δ based on the anisotropy parameter δ, the anisotropy fracture parameter and the P-S wave velocity ratio N and Δ T .

9. An electronic device, comprising: The electronic device comprises: a memory storing executable instructions; a processor configured to execute the executable instructions in the memory to implement the anisotropy parameter calculation method of VVAZ and AVAZ joint inversion according to any one of claims 1-7.

10. A computer-readable storage medium, characterized in that, The computer readable storage medium stores a computer program, and the computer program is executed by the processor to implement the anisotropy parameter calculation method of the VVAZ and AVAZ joint inversion according to any one of claims 1-7.

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