Transverse isotropic hard formation horizontal shear wave velocity inversion method and device

Abstract

The invention relates to a transverse isotropic hard formation horizontal shear wave velocity inversion method and device. The method comprises the following steps: acquiring waveform data measured by a target interval array acoustic logging dipole mode; based on the waveform data, using a weighted spectrum coherence analysis method to calculate and obtain a bending wave actual measurement frequency dispersion curve; according to the bending wave actual measurement frequency dispersion curve, calculating to obtain bending wave time difference probability density; according to the bending wave time difference probability density, calculating to obtain a stratum vertical shear wave speed; establishing an objective function of transverse isotropic stratum horizontal shear wave velocity inversion based on a frequency dispersion equation of the transverse isotropic stratum and the stratum vertical shear wave velocity; and according to the objective function, inversion is carried out to obtain the stratum horizontal shear wave velocity. According to the method, the target function of horizontal shear wave velocity inversion is reduced from two dimensions to one dimension, and the stability and efficiency of inversion are remarkably improved.

Description

Technical Field

[0001] The invention relates to the field of oil and gas exploration, and in particular to a method and a device for inverting horizontal shear wave velocity of a transversely isotropic hard stratum. Background Art

[0002] With the continuous deepening of oil and gas exploration and development, unconventional reservoirs have become an important strategic successor area. Unconventional reservoirs are fine-grained deposits with well-developed laminations and foliations. The strata have obvious transverse isotropy characteristics, that is, the elasticity of the formation parameters shows obvious differences in the horizontal and vertical directions. When evaluating the rock mechanical parameters and ground stresses of this type of reservoir, an anisotropic model is required, and the key is to accurately determine the horizontal shear wave velocity of the formation. In soft formations, the method of inverting the horizontal shear wave velocity of the formation using the monopole Stoneley wave of array acoustic logging is relatively mature. In hard formations, dipole bending waves are currently mainly used to invert the horizontal shear wave velocity, and the inversion method is two-dimensional. Summary of the invention

[0003] In order to obtain a more stable and efficient inversion result of horizontal shear wave velocity in a transversely isotropic hard formation, an embodiment of the present invention provides a method and device for inversion of horizontal shear wave velocity in a transversely isotropic hard formation.

[0004] In a first aspect, an embodiment of the present application provides a method for inverting horizontal shear wave velocity in a transversely isotropic hard formation, the method comprising:

[0005] Acquire waveform data of dipole mode measurement of array acoustic logging in the target layer;

[0006] Based on the waveform data, a weighted spectrum coherence analysis method is used to calculate a measured dispersion curve of the bending wave;

[0007] According to the measured dispersion curve of the bending wave, the probability density of the bending wave time difference is calculated;

[0008] The vertical shear wave velocity of the formation is calculated according to the bending wave time difference probability density;

[0009] Establishing an objective function for inversion of horizontal shear wave velocity of a transversely isotropic formation based on a dispersion equation of the transversely isotropic formation and the vertical shear wave velocity of the formation;

[0010] According to the objective function, the horizontal shear wave velocity of the formation is obtained by inversion.

[0011] In one or some optional implementations of the embodiments of the present application, the objective function of inversion of horizontal shear wave velocity of a transversely isotropic formation is established based on the dispersion equation of the transversely isotropic formation and the vertical shear wave velocity of the formation, including:

[0012] Obtain formation density and formation vertical P-wave velocity;

[0013] Substituting the formation density, the formation vertical P-wave velocity and the formation vertical S-wave velocity into the dispersion equation to obtain a bending wave theoretical dispersion curve;

[0014] Based on the measured flexural wave dispersion curve and the theoretical flexural wave dispersion curve, the objective function of the horizontal shear wave velocity inversion of the transversely isotropic formation is established, as shown in Formula 1:

[0015]

[0016] In the formula, E(V SH ) is the horizontal shear wave velocity V SH The calculated inversion objective function; V(ω) is the measured dispersion curve of the bending wave; V T (ω,V SH ) is the horizontal shear wave velocity V SH The calculated theoretical dispersion curve of the bending wave; Ω is the processing frequency band of the inversion.

[0017] In one or some optional implementations of the embodiments of the present application,

[0018] Substituting the formation density, the formation vertical P-wave velocity and the formation vertical S-wave velocity into the dispersion equation to solve and obtain a bending wave theoretical dispersion curve includes:

[0019] Substituting the formation density, the formation vertical P-wave velocity and the formation vertical S-wave velocity into the following dispersion equation Formula 2, solving the wave number at different angular frequencies, the bending wave theoretical dispersion curve is obtained:

[0020] D(n,k,ω,C VTI )=0 Formula 2;

[0021] Where n is the source order, k is the wave number, ω is the angular frequency, C VTI is the stiffness matrix of the transversely isotropic formation, as shown in the following formula 3;

[0022]

[0023] In the formula, C 11 , C 13 , C 33 , C 44 , C 66 is the stiffness matrix parameter of the transversely isotropic formation, Where ρ is the formation density, V P0 is the vertical P-wave velocity of the formation, V SV is the vertical shear wave velocity of the formation, V SHis the horizontal shear wave velocity of the formation; based on the Annie approximation model, C 13 and C 13 It can be calculated by the following formula 4:

[0024]

[0025] In one or some optional implementations of the embodiments of the present application, the method of calculating the measured dispersion curve of the bending wave based on the waveform data using a weighted spectrum coherence analysis method includes:

[0026] Substitute the waveform data into the following weighted spectrum coherence analysis formula 5 to calculate the spectrum coherence function of the waveform data within the first preset spectrum range and the first preset time difference range:

[0027]

[0028] Where ρ(ω,s) is the spectral coherence function at the specified frequency and time difference, X n (ω) is the frequency spectrum of the waveform data, is the conjugate spectrum of the waveform data, N is the number of receivers of the array acoustic logging instrument, s is the time difference, ω is the angular frequency, and d is the distance between two adjacent receivers;

[0029] The maximum value of the coherence function of the spectrum analyzer at each frequency is extracted within the first preset time difference range as the bending wave time difference of the frequency to obtain the bending wave measured dispersion curve.

[0030] In one or some optional implementations of the embodiments of the present application, before calculating the measured dispersion curve of the bending wave based on the waveform data using a weighted spectrum coherence analysis method, the method further includes:

[0031] The waveform data is preprocessed; wherein the preprocessing includes waveform start time correction, waveform gain removal and digital filtering operations.

[0032] In one or some optional implementations of the embodiment of the present application, the calculating the bending wave time difference probability density according to the measured bending wave dispersion curve comprises:

[0033] According to the measured bending wave dispersion curve, the bending wave time difference probability density is calculated in the second preset frequency range based on the following formula 6:

[0034]

[0035] Where SPD(s) is the probability density of the corresponding time difference, ω H is the right boundary of the second preset frequency range, ω L is the left boundary of the second preset frequency range, sd (ω) is the average value of the bending wave time difference within the second preset frequency range; σ s is the variance of the bending wave time difference within the second preset frequency range, and dω is the frequency sampling interval of the measured bending wave dispersion curve.

[0036] In one or some optional implementations of the embodiment of the present application, the vertical shear wave velocity of the formation is calculated according to the bending wave time difference probability density, including:

[0037] Based on the following adaptation function formula 7 and the bending wave time difference probability density, the solution of the fitting parameters is obtained:

[0038] F(s)=A(s-s0)βe -α(s-s0) ,s≥s0 Formula 7;

[0039] In the formula, A, α, β, s0 ​​are all fitting parameters;

[0040] According to the solution of the fitting parameters, the vertical shear wave time difference of the formation is obtained;

[0041] The vertical shear wave velocity of the formation is calculated according to the vertical shear wave time difference of the formation.

[0042] In a second aspect, an embodiment of the present application provides a device for inverting horizontal shear wave velocity in a transversely isotropic hard formation, the device comprising:

[0043] The first acquisition module is used to acquire waveform data measured by dipole mode of array acoustic logging in the target layer;

[0044] A first calculation module is used to calculate and obtain a measured dispersion curve of a bending wave based on the waveform data by using a weighted spectrum coherence analysis method;

[0045] A second calculation module is used to calculate the bending wave time difference probability density according to the measured bending wave dispersion curve;

[0046] A third calculation module is used to calculate the vertical shear wave velocity of the formation according to the bending wave time difference probability density;

[0047] A first establishment module is used to establish an objective function for inversion of horizontal shear wave velocity of a transversely isotropic formation based on a dispersion equation of the transversely isotropic formation and the vertical shear wave velocity of the formation;

[0048] The first inversion module is used to invert and obtain the horizontal shear wave velocity of the formation according to the objective function.

[0049] In a third aspect, an embodiment of the present application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the horizontal shear wave velocity inversion method for a transversely isotropic hard formation as described above.

[0050] In a fourth aspect, an embodiment of the present application provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the horizontal shear wave velocity inversion method for a transversely isotropic hard formation as described above is implemented.

[0051] In a fifth aspect, an embodiment of the present application provides a computer program product comprising instructions, which, when executed on a computer device, enables the computer device to execute the horizontal shear wave velocity inversion method for a transversely isotropic hard formation as described above.

[0052] In a sixth aspect, an embodiment of the present application provides a chip, the chip including a processor and a communication interface, the communication interface and the processor are coupled, and the processor is used to run a computer program or instruction to implement the horizontal shear wave velocity inversion method of a transversely isotropic hard formation as described above.

[0053] The beneficial effects of the above technical solution provided by the embodiment of the present invention include at least:

[0054] The method for inverting the horizontal shear wave velocity of a transversely isotropic hard formation provided in the embodiment of the present application obtains flexural wave waveform data through the dipole measurement mode of array acoustic logging, uses weighted spectral coherence analysis technology to accurately calculate the vertical shear wave velocity of the formation, establishes an objective function for inverting the horizontal shear wave velocity of the transversely isotropic formation based on the rigidity matrix and dispersion equation of the transversely isotropic formation and the vertical shear wave velocity of the formation, and uses a nonlinear fast global optimization algorithm to invert the horizontal shear wave velocity of the formation. This method reduces the current inversion method for horizontal shear wave velocity using the flexural wave dispersion characteristics from two dimensions to one dimension. While ensuring accuracy, it can not only improve the stability of the inversion result, but also greatly improve the calculation efficiency, which is convenient for promotion and application.

[0055] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 It is a flow chart of a method for inverting horizontal shear wave velocity of a transversely isotropic hard formation provided in an embodiment of the present application;

[0057] Figure 2 It is a schematic diagram of the inversion results of the horizontal shear wave velocity of the formation provided by the embodiment of the present application;

[0058] Figure 3 It is a schematic diagram of the structure of a device for inverting horizontal shear wave velocity in a transversely isotropic hard formation provided in an embodiment of the present application. DETAILED DESCRIPTION

[0059] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application may also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present application.

[0060] It should be understood that when used in the present specification and the appended claims, the term "comprising" indicates the presence of described features, wholes, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or clusters thereof.

[0061] It should also be understood that the term “and / or” used in the specification and appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0062] As used in the specification and appended claims of this application, the term "if" can be interpreted as "when" or "uponce" or "in response to determining" or "in response to detecting", depending on the context. Similarly, the phrase "if it is determined" or "if [described condition or event] is detected" can be interpreted as meaning "uponce it is determined" or "in response to determining" or "uponce [described condition or event] is detected" or "in response to detecting [described condition or event]", depending on the context.

[0063] In addition, in the description of the present application specification and the appended claims, the terms "first", "second", "third", etc. are only used to distinguish the descriptions and cannot be understood as indicating or implying relative importance.

[0064] References to "one embodiment" or "some embodiments" etc. described in the specification of this application mean that one or more embodiments of the present application include specific features, structures or characteristics described in conjunction with the embodiment. Therefore, the statements "in one embodiment", "in some embodiments", "in some other embodiments", "in some other embodiments", etc. that appear in different places in this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized in other ways.

[0065] It should be understood that the size of the serial numbers of the steps in the following embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0066] In order to illustrate the technical solution of the present application, a specific embodiment is provided below for illustration.

[0067] The inventors have found that in the prior art for obtaining the horizontal shear wave velocity of hard formations, dipole bending waves are currently mainly used to invert the horizontal shear wave velocity, and the inversion method is two-dimensional. The actual processing efficiency of the two-dimensional inversion algorithm is low, and the inversion result is easily unstable, which will affect the calculation accuracy of the horizontal shear wave velocity in the actual hard formation. Therefore, there is an urgent need for a method for inverting the horizontal shear wave velocity of a transversely isotropic hard formation to meet the needs of oil and gas exploration and development. Based on this, the inventors have made the present invention after further research, providing a method and device for inverting the horizontal shear wave velocity of a transversely isotropic hard formation.

[0068] Embodiment 1

[0069] See also Figure 1 , is a method for inverting the horizontal shear wave velocity of a transversely isotropic hard formation provided in Example 1 of the present application, referring to Figure 1 As shown, the method includes:

[0070] S101: Acquire waveform data of array acoustic logging dipole mode measurement in the target layer.

[0071] In an embodiment of the present application, obtaining waveform data of dipole measurement of the target layer segment in the above step S101 refers to using a multipole array acoustic logging instrument to measure a specific target layer segment in the well, and collecting four-component waveform data in the dipole measurement mode. First, it is necessary to prepare a multipole array acoustic logging instrument. The array acoustic logging instrument includes multiple receivers. In the well, the instrument is lowered to the target layer segment to be measured; then, the dipole measurement mode and other parameters are selected, such as sampling rate, observation time window, etc.; in the dipole measurement mode, the instrument will simultaneously record waveform data from different components, including amplitude, frequency, phase and other information. In the present application, the four-component waveform data obtained include XX direction component, XY direction component, YY direction component, and YX direction component.

[0072] In the embodiment of the present application, the waveform data is also preprocessed, and the preprocessing includes waveform start time correction, waveform gain reduction and digital filtering operations. The waveform start time correction corrects the waveform data of different components to a unified time base, thereby ensuring that the waveform data of different components are consistent in time; the waveform gain reduction adjusts the amplitude of the waveform to make the amplitude of the signal and noise more balanced, removes interference or noise in the data, so as to improve the clarity of the signal and better reflect the characteristics of the underground medium; the digital filter selectively removes or retains the signal within a specific frequency range, removes unnecessary frequency components, and retains the frequency information of interest to obtain cleaner data.

[0073] S102: Based on the waveform data, a weighted spectrum coherence analysis method is used to calculate and obtain a measured dispersion curve of the bending wave.

[0074] In the embodiment of the present application, in the above step S102, based on the waveform data, a weighted spectrum coherence analysis method is used to calculate the measured dispersion curve of the bending wave.

[0075] The four-component waveform data preprocessed in step S101 is subjected to frequency analysis, and Fourier transform or other spectrum analysis methods can be used to obtain spectrum, amplitude and phase information at different frequencies. Calculation is performed for each frequency, and the spectrum data is substituted into the following weighted spectrum coherence function, as shown in the following formula 5, to calculate the weighted spectrum coherence function value:

[0076]

[0077] Where ρ(ω,s) is the spectral coherence function at the specified frequency and time difference, X n (ω) is the frequency spectrum of the waveform data, is the conjugate spectrum of the waveform data, N is the number of receivers of the array acoustic logging instrument, s is the time difference, ω is the angular frequency, and d is the distance between two adjacent receivers.

[0078] The maximum value of the weighted spectral coherence function at each frequency point in the bending wave time difference range is extracted as the bending wave time difference at the frequency. The obtained bending wave time difference versus frequency is plotted as a measured dispersion curve to obtain a bending wave measured dispersion curve.

[0079] S103: Calculate the bending wave time difference probability density according to the measured bending wave dispersion curve.

[0080] In the embodiment of the present application, in the above step S103, according to the measured dispersion curve of the bending wave obtained in step S102, the bending wave time difference probability density is calculated based on the following formula 3 within a preset frequency range at a certain interval (frequency range):

[0081]

[0082] Where SPD(s) is the probability density of the corresponding time difference, ω H is the right boundary of the preset frequency range, ω L is the left boundary of the preset frequency range, s d (ω) is the average value of the bending wave time difference within the second preset frequency range; σ s is the variance of the bending wave time difference within the second preset frequency range, and dω is the frequency sampling interval of the measured bending wave dispersion curve.

[0083] S104: Calculate the vertical shear wave velocity of the formation according to the bending wave time difference probability density.

[0084] In the embodiment of the present application, in the above step S104, the vertical shear wave velocity of the formation is calculated according to the bending wave time difference probability density, including: establishing an adaptation function that needs to be able to fit the bending wave time difference probability density to a certain extent. Based on the following adaptation function formula 7 and the bending wave time difference probability density, the solution of the fitting parameter is obtained:

[0085] F(s)=A(s-s0)βe -α(s-s0) ,s≥s0 Formula 7;

[0086] Where A, α, β, and s0 are all fitting parameters. By fitting the bending wave time difference probability density curve and the adaptation function, the solutions of the above four fitting parameters are obtained. According to the adaptation function parameters, the vertical shear wave time difference of the formation can be calculated, as shown in Formula 8:

[0087]

[0088] The vertical shear wave velocity of the formation can be calculated based on the conversion relationship between the vertical shear wave time difference and the velocity, as shown in Formula 9:

[0089] V SV =1 / s Formula 9;

[0090] S105: Establishing an objective function for inversion of horizontal shear wave velocity of the transversely isotropic formation based on the dispersion equation of the transversely isotropic formation and the vertical shear wave velocity of the formation.

[0091] S106: According to the objective function, the horizontal shear wave velocity of the formation is obtained by inversion.

[0092] In the embodiment of the present application, in the above step S105, the objective function of the inversion of the horizontal shear wave velocity of the transversely isotropic formation is established based on the dispersion equation of the transversely isotropic formation and the vertical shear wave velocity of the formation, including:

[0093] Obtain formation density and formation vertical P-wave velocity;

[0094] Substituting the formation density, the formation vertical P-wave velocity and the formation vertical S-wave velocity into the following dispersion equation Formula 2, solving the wave number at different angular frequencies, the bending wave theoretical dispersion curve is obtained:

[0095] D(n,k,ω,C VTI )=0 Formula 2;

[0096] Where n is the source order, k is the wave number, ω is the angular frequency, C VTI is the stiffness matrix of the transversely isotropic formation, as shown in the following formula 3;

[0097]

[0098] In the formula, C 11 , C 13 , C 33 , C 44 , C 66 is the stiffness matrix parameter of the transversely isotropic formation, Where ρ is the formation density, V P0 is the vertical P-wave velocity of the formation, V SV is the vertical shear wave velocity of the formation, V SH is the horizontal shear wave velocity of the formation; based on the Annie approximation model, C 13 and C 13 It can be calculated by the following formula 4:

[0099]

[0100] Based on the measured flexural wave dispersion curve and the theoretical flexural wave dispersion curve, the objective function of the horizontal shear wave velocity inversion of the transversely isotropic formation is established, as shown in Formula 1:

[0101]

[0102] In the formula, E(V SH ) is the horizontal shear wave velocity V SH The calculated inversion objective function; V(ω) is the measured dispersion curve of the bending wave; V T (ω,V SH ) is the horizontal shear wave velocity V SH The calculated theoretical dispersion curve of the bending wave; Ω is the processing frequency band of the inversion.

[0103] In a specific embodiment, the stiffness matrix of the transversely isotropic formation can be calculated using the formation density, the formation vertical P-wave velocity, the formation vertical S-wave velocity, and the formation horizontal S-wave velocity. The stiffness matrix is ​​directly obtained according to the current formation properties. The specific calculation formula is shown in Formula 3. When calculating based on the transversely isotropic model, it is necessary to determine C 11 , C 13 , C 33 , C 44 , C 66 Five elastic parameters, among which C 33 , C 44 , C 66 It can be calculated based on the formation density, the vertical longitudinal wave velocity, the vertical shear wave velocity and the horizontal shear wave velocity. 11 , C 13 The above parameters cannot be directly obtained and need to be estimated through a prediction model. In this scheme, the Annie approximation model is used to obtain C 11 With C 13 Using C 33 , C 44 , C 66 The calculation expression of . The obtained rigid matrix parameters of the transversely isotropic formation, the borehole fluid density, the fluid velocity and other related parameters are introduced into the dispersion equation of the propagation of multipole acoustic waves in the transversely isotropic formation, as shown in Formula 2. The dispersion equation is used to solve the wave number at different angular frequencies, and the theoretical dispersion curve containing the variable transversely isotropic formation shear wave velocity is obtained.

[0104] The objective function of horizontal shear wave velocity inversion of transversely isotropic formations is established using the measured flexural wave dispersion curve obtained in step S102 and the theoretical dispersion curve, as shown in Formula 1. The objective function measures the residual between the theoretical dispersion curve and the measured dispersion curve during the inversion calculation process.

[0105] In the embodiment of the present application, the objective function of the horizontal shear wave velocity inversion of the transversely isotropic formation is obtained. When the objective function is minimum, the corresponding horizontal shear wave velocity of the formation is the target horizontal shear wave velocity obtained by inversion. In a given horizontal shear wave velocity value interval, a nonlinear fast global optimization algorithm is used to find the inversion result of the horizontal shear wave velocity and the optimal solution. The nonlinear fast global optimization algorithm used is not limited. In a specific embodiment, the least squares method is used to solve the horizontal shear wave velocity corresponding to the minimum value of the objective function as the formation.

[0106] The results of the inversion of the horizontal shear wave velocity of the formation are shown in the figure below: Figure 2As shown, the lithology curves, porosity curves, and resistivity curves in the first to third columns are all data that can be directly measured by well logging. In the fourth formation shear wave velocity, DTSV is the vertical shear wave velocity of the formation obtained in step S104, and DTSH is the horizontal shear wave velocity of the formation obtained in step S106. The fifth shear wave anisotropy is the difference between DTSH and DTSV. This scheme can obtain a stable horizontal shear wave velocity inversion method, while ensuring accuracy, improving the stability of the inversion results. Vertical shear wave velocity and horizontal shear wave velocity are important basic data for geological exploration. Stable inversion results can help build a more detailed underground model.

[0107] Embodiment 2

[0108] Based on the same inventive concept, the present application also provides a device for inverting the horizontal shear wave velocity of a transversely isotropic hard formation. Figure 3 As shown, the device comprises:

[0109] The first acquisition module 101 is used to acquire waveform data measured by dipole mode of array acoustic logging in the target layer;

[0110] A first calculation module 102 is used to calculate and obtain a measured dispersion curve of a bending wave based on the waveform data using a weighted spectrum coherence analysis method;

[0111] A second calculation module 103 is used to calculate the bending wave time difference probability density according to the measured bending wave dispersion curve;

[0112] A third calculation module 104 is used to calculate the vertical shear wave velocity of the formation according to the bending wave time difference probability density;

[0113] The first establishing module 105 is used to establish an objective function for inversion of horizontal shear wave velocity of a transversely isotropic formation based on a dispersion equation of the transversely isotropic formation and the vertical shear wave velocity of the formation;

[0114] The first inversion module 106 is used to invert and obtain the horizontal shear wave velocity of the formation according to the objective function.

[0115] Embodiment 3

[0116] Based on the same inventive concept, an embodiment of the present application also provides a computer-readable storage medium on which a computer program is stored. When the program is executed by a processor, the method for inverting horizontal shear wave velocity of a transversely isotropic hard formation as described in the above-mentioned embodiment 1 is implemented.

[0117] Embodiment 4

[0118] Based on the same inventive concept, an embodiment of the present application also provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the method for inversion of horizontal shear wave velocity of a transversely isotropic hard formation as described in the above-mentioned embodiment 1 is implemented.

[0119] Embodiment 5

[0120] Based on the same inventive concept, an embodiment of the present application also provides a computer program product containing instructions. When the computer program product is run on a computer device, the computer device executes the method for horizontal shear wave velocity inversion of a transversely isotropic hard formation as described in the above-mentioned embodiment 1.

[0121] Embodiment 6

[0122] Based on the same inventive concept, an embodiment of the present application also provides a chip, the chip includes a processor and a communication interface, the communication interface and the processor are coupled, and the processor is used to run a computer program or instruction to implement the horizontal shear wave velocity inversion method of transversely isotropic hard formations as described in the above-mentioned embodiment one.

[0123] The technicians in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example. In practical applications, the above-mentioned function allocation can be completed by different functional units and modules as needed, that is, the internal structure of the device is divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated into a processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned device can refer to the corresponding process in the above-mentioned method embodiment, which will not be repeated here. If the integrated unit 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 such understanding, the present application implements all or part of the processes in the above-mentioned embodiment method, which can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a computer-readable storage medium, and the computer program can implement the steps of the above-mentioned method embodiment when executed by the processor. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may at least include: any entity or device capable of carrying computer program code, recording medium, computer memory, read-only memory (ROM), random access memory (RAM), electric carrier signal, telecommunication signal and software distribution medium. For example, a USB flash drive, a mobile hard disk, a magnetic disk or an optical disk. In some jurisdictions, according to legislation and patent practice, computer-readable media cannot be electric carrier signals and telecommunication signals.

[0124] The present application implements all or part of the processes in the above-mentioned embodiment method, and may also be completed through a computer program product. When the computer program product runs on a computer device, the computer device can implement the steps in the above-mentioned method embodiment when executing the computer program product.

[0125] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0126] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0127] In the embodiments provided in the present application, it should be understood that the disclosed devices / computer equipment and methods can be implemented in other ways. For example, the device / computer equipment embodiments described above are only schematic. For example, the division of modules or units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0128] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0129] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A method for inverting horizontal shear wave velocity in a transversely isotropic hard formation, characterized in that: include: Acquire waveform data of dipole mode measurement of array acoustic logging in the target layer; Based on the waveform data, a weighted spectrum coherence analysis method is used to calculate a measured dispersion curve of the bending wave; According to the measured dispersion curve of the bending wave, the probability density of the bending wave time difference is calculated; The vertical shear wave velocity of the formation is calculated according to the bending wave time difference probability density; Establishing an objective function for inversion of horizontal shear wave velocity of a transversely isotropic formation based on a dispersion equation of the transversely isotropic formation and the vertical shear wave velocity of the formation; According to the objective function, the horizontal shear wave velocity of the formation is obtained by inversion.

2. The method according to claim 1, characterized in that The objective function of establishing the horizontal shear wave velocity inversion of the transversely isotropic formation based on the dispersion equation of the transversely isotropic formation and the vertical shear wave velocity of the formation includes: Obtain formation density and formation vertical P-wave velocity; Substituting the formation density, the formation vertical P-wave velocity and the formation vertical S-wave velocity into the dispersion equation to obtain a bending wave theoretical dispersion curve; Based on the measured flexural wave dispersion curve and the theoretical flexural wave dispersion curve, the objective function of the horizontal shear wave velocity inversion of the transversely isotropic formation is established, as shown in Formula 1: In the formula, E(V SH ) is the horizontal shear wave velocity V SH The calculated inversion objective function; V(ω) is the measured dispersion curve of the bending wave; V T (ω,V SH ) is the horizontal shear wave velocity V SH The calculated theoretical dispersion curve of the bending wave; Ω is the processing frequency band of the inversion.

3. The method according to claim 2, characterized in that Substituting the formation density, the formation vertical P-wave velocity and the formation vertical S-wave velocity into the dispersion equation to solve and obtain a bending wave theoretical dispersion curve includes: Substituting the formation density, the formation vertical P-wave velocity and the formation vertical S-wave velocity into the following dispersion equation Formula 2, solving the wave number at different angular frequencies, the bending wave theoretical dispersion curve is obtained: D(n,k,ω,C VTI ) = 0 Equation 2; Where n is the source order, k is the wave number, ω is the angular frequency, C VTI is the stiffness matrix of the transversely isotropic formation, as shown in the following formula 3; In the formula, C 11 , C 13 , C 33 , C 44 , C 66 is the stiffness matrix parameter of the transversely isotropic formation, Where ρ is the formation density, V P0 is the vertical P-wave velocity of the formation, V SV is the vertical shear wave velocity of the formation, V SH is the horizontal shear wave velocity of the formation; based on the Annie approximation model, C 13 and C 13 It can be calculated by the following formula 4:

4. The method according to claim 1, characterized in that The method of calculating the measured dispersion curve of the bending wave based on the waveform data using a weighted spectrum coherence analysis method comprises: Substitute the waveform data into the following weighted spectrum coherence analysis formula 5 to calculate the spectrum coherence function of the waveform data within the first preset spectrum range and the first preset time difference range: Where ρ(ω,s) is the spectral coherence function at the specified frequency and time difference, X n (ω) is the frequency spectrum of the waveform data, is the conjugate spectrum of the waveform data, N is the number of receivers of the array acoustic logging instrument, s is the time difference, ω is the angular frequency, and d is the distance between two adjacent receivers; The maximum value of the coherence function of the spectrum analyzer at each frequency is extracted within the first preset time difference range as the bending wave time difference of the frequency to obtain the bending wave measured dispersion curve.

5. The method according to claim 1, characterized in that Before calculating the measured dispersion curve of the bending wave based on the waveform data using a weighted spectrum coherence analysis method, the method further includes: The waveform data is preprocessed; wherein the preprocessing includes waveform start time correction, waveform gain removal and digital filtering operations.

6. The method according to claim 1, characterized in that The step of calculating the bending wave time difference probability density according to the measured bending wave dispersion curve comprises: According to the measured bending wave dispersion curve, the bending wave time difference probability density is calculated in the second preset frequency range based on the following formula 6: Where SPD(s) is the probability density of the corresponding time difference, ω H is the right boundary of the second preset frequency range, ω L is the left boundary of the second preset frequency range, s d (ω) is the average value of the bending wave time difference within the second preset frequency range; σ s is the variance of the bending wave time difference within the second preset frequency range, and dω is the frequency sampling interval of the measured bending wave dispersion curve.

7. The method according to claim 1, characterized in that The step of calculating the vertical shear wave velocity of the formation according to the bending wave time difference probability density comprises: Based on the following adaptation function formula 7 and the bending wave time difference probability density, the solution of the fitting parameters is obtained: F(s)=A(s-s0)βe -α(s-s0) ,s≥s0 Formula 7; In the formula, A, α, β, s0 ​​are all fitting parameters; According to the solution of the fitting parameters, the vertical shear wave time difference of the formation is obtained; The vertical shear wave velocity of the formation is calculated according to the vertical shear wave time difference of the formation.

8. A device for inverting horizontal shear wave velocity in a transversely isotropic hard formation, characterized in that: include: The first acquisition module is used to acquire waveform data measured by dipole mode of array acoustic logging in the target layer; A first calculation module is used to calculate and obtain a measured dispersion curve of a bending wave based on the waveform data by using a weighted spectrum coherence analysis method; A second calculation module is used to calculate the bending wave time difference probability density according to the measured bending wave dispersion curve; A third calculation module is used to calculate the vertical shear wave velocity of the formation according to the bending wave time difference probability density; A first establishment module is used to establish an objective function for inversion of horizontal shear wave velocity of a transversely isotropic formation based on a dispersion equation of the transversely isotropic formation and the vertical shear wave velocity of the formation; The first inversion module is used to invert and obtain the horizontal shear wave velocity of the formation according to the objective function.

9. A computer-readable storage medium storing instructions, which, when executed on a terminal, enable the terminal to execute the method for inverting horizontal shear wave velocity of a transversely isotropic hard formation as described in any one of claims 1 to 7.

10. A computer device, characterized in that: The method comprises a memory, a processor and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the method for inversion of horizontal shear wave velocity of a transversely isotropic hard formation as described in any one of claims 1 to 7 is implemented.

11. A computer program product comprising instructions, which, when executed on a computer device, enables the computer device to execute the method for inversion of horizontal shear wave velocity in a transversely isotropic hard formation as claimed in any one of claims 1 to 7.

12. A chip, comprising a processor and a communication interface, wherein the communication interface and the processor are coupled, and the processor is used to run a computer program or instruction to implement the method for horizontal shear wave velocity inversion of a transversely isotropic hard formation as described in any one of claims 1 to 7.

Images