Anisotropy parameter inversion method, device, equipment and storage medium

Abstract

The application provides a kind of anisotropy parameter inversion method, device, equipment and storage medium, comprising: establishing the anisotropy petrophysical model of shale of multi-mineral mixture, complex pore combination, containing anisotropic clay;Rock physical test is carried out, and petrophysical test data and rock sample anisotropy parameter are acquired;In combination with petrophysical test data, petrophysical analysis is carried out, and the petrophysical model and related parameters suitable for shale rock structure and theoretical model physical mechanism are obtained;The anisotropy petrophysical model of shale based on petrophysical analysis is used to carry out the anisotropy petrophysical model of shale based on petrophysical analysis to the pore aspect ratio and clay orientation degree inversion of logging data;The parameters obtained by inversion are substituted into the anisotropy petrophysical model of shale, and the anisotropy parameter is solved in combination with the definition of Thomsen anisotropy parameter.The inversion result in the application has reasonable theoretical support and actual petrophysical significance.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of geophysical exploration, in particular to an anisotropy parameter inversion method, device, equipment and storage medium. BACKGROUND

[0002] Due to the internal clay, organic matter, directional arrangement of microcracks and complex mineral components of shale oil and gas reservoirs, the elastic properties of shale show strong anisotropy, and there are significant response characteristics on seismic and logging. The research on the relationship between the internal structural properties of shale reservoirs and anisotropy parameters can be assisted by rock physics theoretical models and rock physics experiments. The rock physics theoretical model is a theoretical method for studying the rock components, porosity, pore shape and fluid properties and the overall elastic parameters of the rock according to mathematical formulas and physical principles. The rock physics experiment is a practical method for obtaining rock test results and summarizing the internal physical properties and elastic laws of the rock. Systematic rock physics experiments and theoretical model research can provide theoretical support and method support for the elastic parameter law of shale.

[0003] In the process of implementing the present application, the inventors found that at least the following problems exist in the prior art:

[0004] Based on the research on the shale of Wufeng-Longmaxi Formation in Sichuan Basin, it is shown that the clay content and directional arrangement of clay are the main factors affecting the anisotropy of shale. Since there are few theoretical researches on the directional arrangement of clay in China, the directional arrangement of clay and the influence of the microstructure of shale on anisotropy are not considered in the rock physics modeling of shale. In the anisotropy parameter inversion of logging data, the conventional anisotropy rock physics theoretical model is mostly used, which finally leads to the lack of reasonable theoretical support and the lack of actual rock physics significance of the inversion result. Therefore, it is necessary to establish a shale logging data anisotropy parameter inversion method combined with rock physics experiments and rock physics theories. SUMMARY

[0005] In view of the above problems, the present application provides an anisotropy parameter inversion method, device, equipment and storage medium.

[0006] The present application provides an anisotropy parameter inversion method, comprising:

[0007] S1: establishing a rock physics model of shale anisotropy with multi-mineral mixing, complex pore combination and anisotropic clay;

[0008] S2: performing rock physics testing to obtain rock physics testing data and anisotropy parameters of the rock sample;

[0009] S3: combining the petrophysical test data, performing petrophysical analysis, obtaining the petrophysical model and related parameters suitable for the shale rock structure and the physical mechanism of the theoretical model;

[0010] S4: based on the petrophysical model of the shale obtained by the petrophysical analysis, performing the pore aspect ratio and clay orientation degree inversion on the logging data;

[0011] S5: substituting the parameters obtained by the inversion into the anisotropic petrophysical model of the shale, and combining the definition of the Thomsen anisotropic parameter, the anisotropic parameter is calculated.

[0012] In some embodiments, in the petrophysical model, the inverted parameters are the pore aspect ratio α and the clay orientation index.

[0013] In some embodiments, the elastic stiffness matrix of the clay as the anisotropic element is in the form of:

[0014] (1)

[0015] In formula (1), is the mineral arrangement angle distribution, is the elastic stiffness matrix when the clay mineral arrangement is randomly distributed, is the corresponding elastic parameter matrix when the clay mineral particles are arranged in a directional arrangement, is the elastic stiffness matrix of the clay;

[0016] The pore aspect ratio corresponds to the rock elastic parameter in the petrophysical model.

[0017] In some embodiments, the petrophysical test is performed to obtain the petrophysical test data, specifically including:

[0018] The mineral composition, acoustic velocity, anisotropic parameter, porosity and pore structure information of the core test data;

[0019] The specific method for obtaining the acoustic velocity includes: sampling the shale rock in the study area, performing anisotropic parameter experiments, and obtaining the acoustic velocity information of the rock sample in the vertical direction, the horizontal direction and the 45º direction of the bedding;

[0020] The specific method for obtaining the anisotropic parameter data includes:

[0021] The corresponding stiffness matrix of the anisotropic petrophysical equivalent model is:

[0022] (2)

[0023] Wherein,

[0024] (3)

[0025] (4)

[0026] (5)

[0027] (6)

[0028] (7)

[0029] (8)

[0030] : P-wave velocity in the direction of 45° to the vertical symmetry axis of the bedding plane;

[0031] V p : P-wave velocity in the vertical direction;

[0032] V sh : P-wave velocity in the horizontal direction;

[0033] : P-wave velocity in the direction of 0° to the vertical symmetry axis of the bedding plane;

[0034] : P-wave velocity in the direction of 90° to the vertical symmetry axis of the bedding plane;

[0035] : P-wave velocity in the direction of 90° to the vertical symmetry axis of the bedding plane;

[0036] Combining the anisotropy parameter expressions proposed by Thomsen:

[0037] (9)

[0038] : V p Difference between P-wave velocities in the vertical and horizontal directions;

[0039] (10)

[0040] : V sh Difference between S-wave velocities in the vertical and horizontal directions;

[0041] (11)

[0042] : P-wave variation parameter.

[0043] In some embodiments, the performing petrophysical test and obtaining petrophysical test data further comprises: a pore aspect ratio of the rock and a clay orientation index of the rock sample.

[0044] The pore aspect ratio of the rock and the clay orientation index of the rock sample cannot be directly obtained in the logging data, and therefore, a pore aspect ratio and clay orientation index inversion method commonly used in core test data and logging data processing needs to be established.

[0045] In some embodiments, the specific method for performing pore aspect ratio and clay orientation degree inversion of the logging data based on the petrophysical model of the shale subjected to the petrophysical analysis comprises:

[0046] In combination with the mineral components, porosity and density information of the test data, the constructed petrophysical model forward is performed, the upper and lower boundaries of the clay orientation index and the change range of the pore aspect ratio are set as the search interval by using the grid search method, and the elastic parameters of the shale petrophysical model are calculated and ;

[0047] The target function and constraint of the shale petrophysical model are constructed by using the elastic parameters and , the target function is solved, and the maximum likelihood value is obtained as the inversion parameter result.

[0048] In some embodiments, the target function and constraint of the shale petrophysical model are constructed by using the elastic parameters and , specifically comprising:

[0049] Target function:

[0050]

[0051] (12)

[0052] Wherein,

[0053] : represents the clay orientation degree, which is a description parameter of the arrangement degree of the clay mineral;

[0054] α: represents the pore aspect ratio of the brittle mineral in the shale;

[0055] J : target function;

[0056] C 33 , C 44 : actual measured value calculated by logging;

[0057] C 33model , C 44model: elastic parameters of the shale rock physics model, that is, rock physics model elastic values corresponding to the rock physics model forward calculation;

[0058] Constraints: clay mineral orientation index and pore aspect ratio with error within 5%.

[0059] The embodiment of the application provides an anisotropy parameter inversion device, which comprises:

[0060] The rock physics model establishing module, the rock physics testing module, the rock physics analysis module, the pore aspect ratio and clay orientation degree inversion module, and the anisotropy parameter calculation module;

[0061] The rock physics model establishing module: a shale anisotropic rock physics model with multi-mineral mixing, complex pore combination and anisotropic clay is established;

[0062] The rock physics testing module: rock physics testing is performed, and rock physics testing data and anisotropy parameters of a rock sample are obtained;

[0063] The rock physics analysis module: rock physics analysis is performed in combination with rock physics testing data, and a rock physics model and related parameters suitable for a shale rock structure and a theoretical model physical mechanism are obtained;

[0064] The pore aspect ratio and clay orientation degree inversion module: pore aspect ratio and clay orientation degree inversion is performed on logging data based on a shale rock physics model of rock physics analysis;

[0065] The anisotropy parameter calculation module: parameters obtained through inversion are substituted into the shale anisotropic rock physics model, and anisotropy parameters are obtained in combination with the definition of Thomsen anisotropy parameters.

[0066] The embodiment of the application provides an anisotropy parameter inversion device, which comprises a memory and a processor, and the memory stores a computer program which is executed by the processor to execute the anisotropy parameter inversion method.

[0067] The embodiment of the application provides a storage medium which stores a computer program capable of being executed by one or more processors and capable of being used to implement the anisotropy parameter inversion method.

[0068] The application provides an anisotropy parameter inversion method, device, equipment and storage medium,

[0069] The effect of the calculated anisotropy parameters of the logging data is good. The inversion fully considers the influence of the pore structure, the clay particles with directional arrangement and the complex mineral combination on the anisotropy of the shale, and combines the supervision and optimization of the petrophysical test data to better ensure the accuracy of the anisotropy parameters of the logging data and the accuracy of the model itself. Finally, the calculation result is consistent with the actual data, and has certain improvement on the data processing and interpretation. BRIEF DESCRIPTION OF DRAWINGS

[0070] In the following, the present application will be described in more detail based on the embodiments and with reference to the drawings.

[0071] Figure 1 An implementation flowchart of an anisotropy parameter inversion method provided for the embodiments of the present application is shown in the figure.

[0072] Figure 2 A shale anisotropy petrophysical model provided for the embodiments of the present application is shown in the figure.

[0073] Figures 3(a)-3(c) are schematic diagrams of clay particle arrangement provided for the embodiments of the present application, in which M is the longitudinal wave modulus, G is the shear modulus, and C 11 , C 33 , C 44 , C 66 , etc. are parameters in the elastic parameter matrix.

[0074] Figure 4 A relationship diagram of the elastic parameters of the clay mineral and the angle (clay directional index) provided for the embodiments of the present application is shown in the figure.

[0075] Figure 5 A well logging curve data diagram of Well A provided for the embodiments of the present application is shown in the figure.

[0076] Figures 6(a)-(b) are effect diagrams of shale petrophysical anisotropy parameter solving of Well A provided for the embodiments of the present application.

[0077] Figures 7(a)-(b) are well logging curve data diagrams of Well B provided for the embodiments of the present application.

[0078] Figures 8(a)-(b) are effect diagrams of shale petrophysical anisotropy parameter solving of Well B provided for the embodiments of the present application.

[0079] Figures 9(a)-(c) are schematic diagrams of obtaining acoustic velocity information of a rock sample in the direction of stratification provided for the embodiments of the present application. DETAILED DESCRIPTION

[0080] In order to make the purposes, technical solutions and advantages of the present application clearer, the following further describes the present application in conjunction with the accompanying drawings, and the described embodiments should not be regarded as limiting the present application. All other embodiments obtained by those of ordinary skill in the art without creative effort fall within the scope of the present application.

[0081] In the following description, "some embodiments" are referred to, which describe a subset of all possible embodiments, but it can be understood that "some embodiments" can be the same subset or different subsets of all possible embodiments, and can be combined with each other without conflict.

[0082] If similar descriptions of "first\second\third" appear in the application file, the following explanations are added. In the following description, the terms "first\second\third" referred to are only to distinguish similar objects, and do not represent a specific order of the objects. It can be understood that "first\second\third" can be interchanged in a specific order or sequence as allowed, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein.

[0083] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs. The terms used herein are only for the purpose of describing the embodiments of the present application and are not intended to limit the present application.

[0084] Before introducing the anisotropy parameter inversion method provided by the embodiments of the present application, the problems existing in the related art are briefly introduced:

[0085] Due to the internal clay, organic matter, directional arrangement of micro-cracks and complex mineral components of shale oil and gas reservoirs, the elastic properties of shale show strong anisotropy, and there are significant response characteristics on seismic and logging. The research on the relationship between the internal structural properties of shale reservoirs and anisotropy parameters can be assisted by rock physics theoretical models and rock physics experiments. The rock physics theoretical model is a theoretical method for studying the rock components, porosity, pore shape and fluid properties and the overall elastic parameter law of the rock according to mathematical formulas and physical principles. The rock physics experiment is a practical method for obtaining rock test results and summarizing the internal physical properties and elastic law of the rock. Systematic rock physics experiments and theoretical model research can provide theoretical support and method support for the elastic parameter law of shale.

[0086] In the process of implementing the present application, the inventors have found that there are at least the following problems in the prior art:

[0087] Based on the research on the shale of Wufeng-Longmaxi Formation in Sichuan Basin, it is shown that the clay content and the directional arrangement of clay are the main factors affecting the anisotropy of shale. Since the theoretical research on the directional arrangement of clay is less carried out in China, the influence of the directional arrangement of clay and the microstructure of shale on the anisotropy is not considered in the petrophysical modeling of shale. In the anisotropy parameter inversion of logging data, the conventional anisotropy petrophysical theoretical model is mostly used, which finally leads to the lack of reasonable theoretical support and the lack of actual petrophysical significance of the inversion result. Therefore, it is necessary to establish a shale logging data anisotropy parameter inversion method combining petrophysical experiment and petrophysical theory.

[0088] Based on the problems in the related art, the embodiment of the present application provides an anisotropy parameter inversion method, which is applied to an anisotropy parameter inversion device. The anisotropy parameter inversion device can be an electronic device, such as a computer, a mobile terminal, etc. The function realized by the anisotropy parameter inversion method provided by the embodiment of the present application can be realized by calling program code by the processor of the electronic device, wherein the program code can be saved in the computer storage medium.

[0089] The present application takes advantage of the quantitative description of shale microstructure and petrophysical characteristics by petrophysical experiment, and invents a method of using the petrophysical test data of core samples in the well as a label to supervise and train the shale petrophysical theoretical model, so as to obtain the petrophysical model parameters conforming to the actual reservoir, and make the petrophysical model applicable to the solution of anisotropy parameters of shale logging data.

[0090] The shale petrophysical model adopted by the present application mainly considers the characteristics of the multi-mineral mixture, the complex pore structure and the directional arrangement of clay of shale. The matrix part of the petrophysical model is composed of clay and brittle minerals and organic matter, and the three minerals have their own pore structure and pore size, which together represent the pore system of shale. The clay mineral particles are regarded as anisotropic elements, and the elastic parameters of the clay minerals are calculated in combination with the directional arrangement of the clay minerals. The elastic parameters of the brittle minerals are calculated by using the average value of the Hashin-Shtrikman boundary.

[0091] First, the organic matter and brittle minerals are considered to be isotropic, and the elastic parameters of the brittle minerals containing pores and the elastic parameters of the elastic parameters containing pores are calculated by using the differential effective medium (DEM) theory. The two are respectively optimized according to the total organic carbon content to adopt the self-consistent approximation (SCA) and the differential effective medium (DEM) model to establish the physical model of the mixture with or without brittle minerals containing pores and organic matter. When the organic carbon content is small, the differential effective medium model is adopted, the brittle minerals are used as the background medium, and the organic matter is added as the inclusions; when the organic carbon content is large, a part of the organic carbon content can be considered to play a role of skeleton support, and the combined model of SCA-DEM is adopted. Based on the above established mixed model, the elastic parameters of the mixture containing pores and not containing pores can be calculated.

[0092] Then, based on the anisotropic differential effective medium model, the elastic parameters of the clay minerals containing pores and bound water are calculated. According to the clay content, the anisotropic self-consistent approximation and the anisotropic differential effective medium model are preferably adopted to calculate the equivalent elastic parameters of the rock matrix and the dry rock skeleton. When the clay content is large, the clay is used as the background medium of the shale rock, the brittle minerals and the organic matter are used as the inclusions, and the differential effective medium model is used to calculate the corresponding equivalent elastic parameters of the shale matrix and the dry skeleton of the shale. If the clay content is small, the mixture of the brittle minerals and the organic matter is used as the background medium of the shale rock, and the clay is used as the inclusion, and the anisotropic self-consistent approximation model and the anisotropic differential effective medium model are used to calculate the corresponding equivalent elastic parameters of the shale matrix and the dry skeleton of the shale.

[0093] The Wood formula is used to calculate the elastic parameters of the oil-gas-water mixture. The Brown-Korringa equation is used to calculate the anisotropic rock physical elastic parameters of the saturated fluid.

[0094] The idea of the present application is to use core test data as labels to supervise the training of the shale rock physical model, so as to obtain the rock physical model parameters conforming to the actual reservoir. Then, the vertical wave velocity, the transverse wave velocity and the density information in the logging data, the pore aspect ratio and the clay orientation index in the rock physical model are substituted into the rock physical model, and finally the anisotropic parameter values of the shale layer logging are calculated.

[0095] Example One

[0096] The embodiment of the present application provides an anisotropic parameter inversion method, Figure 1 The implementation flowchart of the anisotropic parameter inversion method provided by the embodiment of the present application is shown in Figure 1 as shown, comprising:

[0097] S1: establishing a shale anisotropic rock physical model of a multi-mineral mixture, a complex pore combination and anisotropic clay;

[0098] S2: perform rock physical test, obtain rock physical test data and rock sample anisotropy parameters;

[0099] S3: perform rock physical analysis in combination with the rock physical test data, and obtain a rock physical model and related parameters applicable to the shale rock structure and theoretical model physical mechanism;

[0100] S4: perform pore aspect ratio and clay orientation degree inversion on the logging data based on the rock physical model of the shale obtained through the rock physical analysis;

[0101] S5: substitute the parameters obtained through the inversion into the rock physical model of the shale anisotropy, and solve the anisotropy parameters in combination with the definition of the Thomsen anisotropy parameters.

[0102] The anisotropy parameter inversion method provided in the application has good effects on calculating the anisotropy parameters of the logging data. The inversion fully considers the influence of the pore structure, the clay particles in directional arrangement and the complex mineral combination on the anisotropy of the shale, and combines the supervision and optimization of the rock physical test data, so as to better ensure the accuracy of the anisotropy parameters of the logging data and the accuracy of the model itself. Finally, the calculation result is consistent with the actual data, and has certain improvement on data processing and interpretation.

[0103] Example Two

[0104] Based on the foregoing embodiments, the embodiments of the application further provide an anisotropy parameter inversion method, which comprises:

[0105] S1: establish a rock physical model of shale anisotropy with multiple mineral mixtures, complex pore combinations and anisotropic clay;

[0106] In some embodiments, in the rock physical model, the inversion parameters are a pore aspect ratio α and a clay orientation index;

[0107] S2: perform rock physical test, obtain rock physical test data and rock sample anisotropy parameters;

[0108] S3: perform rock physical analysis in combination with the rock physical test data, and obtain a rock physical model and related parameters applicable to the shale rock structure and theoretical model physical mechanism;

[0109] S4: perform pore aspect ratio and clay orientation degree inversion on the logging data based on the rock physical model of the shale obtained through the rock physical analysis;

[0110] S5: substitute the parameters obtained through the inversion into the rock physical model of the shale anisotropy, and solve the anisotropy parameters in combination with the definition of the Thomsen anisotropy parameters.

[0111] The application provides an anisotropy parameter inversion method, and the effect of calculating the anisotropy parameters of logging data is good. The inversion fully considers the influence of pore structure, directionally arranged clay particles and complex mineral combination on the anisotropy of shale, and combines with the supervision and optimization of petrophysical test data to better ensure the accuracy of the anisotropy parameters of logging data and the accuracy of the model itself. Finally, the calculation result is consistent with the actual data, and has certain improvement on data processing and interpretation.

[0112] Example Three

[0113] Based on the foregoing embodiments, the embodiments of the application further provide an anisotropy parameter inversion method, comprising:

[0114] S1: establishing a petrophysical model of anisotropy of shale with multi-mineral mixing, complex pore combination and anisotropic clay;

[0115] In some embodiments, in the petrophysical model, the inversion parameters are pore aspect ratio a and clay directional index;

[0116] In some embodiments, the elastic stiffness matrix of the anisotropic element formed by the clay is:

[0117] (1)

[0118] In formula (1), a is a pore aspect ratio, is a mineral arrangement angle distribution, is an elastic stiffness matrix of the clay mineral arranged in a random distribution, is an elastic parameter matrix corresponding to the clay mineral particles arranged in a directional arrangement, is an elastic stiffness matrix of the clay;

[0119] When the angle is 0 degree, it corresponds to a high clay directional arrangement direction concentration; When the angle is 90 degrees, it represents that the clay mineral particles are randomly distributed, and the elastic characteristics are isotropic; The angle describes the distribution form of the curve in the probability density distribution diagram of the arrangement direction of the clay mineral particles; the clay directional arrangement can be obtained by X-ray diffraction using an XRD diffractometer;

[0120] The pore aspect ratio corresponds to the rock elastic parameters in the petrophysical model; the size of the pore aspect ratio can affect the size of the elastic parameter values of the overall petrophysical model, and when the pore aspect ratio is small, the corresponding rock elastic parameter values also decrease. The pore aspect ratio can be obtained by scanning electron microscopy or CT scanning, but in general, only the pore aspect ratio in a certain range can be counted;

[0121] Therefore, in the petrophysical theoretical model, the recommended parameter value is usually used to specify the pore aspect ratio of the petrophysical model;

[0122] S2: Perform petrophysical testing to obtain petrophysical test data and anisotropy parameters of the rock sample;

[0123] S3: Perform petrophysical analysis in combination with the petrophysical test data to obtain a petrophysical model and related parameters applicable to the physical mechanism of the shale rock structure and the theoretical model;

[0124] S4: Perform pore aspect ratio and clay orientation degree inversion on the logging data based on the petrophysical model of the shale obtained through the petrophysical analysis;

[0125] S5: Substitute the parameters obtained through the inversion into the petrophysical model of the shale anisotropy, and calculate the anisotropy parameters in combination with the definition of the Thomsen anisotropy parameters.

[0126] The anisotropy parameter inversion method provided in the application has good effects on calculating the anisotropy parameters of the logging data. The inversion fully considers the influence of the pore structure, the clay particles in the directional arrangement, and the complex mineral combination on the anisotropy of the shale, and combines the supervision and optimization of the petrophysical test data to better ensure the accuracy of the anisotropy parameters of the logging data and the accuracy of the model itself. Finally, the calculation result is consistent with the actual data, and has certain improvement on data processing and interpretation.

[0127] Example Four

[0128] Based on the foregoing embodiments, the embodiments of the application further provide an anisotropy parameter inversion method, which comprises:

[0129] S1: Establish a petrophysical model of shale anisotropy with multiple mineral mixtures, complex pore combinations, and anisotropic clay;

[0130] In some embodiments, in the petrophysical model, the inversion parameters are the pore aspect ratio a and the clay orientation index;

[0131] In some embodiments, the elastic stiffness matrix of the clay as the anisotropic element has the form of:

[0132] (1)

[0133] In formula (1), a is the pore aspect ratio, is the mineral arrangement angle distribution, is the elastic stiffness matrix when the clay mineral arrangement is random, is the corresponding elastic parameter matrix when the clay mineral particles are arranged in a directional arrangement, is the elastic stiffness matrix of clay;

[0134] When the angle is 0 degree, it corresponds to the high concentration of clay orientation arrangement direction; When the angle is 90 degrees, it represents that the clay mineral particles are randomly distributed, and the elastic characteristics are isotropic; The angle describes the distribution form of the curve in the probability density distribution diagram of the arrangement direction of the clay mineral particles; the clay orientation arrangement can be obtained by X-ray diffraction using an XRD diffractometer;

[0135] The pore aspect ratio corresponds to the elastic parameters of the rock physics model; the size of the pore aspect ratio can affect the numerical value of the elastic parameters of the overall rock physics model, and when the pore aspect ratio is small, the numerical value of the corresponding rock elastic parameters also decreases. It can be obtained by scanning electron microscopy or CT scanning, but generally only the pore aspect ratio in a certain range can be counted;

[0136] Therefore, in the rock physics theoretical model, the recommended parameter value for specifying the pore aspect ratio of the rock physics model is usually used;

[0137] S2: performing rock physics testing to obtain rock physics test data and anisotropy parameters of the rock sample;

[0138] In some embodiments, the rock physics testing to obtain the rock physics test data specifically includes:

[0139] The mineral composition, acoustic velocity, anisotropy parameters, porosity and pore structure information of the core test data;

[0140] The specific method for obtaining the acoustic velocity includes: sampling the shale rock in the study area, performing anisotropy parameter experiments, and obtaining acoustic velocity information of the rock sample in the vertical direction, the horizontal direction and the 45º direction of the bedding;

[0141] The specific method for obtaining the anisotropy parameter data includes:

[0142] The corresponding stiffness matrix of the rock physics equivalent model of the anisotropic rock is:

[0143] (2)

[0144] wherein,

[0145] (3)

[0146] (4)

[0147] (5)

[0148] (6)

[0149] (7)

[0150] (8)

[0151] : rock density;

[0152] V p : P-wave velocity;

[0153] V sh : S-wave velocity;

[0154] : P-wave velocity in the direction of 45º to the normal to the bedding plane;

[0155] : P-wave velocity in the direction of 0º to the normal to the bedding plane;

[0156] : P-wave velocity in the direction of 90º to the normal to the bedding plane;

[0157] Fig. 9(a)-(c) are schematic diagrams for obtaining acoustic velocity information of rock samples in each direction of bedding provided by the embodiment of the present application, as shown in Fig. 9(a)-(c), anisotropy parameter experiment is performed, acoustic velocity information of rock samples in the vertical direction of bedding is shown in Fig. 9(a), the P-wave velocity of the 90° sample, i.e. the vertical bedding sample, tested is ; acoustic velocity information in the horizontal direction is shown in Fig. 9(b), the P-wave velocity of the 0° sample (parallel bedding sample) tested is ; acoustic velocity information in the 45º direction is shown in Fig. 9(c), the P-wave velocity of the 45° sample tested is ; acoustic velocity information in the 90º direction.

[0158] Combined with the anisotropy parameter expression proposed by Thomsen:

[0159] (9)

[0160] : V p Difference of P-wave velocity in the vertical and horizontal directions;

[0161] (10)

[0162] : V shThe difference of the shear wave velocity in the vertical direction and the horizontal direction;

[0163] (11)

[0164] The P-wave variation parameter.

[0165] S3: combining the petrophysical test data, performing petrophysical analysis, obtaining the petrophysical model and related parameters suitable for the shale rock structure and the physical mechanism of the theoretical model;

[0166] S4: performing the pore aspect ratio and clay orientation degree inversion on the logging data based on the petrophysical model of the shale obtained through the petrophysical analysis;

[0167] S5: substituting the parameters obtained through the inversion into the anisotropy petrophysical model of the shale, and combining the definition of the Thomsen anisotropy parameter to obtain the anisotropy parameter.

[0168] The anisotropy parameter inversion method provided in the application has better effect on calculating the anisotropy parameter of the logging data. The inversion fully considers the influence of the pore structure, the clay particles in the directional arrangement and the complex mineral combination on the anisotropy of the shale, and combines the supervision and optimization of the petrophysical test data to better ensure the accuracy of the anisotropy parameter of the logging data and the accuracy of the model itself. Finally, the calculation result is consistent with the actual data, and has certain improvement on the data processing and interpretation.

[0169] Example Five

[0170] Based on the foregoing embodiments, the embodiments of the application further provide an anisotropy parameter inversion method, comprising:

[0171] S1: establishing an anisotropy petrophysical model of shale with multi-mineral mixture, complex pore combination and anisotropic clay;

[0172] In some embodiments, in the petrophysical model, the inversion parameters are the pore aspect ratio α and the clay orientation index;

[0173] In some embodiments, the elastic stiffness matrix of the clay as the anisotropic element has the form of:

[0174] (1)

[0175] In formula (1) is the mineral arrangement angle distribution, is the elastic stiffness matrix when the clay mineral arrangement is random distribution, is the corresponding elastic parameter matrix when the clay mineral particles are arranged in a directional arrangement, is the elastic stiffness matrix of clay;

[0176] When the angle is 0 degree, it corresponds to the high concentration of clay orientation arrangement direction; When the angle is 90 degrees, it represents that the clay mineral particles are randomly distributed, and the elastic characteristics are isotropic; The angle describes the distribution form of the curve in the probability density distribution diagram of the arrangement direction of the clay mineral particles; the clay orientation arrangement can be obtained by X-ray diffraction using an XRD diffractometer;

[0177] The pore aspect ratio corresponds to the elastic parameters of the rock physics model; the size of the pore aspect ratio can affect the numerical value of the elastic parameters of the overall rock physics model, and when the pore aspect ratio is small, the numerical value of the corresponding rock elastic parameters also decreases. It can be obtained by scanning electron microscopy or CT scanning, but generally only the pore aspect ratio within a certain range can be counted;

[0178] Therefore, in the rock physics theoretical model, the recommended parameter value for specifying the pore aspect ratio of the rock physics model is usually used;

[0179] S2: performing rock physics testing to obtain rock physics test data and anisotropy parameters of the rock sample;

[0180] In some embodiments, the rock physics testing to obtain the rock physics test data specifically includes:

[0181] Mineral composition, acoustic velocity, anisotropy parameters, porosity and pore structure information of the core test data;

[0182] The specific method for obtaining the acoustic velocity includes: sampling the shale rock in the study area, performing anisotropy parameter experiments, and obtaining acoustic velocity information of the rock sample in the vertical direction, the horizontal direction and the 45º direction of the bedding;

[0183] The specific method for obtaining the anisotropy parameter data includes:

[0184] The corresponding stiffness matrix of the anisotropic rock physics equivalent model is:

[0185] (2)

[0186] wherein,

[0187] (3)

[0188] (4)

[0189] (5)

[0190] (6)

[0191] (7)

[0192] (8)

[0193] : rock density;

[0194] V p : P-wave velocity;

[0195] V sh : S-wave velocity;

[0196] : P-wave velocity in the direction of 45º to the vertical symmetry axis of the bedding plane;

[0197] : P-wave velocity in the direction of 0º to the vertical symmetry axis of the bedding plane;

[0198] : P-wave velocity in the direction of 90º to the vertical symmetry axis of the bedding plane;

[0199] In combination with the anisotropy parameter expressions proposed by Thomsen:

[0200] (9)

[0201] : V p Difference in P-wave velocity between vertical and horizontal directions;

[0202] (10)

[0203] : V sh Difference in S-wave velocity between vertical and horizontal directions;

[0204] (11)

[0205] : P-wave variation parameter.

[0206] In some embodiments, the performing petrophysical tests and obtaining petrophysical test data further comprises, in particular: a pore aspect ratio of the rock and a clay orientation index of the rock sample;

[0207] The pore aspect ratio of the rock and the clay orientation index of the rock sample cannot be directly obtained in logging data, and thus a pore aspect ratio and clay orientation index inversion method applicable to core test data and logging data processing needs to be established;

[0208] S3: Combined with rock physical test data, rock physical analysis is performed to obtain a rock physical model and related parameters applicable to shale rock structure and physical mechanism of a theoretical model;

[0209] S4: The pore aspect ratio and clay orientation degree of the shale are inversed based on the rock physical model of the shale obtained through the rock physical analysis;

[0210] S5: The parameters obtained through the inversion are substituted into the anisotropy rock physical model of the shale, and anisotropy parameters are calculated in combination with the definition of the Thomsen anisotropy parameters.

[0211] The anisotropy parameter inversion method provided in the application has a better effect on calculating anisotropy parameters of logging data. The inversion fully considers the influence of pore structure, clay particles in directional arrangement and complex mineral combination on the anisotropy of shale, and combines with the supervision and optimization of rock physical test data to better ensure the accuracy of anisotropy parameters of logging data and the accuracy of the model itself. Finally, the calculation result is consistent with the actual data, and has certain improvement on data processing and interpretation.

[0212] Example Six

[0213] Based on the foregoing embodiments, the embodiments of the application further provide an anisotropy parameter inversion method, comprising:

[0214] S1: A shale anisotropy rock physical model of a multi-mineral mixture, complex pore combination and anisotropic clay is established;

[0215] In some embodiments, in the rock physical model, the inversed parameters are a pore aspect ratio α and a clay orientation index;

[0216] In some embodiments, the elastic stiffness matrix of the anisotropic element formed by the clay is:

[0217] (1)

[0218] In formula (1) is a mineral arrangement angle distribution, is an elastic stiffness matrix when the clay mineral is arranged in a random distribution, is an elastic parameter matrix corresponding to the clay mineral particles arranged in a directional arrangement, is an elastic stiffness matrix of the clay;

[0219] When the angle is 0 degree, it corresponds to the high concentration of clay orientation arrangement direction; When the angle is 90 degrees, it represents that the clay mineral particles are randomly distributed, and the elastic characteristics are isotropic; The angle describes the distribution form of the curve in the probability density distribution diagram of the arrangement direction of the clay mineral particles; the clay orientation arrangement can be obtained by XRD diffraction using X-ray diffraction;

[0220] The pore aspect ratio corresponds to the rock elastic parameter in the rock physical model; the size of the pore aspect ratio can affect the numerical value of the elastic parameter of the overall rock physical model, and when the pore aspect ratio is small, the corresponding rock elastic parameter value also decreases. It can be obtained by scanning electron microscopy or CT scanning, but generally only the pore aspect ratio in a certain range can be counted;

[0221] Therefore, in the rock physical theory model, the recommended parameter value for specifying the pore aspect ratio of the rock physical model is usually used;

[0222] S2: performing rock physical testing to obtain rock physical test data and anisotropy parameters of the rock sample;

[0223] In some embodiments, the rock physical testing to obtain the rock physical test data specifically includes:

[0224] Mineral composition, acoustic velocity, anisotropy parameters, porosity and pore structure information of the core test data;

[0225] The specific method for obtaining the acoustic velocity includes: sampling the shale rock in the study area, performing anisotropy parameter experiments, and obtaining acoustic velocity information of the rock sample in the vertical direction, the horizontal direction and the 45º direction of the bedding;

[0226] The specific method for obtaining the anisotropy parameter data includes:

[0227] The corresponding stiffness matrix of the anisotropic rock physical equivalent model is:

[0228] (2)

[0229] wherein,

[0230] (3)

[0231] (4)

[0232] (5)

[0233] (6)

[0234] (7)

[0235] (8)

[0236] : rock density;

[0237] V p : P-wave velocity;

[0238] V sh : S-wave velocity;

[0239] : P-wave velocity in the direction of 45° to the vertical symmetry axis of the bedding plane;

[0240] : P-wave velocity in the direction of 0° to the vertical symmetry axis of the bedding plane;

[0241] : P-wave velocity in the direction of 90° to the vertical symmetry axis of the bedding plane;

[0242] In combination with the anisotropy parameter expression proposed by Thomsen:

[0243] (9)

[0244] : V p Difference of P-wave velocity in vertical and horizontal directions;

[0245] (10)

[0246] : V sh Difference of S-wave velocity in vertical and horizontal directions;

[0247] (11)

[0248] : P-wave anisotropy parameter.

[0249] In some embodiments, the performing petrophysical test and obtaining petrophysical test data further comprises: a pore aspect ratio of the rock and a clay orientation index of the rock sample;

[0250] The pore aspect ratio of the rock and the clay orientation index of the rock sample cannot be directly obtained in the logging data, and therefore a pore aspect ratio and clay orientation index inversion method commonly used in core test data and logging data processing needs to be established;

[0251] S3: combining the petrophysical test data, performing petrophysical analysis, obtaining a petrophysical model and related parameters suitable for the shale rock structure and the physical mechanism of the theoretical model;

[0252] S4: performing porosity aspect ratio and clay orientation degree inversion on the logging data based on the petrophysical model of the shale obtained through the petrophysical analysis;

[0253] In some embodiments, the specific method of performing porosity aspect ratio and clay orientation degree inversion on the logging data based on the petrophysical model of the shale obtained through the petrophysical analysis includes:

[0254] In combination with the mineral components, porosity, and density information of the test data, the constructed petrophysical model is forward calculated, the upper and lower boundaries of the clay orientation index and the variation range of the porosity aspect ratio are set as the search interval through the grid search method, and the elastic parameters of the shale petrophysical model are calculated and ;

[0255] The target function and constraint of the shale petrophysical model are constructed through the elastic parameters and , the target function is solved, and the maximum likelihood value is obtained as the inversion parameter result;

[0256] S5: substituting the parameters obtained through the inversion into the anisotropy petrophysical model of the shale, and combining the definition of the Thomsen anisotropy parameter to obtain the anisotropy parameter.

[0257] The anisotropy parameter inversion method provided in the application has a good effect on calculating the anisotropy parameter of the logging data. The inversion fully considers the influence of the pore structure, the clay particles in the directional arrangement, and the complex mineral combination on the anisotropy of the shale, and combines the supervision and optimization of the petrophysical test data to better ensure the accuracy of the anisotropy parameter of the logging data and the accuracy of the model itself. Finally, the calculation result is consistent with the actual data, and has certain improvement on data processing and interpretation.

[0258] Example Seven

[0259] Based on the foregoing embodiments, the embodiments of the application further provide an anisotropy parameter inversion method, including:

[0260] S1: establishing a shale anisotropy petrophysical model with multiple mineral mixtures, complex pore combinations, and anisotropic clay;

[0261] In some embodiments, in the petrophysical model, the inversion parameters are the porosity aspect ratio α and the clay orientation index;

[0262] In some embodiments, the elastic stiffness matrix of the clay as an anisotropic element is composed of:

[0263] (1)

[0264] In formula (1), the elastic stiffness matrix of the clay is composed of is the angle distribution of the mineral arrangement, is the elastic stiffness matrix when the clay mineral arrangement is randomly distributed, is the elastic parameter matrix corresponding to the clay mineral particle arrangement in the direction of the directional arrangement, is the elastic stiffness matrix of the clay;

[0265] When the angle is 0 degrees, it corresponds to the high concentration of the clay directional arrangement direction; When the angle is 90 degrees, it represents the random distribution of the clay mineral particles, and the elastic characteristics are isotropic; The angle describes the distribution form of the curve in the probability density distribution diagram of the arrangement direction of the clay mineral particles; the directional arrangement of the clay can be obtained by XRD diffraction using X-ray diffraction;

[0266] The pore aspect ratio corresponds to the rock elastic parameter in the rock physical model; the size of the pore aspect ratio can affect the size of the elastic parameter value of the overall rock physical model, and when the pore aspect ratio is small, the corresponding rock elastic parameter value also decreases. It can be obtained by scanning electron microscopy or CT scanning, but generally only a certain range of pore aspect ratios can be counted;

[0267] Therefore, in the rock physical theoretical model, the recommended parameter value for specifying the pore aspect ratio of the rock physical model is usually used;

[0268] S2: performing rock physical testing to obtain rock physical test data and anisotropy parameters of the rock sample;

[0269] In some embodiments, the rock physical testing to obtain the rock physical test data specifically includes:

[0270] Mineral composition, acoustic velocity, anisotropy parameters, porosity, and pore structure information of the core test data;

[0271] The specific method for obtaining the acoustic velocity includes: sampling the shale rock in the study area, performing anisotropy parameter experiments, and obtaining acoustic velocity information of the rock sample in the vertical direction, the horizontal direction, and the 45º direction of the bedding;

[0272] The specific method for obtaining the anisotropy parameter data includes:

[0273] The corresponding stiffness matrix of the anisotropic rock physical equivalent model is:

[0274] (2)

[0275] wherein,

[0276] (3)

[0277] (4)

[0278] (5)

[0279] (6)

[0280] (7)

[0281] (8)

[0282] : rock density;

[0283] V p : P-wave velocity;

[0284] V sh : S-wave velocity;

[0285] : P-wave velocity in the direction of 45° to the vertical symmetry axis of the bedding plane;

[0286] : P-wave velocity in the direction of 0° to the vertical symmetry axis of the bedding plane;

[0287] : P-wave velocity in the direction of 90° to the vertical symmetry axis of the bedding plane;

[0288] In combination with the anisotropy parameter expressions proposed by Thomsen:

[0289] (9)

[0290] : V p Difference in P-wave velocity in the vertical and horizontal directions;

[0291] (10)

[0292] : V sh Difference in S-wave velocity in the vertical and horizontal directions;

[0293] (11)

[0294] : P-wave variation parameter.

[0295] In some embodiments, the rock physical test is performed, and the rock physical test data is acquired, and specifically further comprising: a pore aspect ratio of the rock and a clay orientation index of the rock sample;

[0296] The pore aspect ratio of the rock and the clay orientation index of the rock sample cannot be directly obtained in the logging data, and therefore, a pore aspect ratio and clay orientation index inversion method commonly used in core test data and logging data processing needs to be established;

[0297] S3: combining the rock physical test data, performing rock physical analysis, and obtaining a rock physical model and related parameters suitable for the shale rock structure and the theoretical model physical mechanism;

[0298] S4: performing pore aspect ratio and clay orientation degree inversion on the logging data based on the rock physical model of the shale obtained by the rock physical analysis;

[0299] In some embodiments, the specific method of performing pore aspect ratio and clay orientation degree inversion on the logging data based on the rock physical model of the shale obtained by the rock physical analysis comprises:

[0300] Combining the mineral components, porosity, and density information of the test data, performing rock physical model forward modeling, setting the upper and lower boundaries of the clay orientation index and the variation range of the pore aspect ratio as the search interval in a grid search manner, and calculating the elastic parameters of the shale rock physical model and ;

[0301] Constructing an objective function and a constraint of the shale rock physical model by the elastic parameters and , solving the objective function, and obtaining a maximum likelihood value as an inversion parameter result;

[0302] In some embodiments, the constructing an objective function and a constraint of the shale rock physical model by the elastic parameters and specifically comprises:

[0303] Objective function:

[0304] (12)

[0305] wherein,

[0306] : represents the clay orientation degree, which is a description parameter of the arrangement degree of clay minerals;

[0307] a: represents the pore aspect ratio of brittle minerals in shale;

[0308] J : objective function;

[0309] C 33 , C 44 : actual measurement value calculated by logging;

[0310] C 33model , C 44model : elastic parameters of the shale rock physics model, that is, the rock physics model elastic values obtained by forward calculation of the rock physics model;

[0311] Constraint: clay mineral orientation index and pore aspect ratio with an error within 5%.

[0312] S5: substitute the parameters obtained by inversion into the anisotropy rock physics model of shale, and combine the definition of Thomsen anisotropy parameters to obtain the anisotropy parameters.

[0313] The anisotropy parameter inversion method provided by the application has good effect on calculating the anisotropy parameters of logging data. The inversion fully considers the influence of pore structure, clay particles with directional arrangement and complex mineral combination on the anisotropy of shale, and combines the supervision and optimization of rock physics test data to better ensure the accuracy of the anisotropy parameters of logging data and the accuracy of the model itself. Finally, the calculation result is consistent with the actual data, and has certain improvement on data processing and interpretation.

[0314] Example Eight

[0315] Based on the method of Example Seven, the application simulates the use of the anisotropy parameter inversion method of the application on the logging curve of a shale in Sichuan, Figure 1 The implementation flowchart of the anisotropy parameter inversion method provided by the application is shown in Figure 1 , which includes:

[0316] 1) Obtain the core in the well, perform rock physics test, obtain the velocity information in three directions of the core, and calculate the anisotropy parameters of the rock sample according to the Thomsen formula. At the same time, perform a series of rock physics tests such as CT scan test and XRD optical diffraction test of rock physics to obtain more comprehensive core test information.

[0317] 2) Take the velocity and anisotropy parameters and other information of the obtained core sample as labels, perform rock physics analysis on the rock physics model, and obtain more appropriate rock physics model parameters.

[0318] 3) Using the data of longitudinal and transverse wave velocity of well logging curves, combined with the petrophysical model after petrophysical analysis, the inversion objective function is established to conduct the inversion of pore aspect ratio and clay orientation index.

[0319] 4) The inverted pore aspect ratio and clay orientation index are substituted into the petrophysical model to calculate the anisotropic parameters of shale well.

[0320] Figure 2 The schematic diagram for the shale petrophysical model construction is shown in

[0321] The specific petrophysical model construction steps are as follows, and the schematic diagram is shown in Figure 2

[0322] 1) The matrix part of the petrophysical model is composed of clay and brittle mineral and organic matter, and the pore structure and pore size together represent the pore system of shale. The clay mineral particles are regarded as anisotropic elements, and the elastic parameters of clay minerals are calculated in combination with the orientation of clay minerals. The elastic parameters of brittle minerals are calculated by using the average value of Hashin-Shtrikman boundary.

[0323] 2) First, the organic matter and brittle minerals regarded as isotropic are respectively combined with the differential equivalent medium (DEM) theory to calculate the elastic parameters of the brittle mineral containing pores and the organic matter containing pores. The two are respectively established into the mixture physical model with or without pores containing brittle minerals and organic matter according to the total organic carbon content by using the self-consistent approximation (SCA) and differential equivalent medium (DEM) model.

[0324] When the organic carbon content is low, the differential equivalent medium model is used, the brittle mineral is the background medium, and the organic matter is added as the inclusions; when the organic carbon content is high, a part of it can be regarded as a skeleton support, and the combined model of SCA-DEM is used. Based on the above established mixed model, the elastic parameters of the mixture containing pores and not containing pores can be calculated.

[0325] 3) Then, based on the anisotropic differential equivalent medium model (ani-DEM), the elastic parameters of the clay mineral containing pores and bound water are calculated. According to the clay content, the anisotropic self-consistent approximation and the anisotropic differential equivalent medium model are preferably used to calculate the equivalent elastic parameters of the rock matrix and the dry rock skeleton.

[0326] ​When the clay content is high, the clay is the background medium of shale rock, and the brittle mineral and organic matter are the inclusions. The differential effective medium model is used to calculate the equivalent elastic parameters of shale matrix and shale dry skeleton, respectively. When the clay content is low, the mixture of brittle mineral and organic matter is the background medium of shale rock, and the clay is the inclusion. The anisotropic self-consistent approximation model and the anisotropic differential effective medium model are used to calculate the equivalent elastic parameters of shale matrix and shale dry skeleton, respectively.

[0327] 4) The Wood formula is used to calculate the elastic parameters of oil-gas-water mixture. The Brown-Korringa equation, an anisotropic fluid replacement equation, is used to calculate the anisotropic petrophysical elastic parameters of saturated fluid.

[0328] Specifically, the elastic parameters of rock dry skeleton are calculated as follows:

[0329] 1) The elastic parameters of the brittle mineral containing pores, the elastic parameters of the organic matter containing pores, and the elastic parameters of the anisotropic clay containing pores and bound water are calculated, respectively.

[0330] 2) The elastic parameters of the mixture of brittle mineral containing pores and organic matter containing pores are obtained, and the overall shale dry rock skeleton is obtained in combination with the clay containing pores and bound water.

[0331] The elastic parameters of rock matrix are calculated by mixing the above-mentioned substances without adding pores, and finally the elastic parameters of the matrix are obtained.

[0332] The Brown-Korringa equation is used for the final result, and the elastic parameters obtained by the above calculation can be used to obtain the anisotropic petrophysical elastic parameters of saturated fluid.

[0333] Fig. 3 (a) - (c) are schematic diagrams of clay particle arrangement. Fig. 3 (a) represents randomly distributed clay particles, which are isotropic as a whole. Fig. 3 (b) and Fig. 3 (c) represent different degrees of clay particle arrangement, and the velocities in the vertical and horizontal directions are different.

[0334] Figure 4 Fig. 2 is a diagram showing the relationship between the elastic parameters of clay mineral and the angle (clay orientation index). In the figure, Angle is the clay orientation, and Velocity is the velocity. The relationship between the velocity and the degree of arrangement of clay mineral particles can be seen. When the angle is 0º, the difference between the velocities in the two directions is relatively large, and when the angle (clay orientation index) is 90º, the velocities in the two directions remain consistent.

[0335] Figure 5For A well data, the figure, GR curve, P-wave velocity Vp, S-wave velocity Vs, density DEN, porosity Porosity, mineral composition Vol.fract.

[0336] The legend of the last figure is Clay: clay, Calcite: calcite, Pyrite: pyrite, Quartz: quartz, Toc: total organic carbon; pore: porosity. From Sichuan Basin, China, the main processing formation is Longmaxi Formation. The logging curves are distributed in the depth of 3580m-3741m. For the convenience of research, the logging is divided into 13 segments from top to bottom. Each segment contains gamma curve, P-wave and S-wave velocity, density, porosity, and mineral composition information. It can be seen that this is a low porosity logging curve, which is mainly composed of clay, calcite and quartz, and has organic matter and pyrite filling, which belongs to a relatively complex multi-mineral model. The density curve is relatively smooth, and can only distinguish the mineral below 3700m in resolution.

[0337] Fig. 6 (a)-(b) is the effect interpretation drawing of rock physical anisotropy parameter solving of A well data, with the same horizontal and vertical coordinates, in the figure, gamma curve GE, P-wave velocity Vp, S-wave velocity Vs, density DEN, anisotropy parameter , anisotropy parameter , anisotropy parameter . In subgraphs (2) and (3) of Fig. 6, the black curve represents the original logging data of P-wave and S-wave curves, the red curve represents the vertical P-wave and S-wave velocities calculated by the rock physical model, and the blue curve represents the horizontal P-wave and S-wave velocities calculated by the rock physical model. The green scatter data respectively represent the vertical P-wave and S-wave velocities of the core data, and the purple scatter data respectively represent the horizontal P-wave and S-wave velocities of the core data. By comparing the vertical P-wave and S-wave velocity information of the original logging data, it can be seen that the core test data (green scatter) can well match the logging data (black curve). The P-wave and S-wave velocities calculated by the rock physical model (red curve) can be seen that the model data has good fitting effect with the actual logging data (black curve). The model predicted horizontal P-wave and S-wave velocities (blue curve) have consistent trend with the core test data (purple scatter), which to some extent verifies the accuracy of the anisotropy parameter inversion. In subgraph (4) of Fig. 6, the scatter is the density information of the core test, the red curve represents the density information calculated by the model, and the black curve is the original logging density curve. Subgraphs (5), (6) and (7) of Fig. 6 are the anisotropy scatter data obtained by core test and the anisotropy parameter curves calculated by the rock physical model, which can be seen that the anisotropy parameter inverted by the rock physical model is reliable.

[0338] Fig. 7 (a)-(b) are B well data, and A well are data of the same block, with the same horizontal and vertical coordinates, GR curve, P-wave velocity Vp, S-wave velocity Vs, density DEN, porosity Porosity, mineral composition Vol.fract. in the figure. The logging curves are distributed in the depth of 4050m-4250m. The density porosity and mineral composition distribution has consistency with A well, which are shale reservoir logging data with complex mineral combination. The density curve shows relatively stable, and can only distinguish the mineral below 4180m in resolution.

[0339] Fig. 8 (a)-(b) are the effect interpretation drawing of the anisotropy parameter solving of the rock physics of B well data, with the same horizontal and vertical coordinates. In the figure, gamma curve GE, P-wave velocity Vp, S-wave velocity Vs, density DEN, anisotropy parameter , anisotropy parameter , anisotropy parameter It can be seen that the anisotropy parameter prediction effect is relatively stable and can be used between different wells. Comprehensive analysis of two logging data can see that the content of clay and the orientation of clay have certain correlation with the anisotropy of shale.

[0340] The anisotropy parameter inversion method provided in the application has good effect of calculating the anisotropy parameters of logging data. The inversion fully considers the influence of pore structure, clay particles with directional arrangement and complex mineral combination on the anisotropy of shale, and combines with the supervision and optimization of rock physics test data, so as to better ensure the accuracy of logging data anisotropy parameters and the accuracy of the model itself. Finally, the calculation result is consistent with the actual data, which has certain improvement for data processing and interpretation.

[0341] Example Nine

[0342] Based on the foregoing embodiments, the embodiments of the application provide an anisotropy parameter inversion device, which comprises:

[0343] The rock physics model establishing module, the rock physics test module, the rock physics analysis module, the pore aspect ratio and clay orientation degree inversion module and the anisotropy parameter calculation module;

[0344] The rock physics model establishing module: establishing a rock physics model of shale anisotropy with multi-mineral mixture, complex pore combination and anisotropic clay;

[0345] The rock physics test module: performing rock physics test to obtain rock physics test data and rock sample anisotropy parameters;

[0346] The petrophysical analysis module: in combination with petrophysical test data, petrophysical analysis is performed to obtain a petrophysical model and related parameters suitable for shale rock structure and theoretical model physical mechanism;

[0347] The pore aspect ratio and clay orientation inversion module: based on the petrophysical model of shale obtained by petrophysical analysis, pore aspect ratio and clay orientation inversion is performed on the logging data;

[0348] The anisotropy parameter calculation module: the parameters obtained by inversion are substituted into the petrophysical model of shale anisotropy, and the anisotropy parameters are calculated in combination with the definition of Thomsen anisotropy parameters.

[0349] It should be noted that, in the embodiments of the present application, if the anisotropy parameter inversion method described above is implemented in the form of a software function module and sold or used as an independent product, it can also be stored in a computer-readable storage medium. Based on this understanding, the technical solutions of the embodiments of the present application can be embodied in the form of a software product, which is stored in a storage medium and includes a plurality of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the methods described in the embodiments of the present application. The aforementioned storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM, Read Only Memory), a magnetic disk or an optical disk, and various storage media that can store program codes. Thus, the embodiments of the present application are not limited to any specific hardware and software combination.

[0350] Correspondingly, the embodiments of the present application provide a storage medium having a computer program stored thereon, characterized in that the computer program is executed by a processor to implement the steps of the anisotropy parameter inversion method provided in the above embodiments.

[0351] Example Ten

[0352] The embodiments of the present application provide an anisotropy parameter inversion device including a memory and a processor, wherein the memory has a computer program stored thereon, and the computer program is executed by the processor to configure the processor to execute the program of the anisotropy parameter inversion method stored in the memory to implement the steps of the anisotropy parameter inversion method provided in the above embodiments.

[0353] The descriptions of the display device and the storage medium embodiments above are similar to the descriptions of the method embodiments above, and have similar beneficial effects as the method embodiments. For technical details not disclosed in the computer device and storage medium embodiments of the present application, please refer to the description of the method embodiments of the present application for understanding.

[0354] It should be noted that the description of the storage medium and device embodiments above is similar to the description of the method embodiments above, and has similar beneficial effects as the method embodiments. For technical details not disclosed in the storage medium and device embodiments of the present application, please refer to the description of the method embodiments of the present application for understanding.

[0355] It should be understood that the description of "one embodiment" or "an embodiment" throughout the specification means that the specific features, structures or characteristics related to the embodiment are included in at least one embodiment of the present application. Therefore, "in one embodiment" or "in an embodiment" appearing throughout the specification does not necessarily refer to the same embodiment. In addition, these specific features, structures or characteristics can be combined in one or more embodiments in any suitable manner. It should be understood that the size of the sequence number of each process in various embodiments of the present application does not mean the order of execution, and the execution order of each process should be determined according to its function and inherent logic, and should not constitute any limitation on the implementation process of the embodiments of the present application. The sequence number of the above embodiments of the present application is only for description, not representing the advantages and disadvantages of the embodiments.

[0356] It should be noted that in this document, the terms "comprise", "contain" or any other variant thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or device. Without more limitations, the element defined by the statement "comprises a" does not exclude the presence of additional identical elements in the process, method, article or device including the element.

[0357] In several embodiments provided by the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are only schematic. For example, the division of the units is only a logical function division, and actual implementation can have another division manner, such as: multiple units or components can be combined, or can be integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the displayed or discussed components can be through some interface, indirect coupling or communication connection between devices or units, which can be electrical, mechanical or other forms.

[0358] The units described above as separate components can or can not be physically separated, and the components displayed as units can or can not be physical units; they can be located in one place or distributed on multiple network units; some or all of the units can be selected according to actual needs to achieve the purpose of the embodiment scheme.

[0359] In addition, each function unit in each embodiment of the present application can be integrated in one processing unit, or each unit can be separately as one unit, or two or more units can be integrated in one unit; the integrated unit can be realized in the form of hardware or in the form of hardware plus software function unit.

[0360] Those skilled in the art can understand that all or part of the steps of the above-mentioned method embodiments can be completed by program instruction related hardware, and the foregoing program can be stored in a computer readable storage medium, and the program executes the steps of the above-mentioned method embodiments when executed; and the foregoing storage medium includes mobile storage equipment, read only memory (ROM), magnetic disc or optical disc and various storage program codes.

[0361] Alternatively, when the integrated unit of the present application is realized in the form of a software function module and sold or used as an independent product, it can also be stored in a computer readable storage medium. Based on this understanding, the technical solutions of the embodiments of the present application can be embodied in the form of a software product, which is stored in a storage medium and includes a number of instructions for causing a controller to execute all or part of the methods described in the embodiments of the present application. The foregoing storage medium includes mobile storage equipment, ROM, magnetic disc or optical disc and various storage program codes.

[0362] The above is only an embodiment of the present application, but the protection scope of the present application is not limited thereto, any person skilled in the art can easily think of changes or replacements within the technical range disclosed in the present application, which should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. An anisotropic parameter inversion method, characterized in that, The method comprises the following steps: S1: establishing a shale anisotropic rock physical model of a multi-mineral mixture, a complex pore combination, and an anisotropic clay; S2: performing rock physical testing to obtain rock physical testing data and anisotropic parameters of a rock sample; S3: combining the rock physical testing data to perform rock physical analysis, and obtaining a rock physical model and related parameters suitable for a shale rock structure and a theoretical model physical mechanism; S4: performing pore aspect ratio and clay orientation degree inversion on logging data based on the shale rock physical model of the rock physical analysis; S5: substituting the parameters obtained through inversion into the shale anisotropic rock physical model, and combining the definition of Thomsen anisotropic parameters to obtain anisotropic parameters. The specific method of the porosity aspect ratio and clay orientation degree inversion of the logging data based on the rock physical model of the shale based on the rock physical analysis comprises: combining the mineral components, porosity and density information of the test data, performing forward rock physical model inversion, setting the upper and lower boundaries of the clay orientation index and the change range of the porosity aspect ratio as the search interval by using the grid search method, and calculating the elastic parameters of the shale rock physical model and ; the target function and constraint of the shale rock physical model are constructed by the elastic parameters and ; the maximum likelihood value is obtained as the inversion parameter result by solving the target function; and the target function of the shale rock physical model constructed by the elastic parameters and specifically comprises: （12） wherein, : represents the clay orientation, a parameter describing the degree of alignment of clay minerals; a: represents the pore aspect ratio of brittle minerals in shale; J : objective function; C 33 , C 44 are actual measurements calculated from well logs; C 33model and C 44model are elastic parameters of the shale rock physics model, i.e. corresponding to the values obtained from the rock physics model forward calculation, are functions of the clay orientation and the pore aspect ratio; constraints: clay mineral orientation index and pore aspect ratio with an error within 5%.

2. The method of claim 1, wherein, In the rock physical model, the inversion parameters are a pore aspect ratio α and a clay orientation index.

3. The method of claim 2, wherein, The elastic stiffness matrix of the clay as an anisotropic element is formed in the following manner: （1） In formula (1) is the angle distribution of the mineral arrangement, is the elastic stiffness matrix of the clay mineral arrangement as a random distribution, is the elastic parameter matrix corresponding to the arrangement of the clay mineral particles as a directional arrangement, is the elastic stiffness matrix of the clay; The pore aspect ratio corresponds to rock elastic parameters in the rock physical model.

4. The method of claim 1, wherein, The rock physical testing to obtain rock physical testing data specifically comprises the following steps: mineral components, acoustic velocities, anisotropic parameters, porosities, and pore structure information of core testing data; the specific method for obtaining the acoustic velocities comprises the following steps: sampling shale rocks in a study area, performing anisotropic parameter experiments, and obtaining acoustic velocity information of the rock sample in a bedding vertical direction, a horizontal direction, and a 45º direction; the specific method for obtaining the anisotropic parameter data comprises the following steps: （2） The corresponding stiffness matrix of the anisotropic rock physical equivalent model is as follows: （3） （4） （5） （6） （7） （8） : rock density; V p : P-wave velocity; V sh : shear wave velocity; : P-wave velocity in the direction of 45° to the perpendicular symmetry axis of the bedding plane; : P-wave velocity in the direction of 0º to the perpendicular symmetry axis of the bedding plane; : P-wave velocity in the direction of 90º to the perpendicular symmetry axis of the bedding plane; wherein, （9） : V p Difference in P-wave velocity between vertical and horizontal directions; （10） : V sh Difference in shear wave velocity between vertical and horizontal directions; （11） : Longitudinal wave variation parameter.

5. The method of claim 4, wherein, the anisotropic parameter expression proposed by Thomsen is as follows: The rock physical testing to obtain rock physical testing data specifically further comprises the following steps:

6. An anisotropy parameter inversion apparatus characterized by comprising: a pore aspect ratio of the rock and a clay orientation index of the rock sample; the pore aspect ratio of the rock and the clay orientation index of the rock sample cannot be directly obtained from logging data, and therefore, a pore aspect ratio and clay orientation index inversion method commonly used for core testing data and logging data processing needs to be established. The method comprises the following steps: a rock physical model establishing module, a rock physical testing module, a rock physical analysis module, a pore aspect ratio and clay orientation degree inversion module, and an anisotropic parameter calculation module; the rock physical model establishing module: establishing a shale anisotropic rock physical model of a multi-mineral mixture, a complex pore combination, and an anisotropic clay; the rock physical testing module: performing rock physical testing to obtain rock physical testing data and anisotropic parameters of a rock sample; the rock physical analysis module: combining the rock physical testing data to perform rock physical analysis, and obtaining a rock physical model and related parameters suitable for a shale rock structure and a theoretical model physical mechanism; the pore aspect ratio and clay orientation degree inversion module: performing pore aspect ratio and clay orientation degree inversion on logging data based on the shale rock physical model of the rock physical analysis; the anisotropic parameter calculation module: substituting the parameters obtained through inversion into the shale anisotropic rock physical model, and combining the definition of Thomsen anisotropic parameters to obtain anisotropic parameters. The specific method of the porosity aspect ratio and clay orientation degree inversion of the logging data based on the rock physical model of the shale based on the rock physical analysis comprises: combining the mineral components, porosity and density information of the test data, performing forward rock physical model inversion, setting the upper and lower boundaries of the clay orientation index and the change range of the porosity aspect ratio as the search interval by using the grid search method, and calculating the elastic parameters of the shale rock physical model and ; constructing the objective function and constraint of the shale rock physical model by the elastic parameters and ; solving the objective function to obtain the maximum likelihood value as the inversion parameter result; and the constructing the objective function and constraint of the shale rock physical model by the elastic parameters and specifically comprises: an objective function: （12） wherein, : represents the clay orientation, a parameter describing the degree of alignment of clay minerals; a: represents the pore aspect ratio of brittle minerals in shale; J : objective function; C 33 , C 44 is the actual measurement value calculated from well logging; C 33model and C 44model are the elastic parameters of the shale rock physics model, i.e., the values obtained from the forward calculation of the rock physics model, which are functions of the clay orientation and the pore aspect ratio; constraints: clay mineral orientation index and pore aspect ratio with an error within 5%.

7. An anisotropic parameter inversion device, characterized by, The application also provides a computer program product, comprising a computer program stored in a storage medium, wherein the computer program can be executed by one or more processors, and can be used to implement the anisotropy parameter inversion method according to any one of claims 1 to 5.

8. A storage medium, characterized by The application also provides a computer program product, comprising a computer program stored in a storage medium, wherein the computer program can be executed by one or more processors, and can be used to implement the anisotropy parameter inversion method according to any one of claims 1 to 5.

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