Stratum brittleness earthquake prediction method and device, electronic equipment and storage medium

Abstract

The embodiment of the invention provides a stratum brittleness earthquake prediction method and device, electronic equipment and a storage medium, and the method comprises the steps: carrying out the logging constrained elastic parameter inversion based on the pre-stack earthquake data and logging data of a target region, and obtaining the earthquake elastic parameter of the target region, the earthquake elastic parameters comprise a Young modulus E, a Poisson's ratio v and a Lame coefficient lambda; the seismic elastic parameters of the target area are substituted into a formula, the comprehensive brittleness index BI of the target area is obtained, and a and b are empirical coefficients. In the embodiment of the invention, a new comprehensive brittleness index is constructed, and the comprehensive brittleness index and the mineral brittleness index have relatively high goodness of fit. Besides, the formation brittleness earthquake evaluation method based on the comprehensive brittleness index is combined with testing and logging information analysis, elastic parameters are obtained through pre-stack inversion, the spatial distribution of the comprehensive brittleness index is calculated, and a basis is provided for reliable prediction of the formation brittleness index before drilling.

Description

Technical Field

[0001] This application relates to the field of oil and gas geophysics, specifically to a method, apparatus, electronic device, and storage medium for predicting brittle earthquakes in formations. Background Technology

[0002] The development of unconventional oil and gas reservoirs requires the use of hydraulic fracturing technology to increase oil and gas production per well and achieve economically viable development. Therefore, it is necessary to comprehensively evaluate the brittleness of the formation using geological, logging, and seismic data before drilling.

[0003] Scholars both domestically and internationally use the brittleness index of rocks to characterize the fracturability of unconventional reservoirs, believing that the higher the brittleness index, the easier the rock formation is to fracture. Currently, the evaluation of the brittleness index of unconventional reservoirs is mainly based on the Jarvie mineral empirical brittleness index and the Rickman mechanical brittleness index, but both have certain limitations.

[0004] The difference in mineral content within rocks is the primary reason for the variations in their mechanical properties. By analyzing the influence of mineral content on rock mechanical properties, scholars both domestically and internationally have established various rock brittleness evaluation models based on mineral content. These models determine the rock brittleness value by calculating the proportion of brittle minerals. There is an inherent correlation between the mineral content and the mechanical properties of rocks; therefore, evaluating rock brittleness through mineral composition is highly practical and is often used as a benchmark for other brittleness evaluation methods. However, this method can only be applied when formation cores are obtained or the mineral composition of the formation is obtained through other technical means. Therefore, it can only be used as a post-drilling evaluation method and is difficult to use for regional brittleness index prediction.

[0005] Besides mineral brittleness assessment methods based on the content of brittle minerals in rocks, formation brittleness assessment methods based on rock elastic parameters are used in seismic prediction of formation brittleness. Young's modulus and Poisson's ratio are two very important parameters in rock mechanics, comprehensively reflecting the mineral composition, porosity, permeability, and other properties of rocks. Elastic parameters of the formation are obtained through well logging, seismic analysis, and other methods, from which the brittleness index of the rock is calculated. However, the definitions of these brittleness indices are difficult to correlate well with mineral brittleness indices, and their application effectiveness is questionable.

[0006] It should be noted that the information disclosed in the background section of this application is intended only to enhance the understanding of the general background of this application, and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0007] In view of this, this application provides a method, apparatus, electronic device and storage medium for predicting brittle earthquakes in formations, in order to solve the problem of poor reliability of existing methods for evaluating brittle formations based on seismic elastic parameters.

[0008] In a first aspect, embodiments of this application provide a method for predicting brittle earthquakes in formations based on a comprehensive brittleness index, including:

[0009] Based on the pre-stack seismic data and well logging data of the target area, the elastic parameters constrained by well logging are inverted to obtain the seismic elastic parameters of the target area, which include Young's modulus E, Poisson's ratio v and Lamé coefficient λ.

[0010] Substitute the seismic elastic parameters of the target area into the formula: The comprehensive fragility index BI of the target region is obtained, where a and b are empirical coefficients.

[0011] In one possible implementation, before performing well-logging-constrained elastic parameter inversion based on pre-stack seismic data and well-logging data of the target area to obtain the seismic elastic parameters of the target area, the method further includes:

[0012] Substitute the reference values ​​of the seismic elastic parameters and the initial values ​​of the empirical coefficients a and b into the formula: Obtain a reference value for the Comprehensive Fragility Index (BI);

[0013] The reference values ​​of the comprehensive brittleness index BI are compared with the reference values ​​of the mineral brittleness index to determine the empirical coefficients a and b.

[0014] In one possible implementation, the reference values ​​of the seismic elastic parameters and the initial values ​​of the empirical coefficients a and b are substituted into the formula: Before obtaining a reference value for the Comprehensive Fragility Index (BI), the following steps are also required:

[0015] Based on laboratory test data and / or well logging data, obtain reference values ​​for the seismic elastic parameters and the mineral brittleness index.

[0016] In one possible implementation, the step of performing well-logging-constrained elastic parameter inversion based on pre-stack seismic data and well-logging data of the target area to obtain the seismic elastic parameters of the target area includes:

[0017] Based on pre-stack seismic data and well logging data of the target area, the elastic parameters constrained by well logging are inverted to obtain the data volume of the basic elastic parameters of the target area, which include P-wave velocity, S-wave velocity and density.

[0018] Based on the data volume of the basic elastic parameters of the target area, the seismic elastic parameters of the target area are calculated.

[0019] Secondly, embodiments of this application provide a formation brittle earthquake prediction device based on a comprehensive brittleness index, comprising:

[0020] The seismic elastic parameter determination module is used to perform well-logging-constrained elastic parameter inversion based on pre-stack seismic data and well logging data of the target area to obtain the seismic elastic parameters of the target area, including Young's modulus E, Poisson's ratio v, and Lamé coefficient λ.

[0021] The comprehensive brittleness index determination module is used to substitute the seismic elastic parameters of the target area into the formula: The comprehensive fragility index BI of the target region is obtained, where a and b are empirical coefficients.

[0022] In one possible implementation, an empirical coefficient determination module is also included, for:

[0023] Substitute the reference values ​​of the seismic elastic parameters and the initial values ​​of the empirical coefficients a and b into the formula: Obtain a reference value for the Comprehensive Fragility Index (BI);

[0024] The reference values ​​of the comprehensive brittleness index BI are compared with the reference values ​​of the mineral brittleness index to determine the empirical coefficients a and b.

[0025] In one possible implementation, the empirical coefficient determination module is further configured to:

[0026] Based on laboratory test data and / or well logging data, obtain reference values ​​for the seismic elastic parameters and the mineral brittleness index.

[0027] In one possible implementation, the seismic elastic parameter determination module is specifically used for:

[0028] Based on pre-stack seismic data and well logging data of the target area, the elastic parameters constrained by well logging are inverted to obtain the data volume of the basic elastic parameters of the target area, which include P-wave velocity, S-wave velocity and density.

[0029] Based on the data volume of the basic elastic parameters of the target area, the seismic elastic parameters of the target area are calculated.

[0030] Thirdly, embodiments of this application provide an electronic device, including:

[0031] processor;

[0032] Memory;

[0033] And a computer program, wherein the computer program is stored in the memory, and when the computer program is executed by the processor, implements the method described in any one of the first aspects.

[0034] Fourthly, embodiments of this application provide a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the method described in any one of the first aspects.

[0035] Fifthly, embodiments of this application provide a computer program product, the computer program product including a computer program, which, when executed by a processor, implements the method described in any one of the first aspects.

[0036] In this embodiment, the plane strain Young's modulus from the hydraulic fracturing model is incorporated into the definition of the brittleness index, constructing a new comprehensive brittleness index. This index comprehensively considers both the plane strain Young's modulus, a key variable in the hydraulic fracturing model, and practical applications, resulting in a high degree of agreement between the comprehensive brittleness index and the mineral brittleness index. Furthermore, the seismic assessment method for formation brittleness based on the comprehensive brittleness index, combined with test and well logging data analysis, utilizes pre-stack inversion to obtain elastic parameters and calculates the spatial distribution of the comprehensive brittleness index, providing a foundation for reliable prediction of pre-drilling formation brittleness index. Attached Figure Description

[0037] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0038] Figure 1 A comparison chart of Young's modulus brittleness index and mineral brittleness index provided for embodiments of this application;

[0039] Figure 2 A comparison chart of Poisson's ratio brittleness index and mineral brittleness index provided for embodiments of this application;

[0040] Figure 3 A comparison chart of Rickman brittleness index and mineral brittleness index provided for embodiments of this application;

[0041] Figure 4 A comparison chart of comprehensive brittleness index and mineral brittleness index provided for embodiments of this application;

[0042] Figure 5 A cross-sectional diagram of Young's modulus brittleness index and mineral brittleness index provided for embodiments of this application;

[0043] Figure 6 A cross-sectional diagram of Poisson's ratio brittleness index and mineral brittleness index provided for embodiments of this application;

[0044] Figure 7 A cross-sectional diagram of Rickman brittleness index and mineral brittleness index provided for embodiments of this application;

[0045] Figure 8 A cross-sectional diagram of comprehensive brittleness index and mineral brittleness index provided for embodiments of this application;

[0046] Figure 9 A schematic flowchart of a method for predicting brittle earthquakes in formations based on a comprehensive brittleness index, provided for an embodiment of this application;

[0047] Figure 10 A well profile of density data volume obtained by pre-stack inversion (through well SY1-NY1-JY194-3) provided for an embodiment of this application;

[0048] Figure 11 A well profile (through wells SY1-NY1-JY194-3) of longitudinal wave impedance data volume obtained by pre-stack inversion provided for an embodiment of this application;

[0049] Figure 12 A well profile (through wells SY1-NY1-JY194-3) of longitudinal wave impedance data volume obtained by pre-stack inversion provided for an embodiment of this application;

[0050] Figure 13 A well profile (through wells SY1-NY1-JY194-3) of a comprehensive brittleness index data body calculated from elastic parameters, provided for an embodiment of this application;

[0051] Figure 14 A mean attribute map of the comprehensive brittleness index of a target layer in a study area is provided for embodiments of this application;

[0052] Figure 15 A structural block diagram of a brittle earthquake prediction device based on a comprehensive brittleness index provided in this application embodiment;

[0053] Figure 16 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Detailed Implementation

[0054] To better understand the technical solution of this application, the embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0055] It should be understood that the described embodiments are merely some, not all, of the embodiments in this application. All other embodiments obtained by those skilled in the art based on the embodiments in this application without inventive effort are within the scope of protection of this application.

[0056] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. The singular forms “a,” “the,” and “the” used in the embodiments of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0057] It should be understood that the term "and / or" used in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0058] For the development of unconventional oil and gas reservoirs, hydraulic fracturing technology is essential to achieve economical development. Therefore, scientifically predicting the compressibility of formations before drilling is a crucial technical step to improve development efficiency. Formation brittleness is a key indicator for evaluating formation compressibility. Post-drilling, the rock and mineral composition of different layers can be obtained through well logging or core sampling data, and the formation minerals can be evaluated based on the mineral composition. However, currently, pre-drilling prediction of formation brittleness can only be achieved by inverting elastic parameters from seismic data and calculating the formation brittleness index using these parameters. Several methods exist for defining the brittleness index using elastic parameters, but these methods differ significantly from those using mineral composition, often leading to biases in formation brittleness evaluation. This application aims to propose a new method for brittleness evaluation and prediction, ensuring a high correlation between the brittleness index defined by elastic parameters and the brittleness index defined by mineral composition.

[0059] Specifically, this application embodiment constructs a comprehensive fragility index, which is defined as shown in the following formula.

[0060] Formula 1:

[0061]

[0062] Where BI is the comprehensive brittleness index, E is Young's modulus, v is Poisson's ratio, λ is Lamé coefficient, and a and b are empirical coefficients.

[0063] In other words, the comprehensive brittleness index is determined jointly by Young's modulus, Poisson's ratio, Lamé coefficient, and empirical coefficients. For a given region, empirical coefficients can be determined using test and / or well logging data, based on the principle of consistency with the mineral brittleness index. The first term in Formula 1 is the plane strain Young's modulus. The first term is the quotient of Poisson's ratio multiplied by a constant; the second term is the quotient of Young's modulus and Lamé coefficient multiplied by an experimental constant. This choice is based on the fact that both the KGD model and the PKN model in hydraulic pressure theory are related to the plane strain Young's modulus. Furthermore, practical applications have shown that the quotient of Young's modulus and Lamé coefficient is correlated with the mineral brittleness index. Therefore, the comprehensive brittleness index is a brittleness index that, to some extent, comprehensively considers both fracturing effectiveness and mineral brittleness.

[0064] To explore the effectiveness of the comprehensive brittleness index in Formula 1, data from a shale gas field in southeastern Sichuan were used to compare the newly defined brittleness index with the traditional brittleness index. For ease of comparison, the expressions for the brittleness index used for comparison are given below.

[0065] Formula 2:

[0066]

[0067] Formula 3:

[0068]

[0069] Formula 4:

[0070] BI R =0.5*(BI) E +BI v )

[0071] Formula 2 is the Young's modulus brittleness index, E min E max These represent the maximum and minimum values ​​of Young's modulus of the formation, respectively; Formula 3 is the Poisson's brittleness index, v min v max These represent the minimum and maximum values ​​of Poisson's ratio, respectively; Formula 4 is the Rickman brittleness index.

[0072] In addition, the mineral brittleness index, which serves as a benchmark, is defined as follows.

[0073] Formula 5:

[0074] BI m =(1-V sh )×100

[0075] Among them, V shThis represents the percentage of clay minerals in the solid rock skeleton. It can be understood that Formula 5 represents the percentage of brittle minerals in the solid rock skeleton.

[0076] Using data from well JY194-3 in a gas field, the brittleness index defined by formulas one through four was calculated, and these indices were compared with the mineral brittleness index calculated using formula five. Figures 1-4 ).from Figures 1-4 It can be seen that the newly defined comprehensive brittleness index is close to the mineral brittleness index.

[0077] Furthermore, the brittleness indices calculated using Formulas 1 to 4 are intersected with the mineral brittleness index. Figures 5-8 ).from Figures 5-8 It can be seen that the composite brittleness index has a higher correlation with the mineral brittleness index. This indicates that the composite brittleness index and the mineral brittleness index have a high degree of agreement and can be used to evaluate the compressibility of formations. Furthermore, the elastic parameters in their definitions are obtained through seismic elastic parameter inversion techniques.

[0078] Based on the above-mentioned calculation model of the comprehensive brittleness index, this application embodiment also provides a method for predicting brittle earthquakes in formations based on the comprehensive brittleness index.

[0079] See Figure 9 This is a schematic diagram illustrating a method for predicting brittle earthquakes in formations based on a comprehensive brittleness index, provided in an embodiment of this application. Figure 9 As shown, it mainly includes the following steps.

[0080] Step S901: Based on the pre-stack seismic data and well logging data of the target area, perform well logging-constrained elastic parameter inversion to obtain the seismic elastic parameters of the target area, including Young's modulus E, Poisson's ratio v, and Lamé coefficient λ.

[0081] Specifically, based on pre-stack seismic data and well logging data of the target area, well logging-constrained elastic parameter inversion is performed to obtain the data volume of basic elastic parameters of the target area, including P-wave velocity, S-wave velocity and density; based on the data volume of basic elastic parameters of the target area, the seismic elastic parameters of the target area are calculated.

[0082] Step S902: Substitute the seismic elastic parameters of the target area into the calculation formula of the comprehensive brittleness index to obtain the comprehensive brittleness index BI of the target area.

[0083] Understandably, before performing formation brittleness earthquake prediction based on the comprehensive brittleness index, it is necessary to determine the empirical coefficients a and b in the calculation model of the comprehensive brittleness index. Specifically, reference values ​​for seismic elastic parameters and mineral brittleness index can be obtained based on laboratory test data and / or well logging data. Substituting the reference values ​​for seismic elastic parameters and the initial values ​​of empirical coefficients a and b into the calculation formula of the comprehensive brittleness index (Formula 1), a reference value for the comprehensive brittleness index BI is obtained; the reference value for the comprehensive brittleness index BI is then compared with the reference value for the mineral brittleness index to determine the empirical coefficients a and b.

[0084] Substituting the calculated Young's modulus E, Poisson's ratio v, Lamé coefficient λ, and empirical coefficients a and b into the formula for calculating the comprehensive brittleness index, the comprehensive brittleness index BI of the target region is obtained.

[0085] In this embodiment, the plane strain Young's modulus from the hydraulic fracturing model is incorporated into the definition of the brittleness index, constructing a new comprehensive brittleness index. This index comprehensively considers both the plane strain Young's modulus, a key variable in the hydraulic fracturing model, and practical applications, resulting in a high degree of agreement between the comprehensive brittleness index and the mineral brittleness index. Furthermore, the seismic assessment method for formation brittleness based on the comprehensive brittleness index, combined with test and well logging data analysis, utilizes pre-stack inversion to obtain elastic parameters and calculates the spatial distribution of the comprehensive brittleness index, providing a foundation for reliable prediction of pre-drilling formation brittleness index.

[0086] Analysis of shale gas reservoirs in a shale gas field in southeastern Sichuan revealed that the mineral brittleness index of shale formations can be well characterized by the comprehensive brittleness index of neotectonics. Furthermore, the comprehensive brittleness index can be derived from elastic parameters obtained through pre-stack inversion. Therefore, the comprehensive brittleness index can be used for pre-drilling formation brittleness evaluation, and this has yielded excellent results.

[0087] To facilitate understanding, the following uses a shale gas field as an example to systematically explain how to perform seismic prediction based on the comprehensive brittleness index.

[0088] Firstly, through experiments, under the conditions of a = 0.165 and b = 10, the comprehensive brittleness index is closest to the mineral brittleness index (calculation results are shown below). Figure 4 (As shown); secondly, the basic elastic parameters of the strata are obtained using pre-stack inversion, such as... Figures 10-12 As shown; finally, using the conversion formula between elastic parameters, E, v, and λ are calculated, and finally, the comprehensive brittleness index is calculated using Formula 1, as shown. Figure 13 As shown. The average value of the comprehensive brittleness index within the target layer is extracted along the target layer of the work area, resulting in the planar distribution of the comprehensive brittleness index of the target layer, as shown. Figure 14 As shown. In Figure 14Among them, wells JY194-3, JY201-1, JY10, and JY10-10 are located in the zone with a high brittleness index, and the fracturing effect during production is also good, which confirms the effectiveness of the prediction.

[0089] Corresponding to the above embodiments, this application also provides a brittle earthquake prediction device based on a comprehensive brittleness index.

[0090] See Figure 15 This is a structural block diagram of a brittle earthquake prediction device based on a comprehensive brittleness index, provided in an embodiment of this application. Figure 15 As shown, it mainly includes the following modules.

[0091] The seismic elastic parameter determination module 1501 is used to perform well-logging constrained elastic parameter inversion based on pre-stack seismic data and well logging data of the target area to obtain the seismic elastic parameters of the target area, wherein the seismic elastic parameters include Young's modulus E, Poisson's ratio v and Lamé coefficient λ.

[0092] The comprehensive brittleness index determination module 1502 is used to substitute the seismic elastic parameters of the target area into the formula: The comprehensive fragility index BI of the target region is obtained, where a and b are empirical coefficients.

[0093] In one possible implementation, an empirical coefficient determination module is also included, used to: substitute the reference values ​​of the seismic elastic parameters and the initial values ​​of the empirical coefficients a and b into the formula: Obtain a reference value for the comprehensive brittleness index BI; compare the reference value of the comprehensive brittleness index BI with the reference value of the mineral brittleness index to determine the empirical coefficients a and b.

[0094] In one possible implementation, the empirical coefficient determination module is further configured to: obtain reference values ​​for the seismic elastic parameters and the mineral brittleness index based on laboratory test data and / or well logging data.

[0095] In one possible implementation, the seismic elastic parameter determination module is specifically used for: performing well-logging-constrained elastic parameter inversion based on pre-stack seismic data and well logging data of the target area to obtain a data volume of basic elastic parameters of the target area, the basic elastic parameters including P-wave velocity, S-wave velocity and density; and calculating the seismic elastic parameters of the target area based on the data volume of basic elastic parameters of the target area.

[0096] In this embodiment, the plane strain Young's modulus from the hydraulic fracturing model is incorporated into the definition of the brittleness index, constructing a new comprehensive brittleness index. This index comprehensively considers both the plane strain Young's modulus, a key variable in the hydraulic fracturing model, and practical applications, resulting in a high degree of agreement between the comprehensive brittleness index and the mineral brittleness index. Furthermore, the seismic assessment method for formation brittleness based on the comprehensive brittleness index, combined with test and well logging data analysis, utilizes pre-stack inversion to obtain elastic parameters and calculates the spatial distribution of the comprehensive brittleness index, providing a foundation for reliable prediction of pre-drilling formation brittleness index.

[0097] It should be noted that the specific content involved in the embodiments of this application can be found in the description of the above method embodiments, and will not be repeated here for the sake of brevity.

[0098] Corresponding to the above embodiments, this application also provides an electronic device.

[0099] See Figure 16 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Figure 16 As shown, the electronic device 1600 may include a processor 1601, a memory 1602, and a communication unit 1603. These components communicate via one or more buses. Those skilled in the art will understand that the electronic device structure shown in the figure does not constitute a limitation on the embodiments of this application. It may be a bus topology or a star topology, and may include more or fewer components than shown, or combine certain components, or have different component arrangements.

[0100] The communication unit 1603 is used to establish a communication channel, thereby enabling the electronic device to communicate with other devices.

[0101] Processor 1601 serves as the control center of the electronic device, connecting various parts of the device via various interfaces and lines. It executes software programs and / or modules stored in memory 1602, and calls data stored in memory to perform various functions and / or process data. The processor can be composed of integrated circuits (ICs), such as a single packaged IC or multiple packaged ICs with the same or different functions connected together. For example, processor 1601 may consist only of a central processing unit (CPU). In this embodiment, the CPU may have a single processing core or include multiple processing cores.

[0102] Memory 1602 is used to store the execution instructions of processor 1601. Memory 1602 can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic storage, flash memory, magnetic disk or optical disk.

[0103] When the execution instructions in memory 1602 are executed by processor 1601, the electronic device 1600 is able to perform some or all of the steps in the above method embodiments.

[0104] Corresponding to the above embodiments, this application also provides a computer-readable storage medium, wherein the computer-readable storage medium may store a computer program, and when the computer program is executed by a processor, it may implement some or all of the steps in the above method embodiments.

[0105] In specific implementations, the computer-readable storage medium can be a magnetic disk, an optical disk, a read-only memory (ROM), or a random access memory (RAM), etc.

[0106] Corresponding to the above embodiments, this application also provides a computer program product, which includes a computer program that, when executed by a processor, can implement some or all of the steps in the above method embodiments.

[0107] In this application embodiment, "at least one" refers to one or more, and "more than one" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent the existence of A alone, the simultaneous existence of A and B, or the existence of B alone. A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one of the following" and similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, and c can represent: a, b, c, ab, ac, bc, or abc, where a, b, and c can be single or multiple.

[0108] Those skilled in the art will recognize that the units and algorithm steps described in the embodiments disclosed herein can be implemented using electronic hardware, computer software, or a combination of electronic hardware and software. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0109] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0110] In the several embodiments provided in this application, any function, if implemented as a software functional unit and sold or used as an independent product, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0111] The above description is merely a specific embodiment of this application. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the protection scope of this application. The protection scope of this application should be determined by the protection scope of the claims.

Claims

1. A method for predicting brittle earthquakes in formations based on a comprehensive brittleness index, characterized in that, include: Based on the pre-stack seismic data and well logging data of the target area, the elastic parameters constrained by well logging are inverted to obtain the seismic elastic parameters of the target area, which include Young's modulus E, Poisson's ratio v and Lamé coefficient λ. Substitute the seismic elastic parameters of the target area into the formula: The comprehensive fragility index BI of the target region is obtained, where a and b are empirical coefficients.

2. The method according to claim 1, characterized in that, Before performing well-logging-constrained elastic parameter inversion based on pre-stack seismic data and well-logging data of the target area to obtain the seismic elastic parameters of the target area, the method further includes: Substitute the reference values ​​of the seismic elastic parameters and the initial values ​​of the empirical coefficients a and b into the formula: Obtain a reference value for the Comprehensive Fragility Index (BI); The reference values ​​of the comprehensive brittleness index BI are compared with the reference values ​​of the mineral brittleness index to determine the empirical coefficients a and b.

3. The method according to claim 2, characterized in that, Substituting the reference values ​​of the seismic elastic parameters and the initial values ​​of the empirical coefficients a and b into the formula: Before obtaining a reference value for the Comprehensive Fragility Index (BI), the following steps are also required: Based on laboratory test data and / or well logging data, obtain reference values ​​for the seismic elastic parameters and the mineral brittleness index.

4. The method according to claim 1, characterized in that, The method of performing well-logging-constrained elastic parameter inversion based on pre-stack seismic data and well logging data of the target area to obtain the seismic elastic parameters of the target area includes: Based on pre-stack seismic data and well logging data of the target area, the elastic parameters constrained by well logging are inverted to obtain the data volume of the basic elastic parameters of the target area, which include P-wave velocity, S-wave velocity and density. Based on the data volume of the basic elastic parameters of the target area, the seismic elastic parameters of the target area are calculated.

5. A formation brittleness earthquake prediction device based on a comprehensive brittleness index, characterized in that, include: The seismic elastic parameter determination module is used to perform well-logging-constrained elastic parameter inversion based on pre-stack seismic data and well logging data of the target area to obtain the seismic elastic parameters of the target area, including Young's modulus E, Poisson's ratio v, and Lamé coefficient λ. The comprehensive brittleness index determination module is used to substitute the seismic elastic parameters of the target area into the formula: The comprehensive fragility index BI of the target region is obtained, where a and b are empirical coefficients.

6. The apparatus according to claim 5, characterized in that, It also includes an empirical coefficient determination module, used for: Substitute the reference values ​​of the seismic elastic parameters and the initial values ​​of the empirical coefficients a and b into the formula: Obtain a reference value for the Comprehensive Fragility Index (BI); The reference values ​​of the comprehensive brittleness index BI are compared with the reference values ​​of the mineral brittleness index to determine the empirical coefficients a and b.

7. The apparatus according to claim 6, characterized in that, The empirical coefficient determination module is also used for: Based on laboratory test data and / or well logging data, obtain reference values ​​for the seismic elastic parameters and the mineral brittleness index.

8. The apparatus according to claim 5, characterized in that, The seismic elastic parameter determination module is specifically used for: Based on pre-stack seismic data and well logging data of the target area, the elastic parameters constrained by well logging are inverted to obtain the data volume of the basic elastic parameters of the target area, which include P-wave velocity, S-wave velocity and density. Based on the data volume of the basic elastic parameters of the target area, the seismic elastic parameters of the target area are calculated.

9. An electronic device, characterized in that, include: processor; Memory; And a computer program, wherein the computer program is stored in the memory, and when executed by the processor, the computer program implements the method of any one of claims 1-4.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the method described in any one of claims 1-4.

11. A computer program product, characterized in that, The computer program product includes a computer program that, when executed by a processor, implements the method described in any one of claims 1-4.

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