Seismic evaluation method and apparatus for fault stability

Abstract

The embodiments of the present invention belong to the technical field of petroleum and natural gas seismic exploration. Provided are a seismic evaluation method and apparatus for fault stability. The method comprises: acquiring basic seismic material of a drilling section; performing fracture interpretation on the basis of actual drilling data, and identifying a fracture development position of the drilling section; on the basis of seismic data, extracting seismic attributes capable of being used for predicting a fracture; determining a sensitive attribute body, a quantitative fracture characterization result, a crustal stress prediction result and a crustal stress direction prediction result; on the basis of a Mohr-Coulomb theory and on the basis of the quantitative fracture characterization result combined with the crustal stress prediction result and the crustal stress direction prediction result, calculating the shear stress and effective normal stress of a fracture surface, and obtaining a fracture stability prediction plane map on the basis of the shear stress and effective normal stress of the fracture surface. In the method, the shear stress and effective normal stress of a fracture surface is calculated by using seismic fracture and crustal stress field prediction results, so as to evaluate a stable state of the fracture surface, and fault stability can be quantitatively evaluated.

Description

Seismic assessment method and device for fault stability Technical Field

[0001] The present invention relates to the technical field of oil and gas seismic exploration, and in particular to a seismic evaluation method for fault stability, a seismic evaluation device for fault stability, a machine-readable storage medium, and a processor. Background Art

[0002] In unconventional exploration and development, casing deformation is a major factor restricting scale-effective development. In current shale gas exploration and development, casing deformation is common during the drilling and fracturing stages. There are many factors that cause casing deformation, including temperature, asymmetric fracturing, cementing quality, and fault slip. Current research on casing deformation caused by fault slip focuses on single-wellbore analysis, including cementing stages, casing loads, cement sheaths, and geostress analysis. By establishing a multi-stage fracturing numerical model, the geostress changes near the wellbore are calculated. There is no literature that mentions the study of the mechanical stability of the fracture itself. The distribution of underground stress, the spatial angle between the maximum principal stress and the fracture surface, and the relationship between the friction and shear stress of the fracture surface are all important factors affecting the mechanical stability of the fracture.

[0003] Existing geophysical prediction methods include: (1) prediction of faults of different scales, using post-stack data to extract coherence, curvature, texture, symmetry, ant body, maximum likelihood attributes, etc. for qualitative prediction; (2) seismic prediction of ground stress, using pre-stack inversion of longitudinal wave impedance, shear wave impedance, density and longitudinal and shear wave velocity ratio, and then calculating rock mechanical parameters such as Young's modulus, Poisson's ratio, brittleness index, etc.

[0004] However, existing geophysical prediction methods are unable to quantitatively assess the stability of faults, making it difficult to guide well deployment and avoid drilling risks.

[0005] Summary of the Invention

[0006] The purpose of the embodiments of the present invention is to provide a seismic assessment method and apparatus for fault stability, which can quantitatively assess the stability of the fault to guide well site deployment and avoid drilling risks.

[0007] In order to achieve the above object, the present invention provides a first aspect of a seismic assessment method for fault stability, the method comprising:

[0008] Acquire basic seismic data of the drilling section; wherein the basic seismic data of the drilling section includes seismic data and actual drilling data;

[0009] Performing fracture interpretation based on the actual drilling data to identify fracture development locations in the drilling section;

[0010] extracting seismic attributes capable of predicting rupture based on the seismic data;

[0011] Calibrate the fracture development position of the drilling section and the seismic attributes to determine a sensitive attribute body, and determine a fracture quantitative characterization result based on the sensitive attribute body;

[0012] Performing elastic parameter inversion based on the seismic data to obtain an elastic parameter volume, and determining a rock mechanics parameter volume based on the elastic parameter volume;

[0013] Determining a ground stress prediction result based on the elastic parameter body and the rock mechanics parameter body;

[0014] Based on thin plate theory and using rock mechanics parameter bodies, geological, mechanical and mathematical models are established, and three-dimensional finite element difference simulation methods are used to determine the prediction results of the ground stress direction;

[0015] Based on the Mohr-Coulomb theory and the results of quantitative characterization of the fracture, combined with the ground stress prediction results and the ground stress direction prediction results, the fracture surface shear stress and effective normal stress are calculated, and the fracture stability prediction plane diagram is obtained based on the fracture surface shear stress and effective normal stress.

[0016] Optionally, performing fracture interpretation based on the actual drilling data to identify fracture development locations in the drilling section includes:

[0017] The location of fault development in the drilling section was interpreted through the actual drilling engineering recovery map, FMI imaging logging data, conventional logging data, horizontal section logging data and microseismic monitoring data.

[0018] Optionally, the seismic data includes time-domain prestack migration gathers; and performing elastic parameter inversion based on the seismic data to obtain an elastic parameter volume includes:

[0019] The elastic parameter inversion is completed using the time domain prestack migration gathers to obtain the elastic parameter volume.

[0020] Optionally, the in-situ stress prediction result includes overlying formation pressure; and the method includes:

[0021] Based on the elastic parameter body and the rock mechanics parameter body, a normal compaction curve of density is calculated using a seismic travel time equation;

[0022] Create a density curve using the normal compaction curve of density and the actual measured density curve;

[0023] The overlying formation pressure is calculated using the integral of the density curve.

[0024] Optionally, the geostress prediction result further includes formation pore pressure; and the method includes:

[0025] The formation pore pressure is calculated based on the elastic parameter body and the rock mechanics parameter body using Eaton's empirical formula.

[0026] Optionally, the geostress prediction result further includes horizontal principal stress; and the method includes:

[0027] Based on the elastic parameter body and the rock mechanics parameter body, the horizontal principal stress is calculated using the Huang model.

[0028] Optionally, a fracture stability prediction plan is obtained based on the fracture plane shear stress and effective normal stress, including:

[0029] The shear stress and the effective normal stress of the fracture surface are compared to obtain a comparison result; and a fracture stability prediction plane diagram is drawn according to the comparison result.

[0030] A second aspect of the present invention provides a seismic assessment device for fault stability, the device comprising:

[0031] A basic data acquisition module is used to acquire basic seismic data of the drilling section; wherein the basic seismic data of the drilling section includes seismic data and actual drilling data;

[0032] A fracture interpretation module, configured to perform fracture interpretation based on the actual drilling data and identify fracture development locations in the drilling section;

[0033] A seismic attribute extraction module, configured to extract seismic attributes capable of predicting fractures based on the seismic data;

[0034] a calibration module, configured to calibrate the fracture development position of the drilling section and the seismic attributes, determine a sensitive attribute body, and determine a fracture quantitative characterization result based on the sensitive attribute body;

[0035] an inversion module, configured to perform elastic parameter inversion based on the seismic data, obtain an elastic parameter volume, and determine a rock mechanics parameter volume based on the elastic parameter volume;

[0036] a geostress prediction module, configured to determine a geostress prediction result based on the elastic parameter body and the rock mechanics parameter body;

[0037] The in-situ stress direction prediction module is used to establish geological, mechanical, and mathematical models based on thin plate theory and rock mechanics parameter bodies, and to determine the in-situ stress direction prediction results using the three-dimensional finite element difference simulation method;

[0038] The fracture stability prediction module is used to calculate the fracture surface shear stress and effective normal stress based on the Mohr-Coulomb theory and the results of fracture quantitative characterization, combined with the ground stress prediction results and the ground stress direction prediction results, and obtain the fracture stability prediction plane diagram based on the fracture surface shear stress and effective normal stress.

[0039] A third aspect of the present invention provides a processor configured to execute the above-mentioned seismic assessment method of fault stability.

[0040] A fourth aspect of the present invention provides a machine-readable storage medium having instructions stored thereon, which, when executed by a processor, configure the processor to execute the above-mentioned seismic assessment method for fault stability.

[0041] Compared with the prior art, the above technical solution of the present invention has the following beneficial effects:

[0042] The present invention provides a seismic assessment method and device for fault stability. The method uses the results of earthquake fracture and ground stress field prediction to calculate the shear stress and effective normal stress of the fracture surface to evaluate the stability of the fracture surface. The method can quantitatively assess the stability of the fault to guide well site deployment and avoid drilling risks.

[0043] Other features and advantages of the embodiments of the present invention will be described in detail in the subsequent detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The accompanying drawings are used to provide a further understanding of the embodiments of the present invention and constitute a part of the specification. Together with the following detailed description, they are used to explain the embodiments of the present invention, but do not constitute a limitation of the embodiments of the present invention. In the accompanying drawings:

[0045] The accompanying drawings are used to provide a further understanding of the embodiments of the present invention and constitute a part of the specification. Together with the following detailed description, they are used to explain the embodiments of the present invention, but do not constitute a limitation of the embodiments of the present invention. In the accompanying drawings:

[0046] FIG1 schematically shows an overall flow chart of a seismic assessment method for fault stability according to an embodiment of the present invention;

[0047] FIG2 schematically shows a specific flow chart of a method for seismic assessment of fault stability according to an embodiment of the present invention;

[0048] FIG3 schematically shows a schematic diagram of a plane distribution of overburden formation pressure prediction according to an embodiment of the present invention;

[0049] FIG4 schematically shows a schematic diagram of the horizontal principal stress difference superimposed on the maximum horizontal principal stress direction according to an embodiment of the present invention;

[0050] FIG5 schematically shows a fracture space channel and a quantitative characterization diagram according to an embodiment of the present invention;

[0051] FIG6 schematically shows a plan view of fracture-slip risk prediction according to an embodiment of the present invention;

[0052] FIG7 schematically shows a structural block diagram of a seismic assessment device for fault stability according to an embodiment of the present invention. DETAILED DESCRIPTION

[0053] To make the purpose, technical solutions and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. It should be understood that the specific implementation methods described herein are only used to illustrate and explain the embodiments of the present invention and are not used to limit the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0054] FIG1 schematically illustrates an overall flow chart of a seismic assessment method for fault stability according to an embodiment of the present invention. FIG2 schematically illustrates a specific flow chart of a seismic assessment method for fault stability according to an embodiment of the present invention. As shown in FIG1-2 , in one embodiment of the present invention, a seismic assessment method for fault stability is provided to quantitatively assess the stability of a fault and solve the engineering prediction problem of avoiding high-slip risk fractures during drilling, comprising the following steps:

[0055] Step 110: Acquire basic seismic data of the drilling section; wherein the basic seismic data of the drilling section includes seismic data and actual drilling data.

[0056] Specifically, it is first necessary to obtain basic data for seismic assessment of fracture mechanics stability. Seismic data include time-domain prestack migration gathers and time-domain full-stack migration data. Actual drilling data include drilling coordinates, drilling layers, drilling displays, drilling well trajectories, logging data from the surface to the underground target layer (including but not limited to P-wave, density, S-wave, natural gamma, total hydrocarbon curve, gamma while drilling, etc.), element logging curves, in-situ stress data (maximum horizontal principal stress and direction, minimum horizontal principal stress, overburden pressure, pore pressure, etc.), FMI imaging logging data, actual drilling engineering stratum recovery profiles, and microseismic monitoring data.

[0057] Step 120: perform fracture interpretation based on the actual drilling data to identify fracture development locations in the drilling section.

[0058] Specifically, the fracture development locations in the drilling section (including the fracture development locations in the vertical well section and the horizontal well section) are identified through actual drilling engineering formation recovery profiles, FMI imaging logging data, conventional logging data (natural gamma, deep and shallow resistivity, acoustic time difference, density and neutron), horizontal section logging (full hydrocarbon curve, gamma while drilling), and microseismic monitoring results.

[0059] Step 130: extracting seismic attributes capable of predicting fractures based on the seismic data.

[0060] Specifically, based on the time-domain prestack migration gather, the drilling trajectory in the depth domain is converted to the time domain by extracting seismic wavelets and producing synthetic seismic records, which facilitates matching with the time-domain full-stack migration data volume. In addition, faults with more than half a phase dislocation are manually interpreted on the time-domain seismic data. A variety of seismic attributes that can currently predict faults are extracted, including structural attributes (similarity, curvature, texture, maximum likelihood body, etc.), geometric attributes (body curvature, dip, azimuth, etc.), instantaneous attributes (amplitude, frequency, phase, envelope, energy, ant body anomalies, etc.), and artificial intelligence-based fault prediction.

[0061] Step 140 : calibrate the fracture development position in the drilling section and the seismic attributes to determine a sensitive attribute body, and determine a fracture quantitative characterization result based on the sensitive attribute body.

[0062] Figure 5 schematically shows a schematic diagram of a fracture space channel and quantitative characterization according to an embodiment of the present invention. Specifically, the fracture development position of the drilling section is calibrated with the seismic attributes, and 3-4 sensitive attribute bodies (usually including but not limited to body curvature, ant body, artificial intelligence fracture prediction) that may be fractured are selected. The fracture prediction attribute body (dip, azimuth, similarity or artificial intelligence fracture prediction or curvature) is selected, and the attribute values ​​are extracted along the main target layer segment. The extracted attribute values ​​(dip, similarity or curvature) are intersected, and points with high dip, low similarity or high body curvature values ​​are filtered out. The collection of these points in space is the fracture channel. The positions and characteristic values ​​(dip, inclination) of these points are determined, and each fracture piece in the fracture channel can be simulated based on these values, as shown in Figure 5.

[0063] Step 150: Perform elastic parameter inversion based on the seismic data to obtain an elastic parameter volume, and determine a rock mechanics parameter volume based on the elastic parameter volume.

[0064] Specifically, the elastic parameter inversion is completed using the time domain prestack migration gathers to obtain elastic parameter bodies such as longitudinal waves, shear waves, and density. Based on these elastic parameter bodies, rock mechanics parameter bodies such as Young's modulus, Poisson's ratio, and Lame constant are calculated.

[0065] Step 160: Determine a ground stress prediction result based on the elastic parameter body and the rock mechanics parameter body.

[0066] Figure 3 schematically shows a schematic diagram of the planar distribution of overburden formation pressure prediction according to an embodiment of the present invention. Specifically, the above-mentioned elastic parameters and rock mechanics parameter bodies are used, and the relationship between porosity and depth (based on the Athy equation of seismic travel time) is used to calculate the normal compaction curve of the acoustic wave and density curve; the resistivity or gamma curve is used to calculate the mudstone indicator trend line and the clay content; for overpressure formations, a normal density curve is created using the normal compaction curve of density and the actual measured density curve; the overburden formation pressure is calculated using the density curve integral; the formation pore pressure is calculated using Eaton's empirical formula; and the horizontal principal stress is calculated using the Huang model. Based on the above process, the overburden formation pressure body, the formation pore pressure body and the horizontal stress body can be obtained.

[0067] Step 170 , based on thin plate theory and using rock mechanics parameter bodies, geological, mechanical and mathematical models are established, and a three-dimensional finite element difference simulation method is used to determine the prediction result of the ground stress direction.

[0068] Figure 4 schematically illustrates a diagram of the horizontal principal stress difference superimposed on the maximum horizontal principal stress direction according to an embodiment of the present invention. Specifically, based primarily on thin plate theory and utilizing a rock mechanics parameter body, geological, mechanical, and mathematical models were established. The maximum horizontal principal stress direction was simulated using a three-dimensional finite element differential simulation method. The results were then calibrated against the measured maximum principal stress direction. Based on the calibration results, the model parameters were continuously optimized and adjusted until the agreement with the actual maximum principal stress direction during drilling was greater than 70%, as shown in Figure 4.

[0069] Step 180 , based on the Mohr-Coulomb theory, on the basis of the quantitative characterization results of the fracture, combined with the ground stress prediction results and the ground stress direction prediction results, calculate the fracture surface shear stress and effective normal stress, and obtain a fracture stability prediction plane diagram based on the fracture surface shear stress and effective normal stress.

[0070] Figure 6 schematically illustrates a fracture slip risk prediction plan according to an embodiment of the present invention. Specifically, guided by the Mohr-Coulomb criterion (a classical mechanical theory of fracture surface slip), the results obtained from the above process, namely the maximum horizontal principal stress and its direction, the minimum horizontal principal stress, and the fracture surface inclination, are used to calculate the fracture surface shear stress and effective normal stress distribution plans. By comparing the shear stress with the friction force (effective normal stress), a fracture stability prediction plan is obtained, as shown in Figure 6.

[0071] Fig. 2 is a schematic flow diagram of a method for seismic assessment of fault stability in one embodiment. It should be understood that, although the various steps in the flow diagram of Fig. 2 are shown in sequence as indicated by the arrows, these steps are not necessarily performed in sequence in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order restriction for the execution of these steps, and these steps can be performed in other orders. Moreover, at least a portion of the steps in Fig. 2 may include a plurality of sub-steps or a plurality of stages, and these sub-steps or stages are not necessarily performed at the same time, but can be performed at different times, and the execution order of these sub-steps or stages is not necessarily performed in sequence, but can be performed in turn or alternately with at least a portion of other steps or sub-steps or stages of other steps.

[0072] The method described in the embodiment of the present invention borrows the mature seismic inversion technology, seismic attribute extraction technology, rock mechanics Eaton formation pore pressure empirical formula, three-dimensional finite element difference simulation method, ground stress calculation based on Huang's model, and the classical theory of fracture surface sliding dynamics Mohr-Coulomb criterion in the field of seismic exploration, and proposes an original technology for fracture surface seismic assessment. Mohr-Coulomb is often used to assess the sliding of wellbore fracture surfaces, and regionally, only the sliding risk prediction can be performed for the drilling location. The embodiment of the present invention takes advantage of the continuous spatial distribution of seismic data, and can perform sliding risk analysis and prediction on regional fracture surfaces, perform sliding risk assessment on different locations of the fracture surface, and perform risk assessment on different stress locations. Compared with the later method of using digital random modeling to perform fracture risk assessment, the data between wellbores all come from deterministic seismic data, rather than the mathematical interpolation method of random space modeling, so the amount of data calculation is small, and the prediction accuracy and stability are higher.

[0073] The method described in the embodiments of the present invention is currently being effectively utilized in deep shale gas exploration and development in the southern Sichuan Basin. This method, used to assess fracture stability, correlates well with actual drilling results and is currently supporting a pilot program for optimizing deep shale gas in the Luzhou area. This has resulted in a 16% increase in well locations deployed in the Lu-203 well block and adjustments to drilling plans for over 20 wells currently in development. This has increased underground resource utilization, effectively guided production, significantly reduced the probability of casing changes, saved drilling time, and improved economic efficiency.

[0074] In one embodiment, as shown in FIG7 , a seismic assessment device for fault stability is provided, the device comprising:

[0075] Basic data acquisition module 210, used to acquire basic seismic data of the drilling section; wherein the basic seismic data of the drilling section includes seismic data and actual drilling data;

[0076] A fracture interpretation module 220 is configured to perform fracture interpretation based on the actual drilling data and identify fracture development locations in the drilling section;

[0077] A seismic attribute extraction module 230 is configured to extract seismic attributes capable of predicting fractures based on the seismic data;

[0078] A calibration module 240 is used to calibrate the fracture development position of the drilling section and the seismic attributes, determine a sensitive attribute body, and determine a fracture quantitative characterization result based on the sensitive attribute body;

[0079] an inversion module 250 for performing elastic parameter inversion based on the seismic data to obtain an elastic parameter volume, and determining a rock mechanics parameter volume based on the elastic parameter volume;

[0080] A geostress prediction module 260 is configured to determine a geostress prediction result based on the elastic parameter body and the rock mechanics parameter body;

[0081] The in-situ stress direction prediction module 270 is used to establish geological, mechanical, and mathematical models based on thin plate theory and using rock mechanics parameter bodies, and to determine the in-situ stress direction prediction results using a three-dimensional finite element difference simulation method;

[0082] The fracture stability prediction module 280 is used to calculate the fracture surface shear stress and effective normal stress based on the Mohr-Coulomb theory and the fracture quantitative characterization results, combined with the ground stress prediction results and the ground stress direction prediction results, and obtain the fracture stability prediction plane diagram based on the fracture surface shear stress and effective normal stress.

[0083] The seismic assessment device for fault stability includes a processor and a memory. The above-mentioned basic data acquisition module, fracture interpretation module, seismic attribute extraction module, calibration module, inversion module, ground stress prediction module, ground stress direction prediction module and fracture stability prediction module are all stored in the memory as program units, and the processor executes the above-mentioned program units stored in the memory to realize corresponding functions.

[0084] The processor includes a core, which retrieves the corresponding program unit from the memory. One or more cores can be provided, and the seismic assessment method for fault stability can be implemented by adjusting the core parameters.

[0085] The memory may include non-permanent memory in a computer-readable medium, random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM, and the memory includes at least one memory chip.

[0086] An embodiment of the present invention provides a storage medium having a program stored thereon, which implements the seismic assessment method of fault stability when executed by a processor.

[0087] An embodiment of the present invention provides a processor, which is used to run a program, wherein the program executes the seismic assessment method of fault stability when running.

[0088] An embodiment of the present invention provides a device, comprising a processor, a memory, and a program stored in the memory and executable on the processor. When the processor executes the program, the following steps are performed:

[0089] Step 110: Acquire basic seismic data of the drilling section; wherein the basic seismic data of the drilling section includes seismic data and actual drilling data.

[0090] Step 120: perform fracture interpretation based on the actual drilling data to identify fracture development locations in the drilling section.

[0091] Step 130: extracting seismic attributes capable of predicting fractures based on the seismic data.

[0092] Step 140 : calibrate the fracture development position in the drilling section and the seismic attributes to determine a sensitive attribute body, and determine a fracture quantitative characterization result based on the sensitive attribute body.

[0093] Step 150: Perform elastic parameter inversion based on the seismic data to obtain an elastic parameter volume, and determine a rock mechanics parameter volume based on the elastic parameter volume.

[0094] Step 160: Determine a ground stress prediction result based on the elastic parameter body and the rock mechanics parameter body.

[0095] Step 170 , based on thin plate theory and using rock mechanics parameter bodies, geological, mechanical and mathematical models are established, and a three-dimensional finite element difference simulation method is used to determine the prediction result of the ground stress direction.

[0096] Step 180 , based on the Mohr-Coulomb theory, on the basis of the quantitative characterization results of the fracture, combined with the ground stress prediction results and the ground stress direction prediction results, calculate the fracture surface shear stress and effective normal stress, and obtain a fracture stability prediction plane diagram based on the fracture surface shear stress and effective normal stress.

[0097] Optionally, fracture interpretation is performed based on the actual drilling data to identify the fracture development location of the drilling section, including: interpreting the fracture development location of the drilling section through the actual drilling engineering recovery map of the drilling section, FMI imaging logging data, conventional logging data, horizontal section logging data and microseismic monitoring data.

[0098] Optionally, the seismic data includes a time-domain prestack migration gather; and performing elastic parameter inversion based on the seismic data to obtain an elastic parameter body includes: performing elastic parameter inversion using a time-domain prestack migration gather to obtain an elastic parameter body.

[0099] Optionally, the in-situ stress prediction result includes overlying formation pressure; and the method includes:

[0100] Based on the elastic parameter body and the rock mechanics parameter body, a normal compaction curve of density is calculated using a seismic travel time equation;

[0101] Create a density curve using the normal compaction curve of density and the actual measured density curve;

[0102] The overlying formation pressure is calculated using the integral of the density curve.

[0103] Optionally, the geostress prediction result further includes formation pore pressure; and the method includes:

[0104] The formation pore pressure is calculated based on the elastic parameter body and the rock mechanics parameter body using Eaton's empirical formula.

[0105] Optionally, the geostress prediction result also includes horizontal principal stress; the method includes: calculating the horizontal principal stress using the Huang model based on the elastic parameter body and the rock mechanics parameter body.

[0106] Optionally, obtaining a fracture stability prediction plane diagram based on the fracture surface shear stress and the effective normal stress includes: comparing the fracture surface shear stress and the effective normal stress to obtain a comparison result; and drawing a fracture stability prediction plane diagram according to the comparison result.

[0107] The method described in the embodiment of the present invention can guide drilling to avoid areas with high fault slip risk, enhance the guiding role of seismic results in shale gas exploration and development, support overall platform deployment and optimization, and improve the utilization rate of underground resources.

[0108] It will be understood by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Thus, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0109] The present invention is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device produce a device for implementing the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

[0110] These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce a product including an instruction device that implements the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

[0111] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, so that the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

[0112] In a typical configuration, a computing device includes one or more processors (CPUs), input / output interfaces, network interfaces, and memory.

[0113] The memory may include non-permanent memory in a computer-readable medium, random access memory (RAM) and / or non-volatile memory in the form of read-only memory (ROM) or flash RAM. The memory is an example of a computer-readable medium.

[0114] Computer-readable media includes permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store information. The information can be computer-readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer-readable media does not include transitory computer-readable media (transitory media), such as modulated data signals and carrier waves.

[0115] It should also be noted that the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, commodity, or apparatus that includes a series of elements includes not only those elements but also other elements not explicitly listed, or includes elements inherent to such process, method, commodity, or apparatus. In the absence of further limitations, an element defined by the phrase "comprises a ..." does not exclude the presence of other identical elements in the process, method, commodity, or apparatus that includes the element.

[0116] The above are merely embodiments of the present invention and are not intended to limit the present invention. It will be apparent to those skilled in the art that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention are intended to be included within the scope of the claims of the present invention.

Claims

1. A method for seismic assessment of fault stability, characterized in that: The method comprises: Acquire basic seismic data of the drilling section; wherein the basic seismic data of the drilling section includes seismic data and actual drilling data; Performing fracture interpretation based on the actual drilling data to identify fracture development locations in the drilling section; Based on the seismic data, extracting seismic attributes capable of predicting rupture; Calibrate the fracture development position of the drilling section and the seismic attributes to determine a sensitive attribute body, and determine a fracture quantitative characterization result based on the sensitive attribute body; Performing elastic parameter inversion based on the seismic data to obtain an elastic parameter body, and determining a rock mechanics parameter body based on the elastic parameter body; Determining a ground stress prediction result based on the elastic parameter body and the rock mechanics parameter body; Based on the thin plate theory and using the rock mechanics parameter body, geological, mechanical and mathematical models are established, and the three-dimensional finite element difference simulation method is used to determine the prediction results of the ground stress direction; Based on the Mohr-Coulomb theory, on the basis of the quantitative characterization results of the fracture, combined with the ground stress prediction results and the ground stress direction prediction results, the fracture surface shear stress and effective normal stress are calculated, and the fracture stability prediction plane diagram is obtained based on the fracture surface shear stress and effective normal stress.

2. The seismic assessment method of fault stability according to claim 1, characterized in that: Based on the actual drilling data, the fracture interpretation is performed to identify the fracture development location of the drilling section, including: The location of fault development in the drilling section is interpreted through the actual drilling engineering recovery map, FMI imaging logging data, conventional logging data, horizontal section logging data and microseismic monitoring data.

3. The seismic assessment method of fault stability according to claim 1, characterized in that: The seismic data includes a time domain pre-stack migration gather; performing elastic parameter inversion based on the seismic data to obtain an elastic parameter body includes: The elastic parameter inversion is completed using the time domain prestack migration gathers to obtain the elastic parameter volume.

4. The seismic assessment method of fault stability according to claim 1, characterized in that: The ground stress prediction result includes the overlying formation pressure; the method includes: Based on the elastic parameter body and the rock mechanics parameter body, a normal compaction curve of density is calculated using a seismic travel time equation; Create a density curve using the normal compaction curve of density and the actual measured density curve; The overburden pressure is calculated using the integral of the density curve.

5. The seismic evaluation method of fault stability according to claim 4, characterized in that: The in-situ stress prediction result also includes formation pore pressure; the method includes: Based on the elastic parameter body and the rock mechanics parameter body, the formation pore pressure is calculated using Eaton's empirical formula.

6. The seismic assessment method of fault stability according to claim 5, characterized in that: The geostress prediction result also includes horizontal principal stress; the method includes: Based on the elastic parameter body and the rock mechanics parameter body, the horizontal principal stress is calculated using the Huang model.

7. The seismic assessment method of fault stability according to claim 1, characterized in that: The fracture stability prediction plane diagram is obtained based on the fracture surface shear stress and effective normal stress, including: Compare the magnitudes of fracture surface shear stress and effective normal stress to obtain comparative results; A fracture stability prediction plane diagram is drawn according to the comparison result.

8. A seismic assessment device for fault stability, characterized in that: The device comprises: A basic data acquisition module is used to acquire basic seismic data of the drilling section; wherein the basic seismic data of the drilling section includes seismic data and actual drilling data; A fracture interpretation module, used to interpret fractures based on the actual drilling data and identify fracture development locations in the drilling section; A seismic attribute extraction module, used for extracting seismic attributes capable of predicting fractures based on the seismic data; A calibration module, used to calibrate the fracture development position of the drilling section and the seismic attribute, determine a sensitive attribute body, and determine a fracture quantitative characterization result based on the sensitive attribute body; An inversion module, used for performing elastic parameter inversion based on the seismic data to obtain an elastic parameter body, and determining a rock mechanics parameter body according to the elastic parameter body; A geostress prediction module, used for determining a geostress prediction result based on the elastic parameter body and the rock mechanics parameter body; The module for predicting the direction of geostress is used to establish geological, mechanical and mathematical models based on the thin plate theory and the rock mechanics parameter body, and to determine the prediction results of the direction of geostress using the three-dimensional finite element difference simulation method; The fracture stability prediction module is used to calculate the fracture surface shear stress and effective normal stress based on the Mohr-Coulomb theory and the fracture quantitative characterization results, combined with the ground stress prediction results and the ground stress direction prediction results, and obtain the fracture stability prediction plane diagram based on the fracture surface shear stress and the effective normal stress.

9. A processor, characterized in that: A method for seismic assessment of fault stability configured to perform any one of claims 1 to 7.

10. A machine-readable storage medium having instructions stored thereon, characterized in that: When the instructions are executed by a processor, the processor is configured to perform the seismic assessment method of fault stability according to any one of claims 1 to 7.

Images