29 results about "Transverse isotropy" patented technology

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

The invention discloses a Neper-DEM-based apparent crystal rock modeling and calculation method with a bedding structure, relates to the field of numerical calculation of a tunnel engineering technology, and solves the problem that a simulation and calculation method for apparent crystal rocks with transverse isotropy such as gneiss and granite gneiss is lacked in the prior art. The method comprises the following steps: constructing a polycrystal structure with crystal characteristics in Neper, and generating a geometric parameter text of crystal grains from the polycrystal structure; constructing a discrete element rock sample model in the DEM; performing a numerical simulation test on the discrete element rock sample model to obtain a stress-strain curve and a sample failure mode, wherein the numerical simulation is realized by adopting a Brazilian splitting test and a triaxial test; according to a numerical simulation result, discrete element sample calculation parameters are calibrated, and the effectiveness of the modeling and calculation method of the discrete element rock sample model is verified; according to the modeling method, construction and assignment of the crystal structure and the bedding structure are achieved at the same time, so that the rock structure is closer to a real rock structure.

A method is described for generating high-resolution images of transversely isotropic mechanical properties and attenuation properties of tissues associated with measured compressional waves. A pressure wave is transmitted to a region containing fibers that are oriented with transverse isotropy. Waves are received that propagate after the pressure wave has impinged upon the fibers. An initial velocity and attenuation model is created that takes into account the transverse isotropy of the fibers. Full Waveform Inversion (FWI) is used to iteratively minimize a difference between the received data and the initial velocity and attenuation model to create an image of the region that takes into account the transverse isotropy of the fibers. The image has a higher resolution than if created using the initial velocity and attenuation model.

Systems and methods for using cross-well seismic data to image reservoir structures illuminated with sources located in a lateral well and receivers located in one or more nearby lateral wells. The systems and methods include numerical FWI algorithms and workflows based on an elastic vertical transverse isotropy (VTI) anisotropic full waveform inversion (EFWI) engine. The EFWI engine is used for inversions based on the cross-well seismic data and additional data (e.g., well logs, vertical seism profiles). Inversion results include 2D / 3D maps of elastic properties (e.g., velocity, anisotropy, density, attenuation) of subsurface. The EFWI engine includes a wave propagation modeling accounting for various seismic waves propagating in the subsurface.

The invention discloses a strong transverse isotropic medium elastic wave velocity prediction method and device, and relates to the technical field of geophysical oil-gas exploration. And constructing an elastic wave velocity model by using the reservoir target section rock attribute information, and predicting the elastic wave velocity according to the elastic wave velocity model. The elastic wave velocity model with the fracture weakness as the independent variable is provided, the elastic wave velocity can be conveniently determined according to the fracture parameters, the method can be suitable for the high-anisotropy condition, and under the high-anisotropy condition, the seismic elastic wave velocity prediction result provided by the invention better coincides with the accurate value, and the application range is wider. In the process of establishing the elastic wave velocity model, the rock attribute information of the target section of the reservoir is fully utilized, the corresponding rock physical model is accurately constructed, and the corresponding reservoir rock and the properties of the fluid contained in the reservoir rock can be accurately determined according to the seismic response characteristics.

The method comprises the following steps: acquiring a point scattering model and a reverse time migration image of a VTI medium in a target area, wherein the VTI medium is a transverse isotropic medium of a vertical symmetry axis in the target area; determining a point spread function data volume of the VTI medium according to the point scattering model; transforming the point spread function data body and the reverse time migration image to a frequency wavenumber domain by using Fourier transform to obtain a wavenumber domain reverse time migration image block and a wavenumber domain point spread function data block; and determining a least square image of the VTI medium according to the wave number domain reverse time migration image block and the wave number domain point spread function data block. According to the method, VTI medium least square migration imaging is realized, the influence of anisotropy on construction imaging positioning is corrected, the influence on the imaging position and amplitude is eliminated, and the imaging precision is improved.

The present application provides a method, apparatus, electronic device, and storage medium for determining fracture density, which relates to the technical field of geological exploration. In the present application, when it is determined that the fracture dip angle in the target area satisfies a preset fracture dip angle condition, a first calculation method for the azimuthal seismic reflection coefficient corresponding to the target area is obtained; the first calculation method is the calculation method for the azimuthal seismic reflection coefficient under a horizontally transverse isotropic medium; based on the mapping relationship between at least one calculation parameter included in the first calculation method and the fracture density parameter, the first calculation method is modified to obtain a second calculation method for the azimuthal seismic reflection coefficient; based on the second calculation method and the mapping relationship between the azimuthal elastic impedance and the azimuthal seismic reflection coefficient, a third calculation method corresponding to the azimuthal elastic impedance is determined, and the fracture density in the target area is determined based on the Fourier series corresponding to the third calculation method, improving the accuracy of fracture density prediction.

A method that includes disposing an acoustic logging tool in a borehole. The acoustic logging tool comprises one or more transmitters and one or more receivers. The method may further comprise taking one or more acquisitions with the acoustic logging tool as the acoustic logging tool traverses through the borehole, creating an azimuth rotation angle array of one or more angles, from the one or more acquisitions, and applying a trial angle selected from the one or more angles of the azimuth rotation angle array to calculate a fast shear waveform.

The present invention discloses a PS-wave VTI medium dynamic correction method and device based on segmented velocity modeling. The method includes: acquiring seismic data of a target transversely isotropic medium to be dynamically corrected, and then organizing to obtain a common conversion point gather and a common midpoint gather; analyzing the common midpoint gather to obtain the P-wave velocity and the P-wave correction velocity; performing velocity analysis iteration on the common conversion point gather, and then realizing segmented velocity analysis modeling through the ratio of offset to depth information, and gradually realizing VTI medium dynamic correction based on the increment of the offset-depth ratio. The embodiments of the present invention can accurately perform PS-wave VTI medium dynamic correction based on segmented velocity modeling, and can be widely applied to the field of data processing technology.

The invention discloses a seismic four-parameter linear direct inversion method based on a transverse isotropic medium reflection coefficient precision formula, and belongs to the technical field of unconventional reservoir seismic exploration. According to the method, an accurate Graebner reflection coefficient equation is deduced again, four pseudo-stiffness coefficients are introduced to re-characterize the reflection coefficient, and the number of to-be-inverted parameters is reduced from 5 to 4, so that the discomfort of an inverse problem is reduced. In order to improve the calculation efficiency of inversion, the partial derivative of the positive operator after the density item is eliminated is deduced to realize linear inversion of four parameters. In order to improve the precision of anisotropy parameter estimation, an indirect inversion strategy is adopted, four pseudo-stiffness coefficients are obtained through inversion, and then the anisotropy parameters epsilon and delta are estimated through inversion results. The feasibility of the inversion method is verified through a synthetic data test.

The invention discloses a torsional vibration analysis method for a pile foundation in transverse isotropic unsaturated soil. The method is different from the previous assumption that the pile-soil interface is in complete contact and has no relative slip, and the relative slip between the pile-soil contact surfaces is simulated by using the Kelvin model, so that the theoretical model better conforms to the practical engineering application. On the basis of a Biot three-phase porous medium framework and a fractional derivative theory, viscoelasticity and transverse isotropy characteristics of a soil framework and viscosity and inertia coupling effects among phases are considered at the same time, and a dynamic control equation described by fractional derivative viscoelasticity stress-strain constitutive description is deduced. And deducing an analytic solution of the torsional vibration response of the pile foundation in the frequency domain and a semi-analytic solution under half-sine pulse excitation in the time domain by utilizing a separation variable method, inverse Fourier transform and a convolution theorem. According to the method, the defects of longitudinal waves can be overcome, and theoretical guidance is provided for improving the accuracy and reliability of pile body integrity detection.

The invention provides a multi-wave joint inversion method and device, electronic equipment and a storage medium. The multi-wave joint inversion method comprises the steps of determining a longitudinal wave-longitudinal wave angle gather and a longitudinal wave-transverse wave angle gather in a longitudinal wave-longitudinal wave angle gather time domain in seismic data; determining formation parameters of a wellhead of the receiving well, and determining an initial inversion model according to the formation parameters of the wellhead; according to the initial inversion model, determining a longitudinal wave-longitudinal wave synthesis record and a longitudinal wave-transverse wave synthesis record by using an accurate vertical transverse isotropic medium reflection coefficient equation; determining a real stratum model, determining relationships between the longitudinal wave-longitudinal wave synthesis record and the longitudinal wave-longitudinal wave angle gather and between the longitudinal wave-transverse wave synthesis record and the longitudinal wave-transverse wave angle gather by using a Bayesian framework, and determining an optimal model of the real stratum model by using a maximum posterior probability; and linearizing the accurate vertical and transverse isotropic medium reflection coefficient equation by using a Gaussian Newton method, determining the update quantity of the initial inversion model, and updating the initial inversion model by using the update quantity.

The invention discloses an earthquake forward modeling method and device, electronic equipment and a storage medium. The method comprises the following steps: determining target depth domain logging data of a target logging; determining a frequency-slowness domain reflection coefficient based on the target depth domain logging data; determining a frequency domain wavelet in a target seismic record related to the target depth domain logging data, and obtaining a time slowness domain seismic record based on the frequency slowness domain reflection coefficient and the frequency domain wavelet; and finally, obtaining a corresponding relation between the horizontal slowness and the incident angle of the propagation waveform in the target logging, and obtaining a time angle domain seismic record based on the corresponding relation and the time slowness domain seismic record. According to the technical scheme, the time angle domain seismic record is accurately obtained through the frequency slowness domain reflection coefficient, the frequency domain wavelet and the corresponding relation between the horizontal slowness and the incident angle, so that the seismic record is accurately obtained, and the problem that the seismic record obtained through simulation under the influence of vertical transverse isotropy is inaccurate is solved.

This application provides a method, device, and storage medium for predicting fracture density based on azimuth anisotropy, belonging to the field of geophysical research technology. The method includes: substituting fracture-related test data into a prediction formula to calculate the P-wave reflection coefficient. The prediction formula is an approximate formula for the P-wave reflection coefficient of a transversely isotropic medium, and the right-hand side variable of the prediction formula includes at least the fracture density in different directions; extracting well-side seismic trace data from azimuth-based stacked traces and deconvolving it to obtain a seismic wavelet; calculating the P-wave reflection coefficient data volume of the target work area based on the seismic wavelet and azimuth-based stacked traces; and inverting the fracture density in different directions of the target work area using an interpolated initial model as a constraint. The above method is based on an improved prediction formula, whose right-hand side variable includes the fracture density in different directions, realizing direct inversion of fracture density, reducing inversion time and accumulated errors, and improving the efficiency and accuracy of fracture density prediction.

The invention relates to the field of building structure engineering, and discloses a deflection calculation method of a web perforated steel-bamboo composite beam, which comprises the following steps of: determining geometric parameters, material parameters and perforated sizes of the steel-bamboo composite beam; mechanical property parameters of the steel and the bamboo plywood are measured, and the overall flexural rigidity of the composite beam is calculated; according to the loading conditions, calculating the overall deflection without tapping and the local deflection under the influence of tapping; superposing the non-tapping deflection and the tapping deflection to obtain the overall deflection distribution of the composite beam; and determining the maximum deflection value and the position of the composite beam. According to the method, the superposition model of the deflection of the non-perforated area and the deflection of the perforated area is established, the transverse isotropic characteristic of the bamboo, the rigidity of the steel and the secondary bending moment distribution of the perforated area are comprehensively considered, the influence of tapping on the overall deflection can be accurately calculated, the tapping arrangement design is optimized, and a theoretical basis is provided for structural design and checking of the steel-bamboo composite beam.

The present invention discloses a method and device for predicting elastic wave velocity in a strongly transversely isotropic medium, and relates to the technical field of geophysical oil and gas exploration. An elastic wave velocity model is constructed using the rock attribute information of the target section of the reservoir, and the elastic wave velocity is predicted based on the elastic wave velocity model. The present invention provides an elastic wave velocity model in which the elastic wave velocity uses the fracture weakness as an independent variable, which is convenient for determining the elastic wave velocity based on the fracture parameters and can be applied to strong anisotropy conditions. Moreover, in the case of strong anisotropy, the seismic elastic wave velocity prediction results provided by the present invention are more consistent with the precise values ​​and have a wider range of applications. In the process of establishing the elastic wave velocity model, the rock attribute information of the target section of the reservoir is fully utilized to accurately construct the corresponding rock physics model, which can accurately determine the corresponding reservoir rock and the fluid properties contained therein based on the seismic response characteristics.

The invention discloses a single-frame composite structure illumination obvious micro-imaging method based on ensemble learning. Single-time transverse isotropic spectrum modulation is achieved through an efficient six-beam interference composite structure illumination strategy, an optical device of a structured light illumination microscope (SIM) does not need to be modified, and therefore the number of original images is reduced by 9 times in the physical sense. In addition, the problem that the super-resolution reconstruction is unsuitable for inversion is solved by integrating the sub-networks of different frequency component characteristics in different domains through integrated learning, and the super-resolution image reconstruction with higher quality is realized in a low signal-to-noise ratio environment at a 9-time imaging speed of a traditional illumination mode. Due to higher imaging speed, less light damage, higher reconstruction quality and better noise immunity, the device becomes an efficient and powerful imaging tool, and can be used for studying the dynamic state of a nanoscale fine structure in living cells.

The invention discloses a DAS data image generation method and device for underground structure visualization. Comprising the following steps: constructing a three-dimensional coordinate system, and obtaining an original sound wave equation, a strain rate parameter and a seismic source parameter of a vertical and transverse isotropic medium; simplifying the strain-displacement relational expression to obtain a conversion relation between the axial strain rate and the velocity component; speed components in the original acoustic wave equation are replaced based on the conversion relation, and an anisotropic acoustic wave equation suitable for DAS data is constructed; deducing a seismic source wave field extrapolation equation and a detection point wave field extrapolation equation according to the anisotropic acoustic wave equation; respectively inputting the focus parameter and the strain rate parameter into corresponding extrapolation equations to obtain a focus pressure wave field and a detection point pressure wave field; and performing mutual-closing imaging processing on the two types of pressure wave fields to obtain an initial result, and performing optimization processing to obtain an underground structure imaging result of the target DAS data. According to the invention, the precision and reliability of DAS data underground structure imaging under complex geological conditions are improved.

Methods and systems for determining in-situ stresses in anisotropic rocks are presented. The methods consider both anisotropic rock properties, geothermal and tectonic effects. They calculates in-situ stresses for subsurface rocks with anisotropies and non-isothermal effects, so that they can be applied to geothermal energy and geo-energy. Horizontal stresses in the vertical transverse isotropy (VTI) rock and in the horizontal transverse isotropy (HTI) rock are obtained for calculating in-situ stresses in naturally fractured rocks. Compared with the conventional isotropic model, the method applicable to VTI rocks predicts a higher minimum horizontal stress and a higher maximum horizontal stress, which is suitable for shales and other laminated formations. The method applicable to HTI rocks gives a lower minimum horizontal stress than the conventional model. Geothermal temperature effects are also integrated into the methods so that the methods are applied to geothermal energy.

A method that includes disposing an acoustic logging tool in a borehole. The acoustic logging tool comprises one or more transmitters and one or more receivers. The method may further comprise taking one or more acquisitions with the acoustic logging tool as the acoustic logging tool traverses through the borehole, creating an azimuth rotation angle array of one or more angles, from the one or more acquisitions, and applying a trial angle selected from the one or more angles of the azimuth rotation angle array to calculate a fast shear waveform.

The present application relates to the technical field of oil exploration, and more particularly to a method and system for modeling earth stress based on transverse isotropy; comprising the following steps: S1, obtaining well logging data of a study area well, processing and correcting missing sections of the well logging data to obtain processed well logging data; S2, calculating formation pore pressure based on the processed well logging data obtained in step S1; S3, calculating elastic parameters of a transversely isotropic medium, the elastic parameters including Young's modulus and Poisson's ratio; S4, establishing an earth stress model according to the formation pore pressure obtained in step S2 and the elastic parameters obtained in step S3; the present application is suitable for high-precision earth stress calculation of super-deep drilling complex lithology.

The present invention discloses a dynamic correction method and device for PP wave VTI media based on segmented velocity modeling. The method includes: acquiring seismic data of a target transversely isotropic medium to be dynamically corrected, and then organizing to obtain a target gather; performing velocity analysis on the target gather, and performing velocity and time information conversion to obtain depth information corresponding to each seismic data in the target gather; obtaining a deviation-depth ratio based on the ratio of the offset to the depth information; cutting the target gather based on the deviation-depth ratio to obtain gather segments; performing velocity analysis on the gather segments to obtain velocity information; determining a deviation-depth ratio increment corresponding to each seismic data in the gather segments based on a preset first deviation-depth ratio threshold value, and further obtaining a P-wave anisotropic velocity; and then obtaining a target travel time, and performing dynamic correction on the target transversely isotropic medium according to the target travel time. The present invention can accurately perform dynamic correction for PP wave VTI media and can be widely applied to the field of data processing technology.

The application relates to the field of building structure engineering and discloses a deflection calculation method for a web-opening steel-timber composite beam, which comprises the following steps: determining the geometric parameters, material parameters and opening size of the steel-timber composite beam; measuring the mechanical property parameters of steel and bamboo plywood, and calculating the overall bending stiffness of the composite beam; respectively calculating the overall deflection without openings and the local deflection under the influence of openings according to loading conditions; superimposing the deflection without openings and the deflection with openings to obtain the overall deflection distribution of the composite beam; and determining the maximum deflection value and the position of the composite beam. Through the establishment of the superposition model of the deflection of the non-opening and opening areas, the transverse isotropic characteristics of the bamboo, the steel stiffness and the secondary bending moment distribution of the opening area are comprehensively considered, the influence of the openings on the overall deflection can be accurately calculated, the opening arrangement design is optimized, and a theoretical basis is provided for the structure design and checking of the steel-timber composite beam.

The application discloses a Neper-DEM-based modeling and calculation method of phanerocrystalline rocks with bedding structure, relates to the numerical calculation field of tunnel engineering technology, and solves the problem that the prior art lacks a simulation and calculation method of phanerocrystalline rocks such as gneiss and granulitic gneiss with transverse isotropy; the application comprises the following steps: constructing a polycrystal structure with crystal characteristics in Neper, and then generating the polycrystal structure into a geometric parameter text of a crystal grain; constructing a discrete element rock sample model in DEM; performing numerical simulation test on the discrete element rock sample model to obtain a stress-strain curve and a sample failure mode, wherein the numerical simulation is realized by adopting a Brazilian split test and a triaxial test; calibrating discrete element sample calculation parameters according to the numerical simulation result, and verifying the effectiveness of the modeling and calculation method of the discrete element rock sample model; and the application realizes the construction and assignment of the crystal structure and the bedding structure at the same time in the modeling method, so that the rock structure is closer to the real rock structure.

The invention discloses an improved friction pile torsional vibration analysis method and system, a storage medium and application of the improved friction pile torsional vibration analysis method and system, relates to pile foundation engineering dynamic analysis, and mainly solves the key but often neglected influence factor of a sediment layer with limited thickness between a pile end and bedrock. By introducing a virtual unsaturated soil pile method, a pile body virtually extends to a bedrock surface, and the FUSP maintains the fractional order viscoelasticity characteristic of surrounding soil. The soil body control equation integrates viscoelasticity characteristics of three-phase interaction, transverse isotropy and fractional calculus, and unified modeling of the friction pile and the end bearing pile is achieved. An analytic solution of frequency domain torsional impedance is deduced through a variable separation method and an eigenfunction expansion method, and a semi-analytic time domain response under semi-sine pulse excitation is obtained in combination with inverse Fourier transform and a convolution theory. The method can provide a high-precision theoretical analysis tool for aseismic design and dynamic response prediction of the friction pile foundation in the unsaturated land area.

The invention relates to the field of exploration geophysics, and discloses a viscous sound reverse time migration method in an inclined transverse isotropic medium, comprising the following steps: S1, setting an observation system, and inputting model parameter fields including a velocity field, an anisotropy parameter field and an attenuation anisotropy parameter field; s2, performing grid discretization on the model parameters according to the model parameter field to obtain model parameters at each grid point; s3, setting a pure viscous sound TT I wave equation with decoupling amplitude attenuation and a phase frequency dispersion operator, and constructing a high-precision wave field propagation operator; and S4, realizing Q compensation reverse time migration by using a pure viscous sound TT I wave equation with decoupling amplitude attenuation and phase frequency dispersion operators. Therefore, a pure viscous sound TT I wave equation based on memory variable expression is deduced, separation of amplitude attenuation and phase dispersion is achieved, efficient solving is achieved through a finite difference method, and the method is suitable for industrial application.

The invention provides a side slope safety evaluation method, system and device considering anisotropic damage of columnar jointed rock mass and a medium, a first main strain and a third main strain are used as damage evaluation factors, and threshold values of the damage evaluation factors are calculated; calculating an evaluation factor value of each unit through finite difference; judging whether the first main strain and the third main strain exceed threshold values or not, and calculating a unit damage variable value; and obtaining the damage distribution condition of the columnar jointed rock slope through the damage variable value of each unit. According to the method, the transverse anisotropy of the columnar joint rock slope and the properties of the rock slope are considered, the stability of the rock slope is described by adopting a damage concept, the first principal strain and the third principal strain of the rock mass are introduced as damage evaluation factors, the anisotropy of the columnar joint is fully reflected, and the stability of the rock slope is evaluated. The damage condition of the columnar jointed rock slope can be reflected more accurately, and the method has important engineering significance and application value for stability evaluation of the columnar jointed rock slope and prevention and reinforcement of the slope.

The invention provides a fracture density determination method and device, electronic equipment and a storage medium, and relates to the technical field of geological exploration. The method comprises the steps that when it is determined that a crack inclination angle in a target area meets a preset crack inclination angle condition, a first calculation mode of an azimuth seismic reflection coefficient corresponding to the target area is acquired; the first calculation mode is a calculation mode of orientation seismic reflection coefficients under a horizontal transverse isotropic medium; modifying the first calculation mode based on a mapping relation between at least one calculation parameter included in the first calculation mode and the fracture density parameter to obtain a second calculation mode of the azimuth seismic reflection coefficient; and determining a third calculation mode corresponding to the azimuth elastic impedance based on the second calculation mode and the mapping relation between the azimuth elastic impedance and the azimuth seismic reflection coefficient, and determining the fracture density in the target area based on the Fourier series corresponding to the third calculation mode, thereby improving the accuracy of fracture density prediction.

The invention provides a shale formation modeling method and system suitable for hydraulic fracture propagation simulation, and belongs to the technical field of oil and gas reservoir development. The method comprises the following steps: dividing a lamina into three states according to a shale core test result, establishing a lamina model for the shale lamina in different states, and carrying out lamina state conversion under different stress conditions. According to the method, definite state division is carried out on the shale formation, and modeling is carried out on each state, so that the state can participate in fracturing coupling stress field calculation; the influence of the stripe layer which is not fully opened on the property of the shale is represented through transverse isotropy, so that the complexity caused by modeling each stripe layer is avoided; under a certain condition, the lamina is activated to become a solid crack, and complex crack characteristic simulation of lamina shale can also be realized.